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... When the number of studies allowed for it, we examined the heterogeneity of the effect sizes for each outcome across studies. We examined heterogeneity by using I 2 and Q as well as τ 2 and the visualization of the forest plots (Borenstein, Hedges, Higgins, & Rothstein, 2009). However, we only interpreted heterogeneity for meta-analyses that included four or more studies. ...
... It is possible that the included studies with a small sample size present a biased overview of the impact of specific teacher practices and parental involvement on EGL outcomes because of publication bias. The unusual high statistical significance in the studies with a smaller sample size shows the potential for publication bias in studies with a focus on teacher practices and parental involvement (Borenstein et al., 2009). However, we did not conduct a formal test of publication bias because of the small number of studies for which we could estimate effect sizes. ...
... The results of our analysis may be vulnerable to publication bias. As discussed in previous sections, some of the smaller studies present effect sizes that may be overestimates, which could be an indication of publication bias (Borenstein et al., 2009). In addition, the Egger test showed some indications for publication bias in impact estimates of the ICT programs. ...
... Meta-analysis is essential to cumulative science. 1 However, a common concern to meta-analysis is the overestimation of effect size due to publication bias, the preferential publishing of statistically significant studies. 2,3,4,5,6 In addition, this effect size exaggeration can be further increased by questionable research practices, that is, researchers' tendency to manipulate their data in a way that increases the effect size and the evidence for an effect. ...
... For example, John and colleagues 9 estimate that about 78% of researchers failed to disclose all dependent measures and around 36% stopped data collection after achieving a significant result 1 (but see Fiedler & Schwarz 10 who argued that the survey by John and colleagues 9 overestimated QRPs prevalence). 1 As measured by the geometric mean over researchers' self-admission rate, prevalence estimate (the estimate for the percent of other researchers who had engaged in a behavior), and an admission estimate. For the admission estimates the number of people reporting to have engaged in a given QRP was divided by researchers estimate for the proportion of other researchers that would admit that they engaged in this QRP. ...
Publication bias is a ubiquitous threat to the validity of meta‐analysis and the accumulation of scientific evidence. In order to estimate and counteract the impact of publication bias, multiple methods have been developed; however, recent simulation studies have shown the methods' performance to depend on the true data generating process, and no method consistently outperforms the others across a wide range of conditions. Unfortunately, when different methods lead to contradicting conclusions, researchers can choose those methods that lead to a desired outcome. To avoid the condition‐dependent, all‐or‐none choice between competing methods and conflicting results, we extend robust Bayesian meta‐analysis and model‐average across two prominent approaches of adjusting for publication bias: (1) selection models of p‐values and (2) models adjusting for small‐study effects. The resulting model ensemble weights the estimates and the evidence for the absence/presence of the effect from the competing approaches with the support they receive from the data. Applications, simulations, and comparisons to preregistered, multi‐lab replications demonstrate the benefits of Bayesian model‐averaging of complementary publication bias adjustment methods. This article is protected by copyright. All rights reserved.
... This study may be affected by several types of bias, as occurs in all meta-analyses, particularly retrospective meta-analyses, such as this one. 45,46 One of the problems of including unconventional perfusion flaps performed in different animal species using multiple vascular patterns is that there is a variable degree of inherent heterogeneity. In fact, this heterogeneity was confirmed for both population estimates using the Cochran Q test (p < 0.001). ...
... It is widely accepted that the most efficacious way to downplay the effect of publication bias is to perform a systematic and comprehensive review of the literature, as was performed in this study. 45,46 In addition, the authors have strictly adhered to the widely accepted Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist for systematic reviews and meta-analyses to minimize the risk of committing methodologic mistakes. 47,48 Finally, the authors believe that although this article has the significant merit of providing a synthesis of the available literature regarding the use of experimental unconventional perfusion flaps, it contributes only modestly to understanding the mechanisms underlying the survival or necrosis of these flaps, making further studies in this field warranted. ...
Background:
Unconventional perfusion flaps offer multiple potential advantages compared with traditional flaps. Although there are numerous experimental articles on unconventional perfusion flaps, the multiple animal species involved, the myriad vascular constructions used, and the frequently conflicting data reported make synthesis of this information challenging. The main aim of this study was to perform a systematic review and meta-analysis of the literature on the experimental use of unconventional perfusion flaps, to identify the best experimental models proposed and to estimate their global survival rate.
Methods:
The authors performed a systematic review and meta-analysis of all articles written in English, French, Italian, Spanish, and Portuguese on the experimental use of unconventional perfusion flaps and indexed to PubMed from 1981 until February 1, 2017.
Results:
A total of 68 studies were found, corresponding to 86 optimized experimental models and 1073 unconventional perfusion flaps. The overall unconventional perfusion flap survival rate was 90.8 percent (95 percent CI, 86.9 to 93.6 percent; p < 0.001). The estimated proportion of experimental unconventional perfusion flaps presenting complete survival or nearly complete survival was 74.4 percent (95 percent CI, 62.1 to 83.7 percent; p < 0.001). The most commonly reported animal species in the literature were the rabbit (57.1 percent), the rat (26.4 percent), and the dog (14.3 percent). No significant differences were found in survival rates among these species, or among the diverse vascular patterns used.
Conclusion:
These data do not differ significantly from those reported regarding the use of unconventional perfusion flaps in human medicine, suggesting that rabbit, rat, and canine experimental unconventional perfusion flap models may adequately mimic the clinical application of unconventional perfusion flaps.
... We further computed I 2 to estimate the ratio of true heterogeneity to total observed variation. Publication bias, or the tendency that studies with statistically significant results are more likely to find their way into the published literature, was examined by means of funnel plots, with Egger regression and trimand-fill analysis for estimation of the adjusted effect size and of missing studies ( Borenstein et al., 2009b). These procedures are based on the expectation that the publication bias will increase with a smaller sample size. ...
The present meta-analysis investigated the impact of non-invasive stimulation, using transcranial direct current stimulation (tDCS) and transcranial magnetic stimulation (TMS) targeting the posterior cerebellum, on social and emotional mentalizing about others. Prior research has convincingly shown that the posterior cerebellum supports social and emotional cognition. We identified 14 studies targeting the cerebellum with appropriate control conditions (i.e., sham, control site), which exclude general learning effects of the task or placebo effects. The studies included 29 task conditions where stimulation before or during a social or emotional task was applied on healthy samples. The results showed significant evidence that sustained anodal tDCS and TMS generally improved social and emotional performance after stimulation, in comparison with sham or control conditions, with a small effect size. In contrast, cathodal stimulation showed mixed facilitatory and inhibitory results. In addition, short TMS pulses, administered with the aim of interfering with ongoing social or emotional processes, induced a small but consistent inhibitory effect. Control tasks without social or emotional components also showed significant improvement after sustained anodal tDCS and TMS, suggesting that transcranial stimulation of the cerebellum may also improve other functions. This was not the case for short TMS pulses, which did not modulate non-social and non-emotional control tasks. Taken together, this meta-analysis shows that cerebellar neurostimulation confirms a causal role of the cerebellum in socio-emotional cognition, has a small but significant effect on improving socio-emotional skills, and may, therefore, have important clinical applications in pathologies where social and emotional cognition is impaired.
... To confirm the heterogeneity of study level estimates, a Galbraith plot was also constructed. Small study effects and the presence of publication bias were then visualised using funnel plot diagrams, Egger's and Begg's tests (Borenstein et al. 2009). The studies were also classified geographically (north, east, south, central, west, northeast, northwest, southeast, and southwest), and the total prevalence was assessed in six different regions. ...
Unlabelled:
We performed this review to determine the weighted prevalence of equids parasitic infections in Ethiopia. Article searches on parasites of equids were conducted using PubMed, PubMed Central, Google Scholar, Science Direct, Web of Sciences, Scopus, AJOLs and Research Gate. A random effects model was used to estimate the weighted prevalence and to study heterogeneity. The primary searches generated, 3082 potential studies, of which 66 reports met the inclusion criteria and were included in the meta-analysis. There were 32 reports involving two or more equids species, eighteen on donkeys, and sixteen on horses. Moreover, fifty of the reports mentioned helminth infections in equids, thirteen on protozoans, and three on ectoparasites. The estimated weighted prevalence of parasitic infections in equids was 58.3% (95% CI 50.8-65.4%, I2 = 99%). Helminths were the most prevalent parasites in equids, accounting for 77.1% (95% CI 71.4%, 82%, I2 = 98.5%), followed by ectoparasites at 35.4% (95% CI 33.4-37.52%, I2 = 88.2%) and haemoparasites (protozoans) at 10.84% (95% CI 6.6%, 17.3%, I2 = 98.1%). Furthermore, with a prevalence of 82.3% (95% CI 75.9-87.3%, I2 = 97.4%), donkeys were the most affected equids with helminth parasites. From the reports, we found forty-three species of helminth parasites affecting equids, including thirty-four nematode species (Strongylus, Cyathostomum, Coronocyclus, Cylicocyclus, Cylicostephanus, Trichostrongylus, Oesophagodontus, Strongyloides, Triodontophorus, Gyalocephalus, Poteriostomum, Dictyocaulus, Oxyuris, Habronema, Draschia, Parascaris, Setaria, and Probstmayria species), three trematodes (two Fasciola and one Gastrodiscus species), three cestodes (two Anoplocephala and one Anoplocephaloides species) and three botfly larvae (one Rhinoestrus and two Gasterophilus species). Trypanosoma species (T. congolense, T. vivax, T. brucei, T. equiperdum, and T. evansi), piroplasms (Theileria equi and Babesia caballi), and Eimeria species have also been reported to affect equids. Ticks (Amblyomma variegatum, A. gemma, Rhipicephalus decoloratus, R. evertisi evertisi, R. pulchellus, R. muhsame, R. sanguineus, Hyalomma rufipes, and Hy. truncatum) and lice (Bovicola equi and Haematopinus asini) were the ectoparasites recorded to affect equids. The risk of publication bias across studies was likely to be high due to differences in publication year and diagnostic techniques. In conclusion, parasitic infections of equids are common in Ethiopia and are caused by a variety of parasite species, putting the performance and well-being of these packing animals at risk. Therefore, more research is needed to identify infection risk factors and raise awareness of the consequences of parasitism in order to provide strategies to mitigate the problems in equids.
Supplementary information:
The online version contains supplementary material available at 10.1007/s12639-023-01598-3.
... Finally, publication bias was analyzed by using a funnel plot to identify whether studies with large ESs were more likely to be published than those with smaller ESs. The publication bias affected the mean ES of all included studies (Borenstein, Hedges, Higgins, & Rothstein, 2009). Duval and Tweedie's (2000) trim and fill method (Duval & Tweedie, 2000) was also used to obtain an unbiased estimate of the ES. ...
This study assessed Robert Sternberg's theory of successful intelligence (TSI) training in teaching and learning situations to improve academic achievement, triarchic (analytical, creative, practical) thinking, and socioemotional outcomes. The analyses included all references from several databases (Web of Science, ProQuest, Elsevier, Google Scholar, and bibliographies of related articles) from 1998 to 2019 that implemented the successful intelligence training program in a variety of ways. Possible moderators, selection criteria, subject areas, and grade levels were investigated. A total of 24 studies (19 articles) were included in the meta-analysis. The results revealed that successful intelligence training has a positive effect on students' overall achievement, g = 0.63, SE = 0.11, 95% confidence interval (CI) [0.41, 0.85], k = 24, z = 5.98, p < .001, under a random-effect model. After adjusting for publication bias, the effect size (ES) g was 0.35, SE = 0.12, 95% CI [0.10, 0.60]. The ES was the largest for socioemotional outcomes, followed by triarchic outcomes and then achievement outcomes. High-IQ-based selected participants received higher ES than teacher-selected participants. Regarding subject areas, science and general triarchic training differed significantly. Among the grade levels, high-school level and primary level differed significantly. Moreover, intervention duration negatively moderated the ES significantly. Gender did not moderate the ES. All student participants benefited from the successful intelligence training program, and this benefit was greater for gifted and older students. This finding suggests that TSI training educators provide a more detailed, structured, and authentic problem situation to be more effective instead of academic problems.
... Heterogeneity measures Q and I2 statistics are reported in the graphs. Publication bias for each meta-analysis was assessed via visual inspection of funnel plots, using Egger's regression and the nonparametric trim and fill method [27]. All analyses were performed using Stata version 16 and R version 3.6.2. ...
Impaired upper airway sensation may contribute to obstructive sleep apnea (OSA) pathophysiology and could represent a therapeutic target. However, the extent of impaired sensation and its functional role in OSA pathogenesis remains unclear. This study aimed to: (1) evaluate methods of upper airway sensory testing in people with OSA, (2) compare upper airway sensation in people with and without OSA and (3) investigate the potential relationship between upper airway sensation and OSA severity. Major electronic databases were searched for studies that reported methods of upper airway sensory testing in people with OSA (n=3,819). From the selected studies (n=38), information on the type of sensation, testing methods, validity and test-retest reliability were extracted. Meta-analyses were performed on case-controlled studies and studies that investigated potential relationships between upper airway sensation and OSA severity. Seven categories of sensory tests were reported: olfactory, gustatory, chemical, tactile, vibratory, thermal and perioral neuro-sensation. Testing methods varied widely across studies. No tests were validated in OSA. People with OSA had impaired upper airway sensation to airflow (p=0.0002), chemical (p=0.0001), gustatory (p=0.009), olfactory (p=0.04), tactile (p=0.0001) and vibratory (p=0.005) stimuli. Upper airway sensory impairment increased with OSA severity (p<0.001). These findings suggest that, while variable across testing methods, people with OSA have impaired upper airway sensation, which is related to increased OSA severity. Development of valid and reliable upper airway sensory testing methods that relate to upper airway function in people with OSA are required to inform future clinical and research practices and identify potential therapeutic targets.
... The lack of significant dispersion in the sample among the selected studies could explain the non-significant publication bias in the regression test. Evidence suggests that non-significant eggers' regression tests can be caused by a lack of substantial dispersion and a small sample size [58].The other aim of this systematic review and meta-analysis was to identify the commonest associated factors with PPMC utilization in Ethiopia. Prenatal (antenatal) family planning counseling, postnatal care utilization, spouse communication on family planning, resumption of menses, and resumption of sexual activity were the most common factors that contributed to PPMC utilization in Ethiopia. ...
Objective
This study aimed to estimate the pooled prevalence and factors associated with postpartum modern contraceptive use in Ethiopia.
Design
Systematic Reviews and Meta-Analysis.
Method
PubMed, MEDLINE, EMBASE, Hinari, Google Scholar, direct Google search, African Journal Online (AJOL), an online repository, and gray kinds of literature were used for searching. This meta-analysis included eighteen cross-sectional studies. The quality appraisal criterion of the Joanna Briggs Institute (JBI) was employed to critically appraise papers.The I2 statistics were used to test heterogeneity and subgroup analysis was computed with the evidence of heterogeneity. The Egger test with funnel plot was used to investigate publication bias. The "generate" command in STATA was used to calculate the logarithm and standard error of the odds ratio (OR) for each included study.Then odds ratio (OR) with a 95% confidence interval (CI) was presented.
Result
Eighteen studies were included in the systematic review and meta-analysis. The pooled prevalence of modern postpartum family planning utilization among postnatal women in Ethiopia was 45.44% (95%CI: 31.47, 59.42).
Prenatal family planning counseling (AOR=3.80; 95%CI: 2.70, 5.34), postnatal care utilization (AOR=3.07; 95%CI: 1.39, 6.77), spouse communication on family planning (AOR=1.86;95%CI:1.36,2.54), resumption of menses (AOR=4.20;95%CI: 2.95, 5.99), and resumption of sexual activity (AOR=3.98;95%CI: 2.34, 6.79) were associated factors to uptake modern postpartum family planning among postnatal women.
Conclusion
The pooled prevalence of postpartum modern contraceptive use was low. The most common factors significantly associated with postpartum modern contraceptive use were prenatal family planning counseling, postnatal care utilization, spouse communication on family planning, resumption of menses, and resumption of sexual activity were the commonest factors significantly associated with postpartum modern contraceptive use.
... Finally, publication bias was analyzed by using a funnel plot to identify whether studies with large ESs were more likely to be published than those with smaller ESs. The publication bias affected the mean ES of all included studies (Borenstein, Hedges, Higgins, & Rothstein, 2009). Duval and Tweedie's (2000) trim and fill method (Duval & Tweedie, 2000) was also used to obtain an unbiased estimate of the ES. ...
This study assessed Robert Sternberg's theory of successful intelligence (TSI) training in teaching and learning situations to improve academic achievement, triarchic (analytical, creative, practical) thinking, and socioemotional outcomes. The analyses included all references from several databases (Web of Science, ProQuest, Elsevier, Google Scholar, and bibliographies of related articles) from 1998 to 2019 that implemented the successful intelligence training program in a variety of ways. Possible moderators, selection criteria, subject areas, and grade levels were investigated. A total of 24 studies (19 articles) were included in the meta‐analysis. The results revealed that successful intelligence training has a positive effect on students' overall achievement, g = 0.63, SE = 0.11, 95% confidence interval (CI) [0.41, 0.85], k = 24, z = 5.98, p < .001, under a random‐effect model. After adjusting for publication bias, the effect size (ES) g was 0.35, SE = 0.12, 95% CI [0.10, 0.60]. The ES was the largest for socioemotional outcomes, followed by triarchic outcomes and then achievement outcomes. High‐IQ‐based selected participants received higher ES than teacher‐selected participants. Regarding subject areas, science and general triarchic training differed significantly. Among the grade levels, high‐school level and primary level differed significantly. Moreover, intervention duration negatively moderated the ES significantly. Gender did not moderate the ES. All student participants benefited from the successful intelligence training program, and this benefit was greater for gifted and older students. This finding suggests that TSI training educators provide a more detailed, structured, and authentic problem situation to be more effective instead of academic problems.
... Thereafter, all effect sizes were transformed into Fisher's z scale. Fisher's z scale was selected mainly because it normalizes and stabilizes the sampling variance of Pearson correlation coefficients (Borenstein et al., 2009). ...
Background Studies have reported mixed findings on the relationship between posttraumatic growth (PTG) and health-related quality of life (HRQOL) in cancer survivors. This review aims to give an overview of these studies and to identify potential study- and sample-level factors that could contribute to the heterogeneity of those findings on the relationship between PTG and HRQOL in cancer survivors.
Methods Multiple electronic databases were systematically searched using the concepts ‘posttraumatic growth’, ‘cancer’, and ‘health-related quality of life’. Eligible studies (published until 2018) were reviewed, quality-assessed, and effect sizes were extracted and synthesized.
Results Of the 37 included articles, 22 received a rating of ‘weak’, 11 ‘moderate’ and 4 ‘strong’ in study quality assessment. The overall sample comprised 7954 individuals, mean age of 55.30 years, >50% females, predominantly breast cancer, and survivors mainly within 5 years post-diagnosis. The synthesized results revealed a positive association between PTG and HRQOL (Fisher's Z=0.16) on a total scale, with significant high heterogeneity (I²=75%). Variations in HRQOL measurement and methodological inconsistency contributed to study-level differences of effect sizes. Sample-level characteristics such as geographic region, smaller sample sizes (n < 100) and so on contributed to heterogeneity.
Limitations Studies assessing the relationship between PTG and HRQOL were heterogeneous, of weak study quality generally, and results were difficult to combine.
Conclusions Most studies found a positive relationship between the factors suggesting that PTG may play a role for successful coping following cancer. However, studies of higher quality and longitudinal design are needed.
... As shown in Supp. 4, the funnel plot of standard error by Hedges' g was slightly asymmetric, indicating that there could be a minor publication bias, due either to our inability to identify studies with non-significant findings or researchers failing to report non-significant findings [32]. We ran the Tweedie's Trim and Fill test by imputing missing studies and recalculating the effect size. ...
Purpose of ReviewHigher plasma proprotein convertase subtilisin/kexin type 9 (PCSK9) concentration has been associated with a higher risk of atherosclerotic cardiovascular disease (ASCVD). Animal and human studies have examined the relationship between 24-h activity cycles (24-HAC) and PCSK9, but conflicting results exist. Therefore, this review aimed to examine the relationship between 24-HAC and plasma PCSK9 concentration in animals and humans.Three databases (PubMed, CINAHL, and Web of Science) were searched for eligible articles. Descriptive data were summarized using network meta-analysis. The effect size was estimated using pairwise meta-analysis.Recent FindingsThe interventions designed to increase moderate to vigorous physical activities (MVPA) did not significantly change plasma PCSK9 concentration (Hedges’ g = 0.137; p = 0.337). However, the effect was influenced by statin therapy and intervention delivery mode. Specifically, physical activity interventions in conjunction with statin therapy significantly increased plasma PCSK9 concentration (Hedges’ g = 0.275; p = 0.007). Supervised exercise training significantly increased plasma PCSK9 concentration (Hedges’ g = 0.630; p = 0.001), but physical activity counseling did not (p = 0.845).SummaryThe effects of MVPA on plasma PCSK9 may be moderated by statin therapy, intervention delivery mode, or other potential unknown mechanistic factors. Thus, caution should be taken when using plasma PCSK9 as an outcome indicator for physical activity interventions aimed at decreasing the risk of ASCVD.
Graphical abstract
... In systematic reviews the risk of publication bias needs to be assessed. Studies reporting higher effect sizes are more often published [60], which increases publication bias. This is because systematic reviews and meta-analyses only including these published studies may conclude that a false-positive relationship exists. ...
Introduction
It is unknown whether male body dissatisfaction is related to anxiety and depression. This study investigates whether there is an association between body dissatisfaction and self-reported anxiety and/or depression in otherwise healthy adult males.
Method
A systematic review was conducted using Preferred Reporting Items for Systematic Reviews and Meta Analyses as the reporting guideline. Four databases including CINAHL complete, Health Source: Nursing/Academic Edition, MEDLINE and PsycINFO were searched for observational studies with a correlational design. Studies were appraised using the Appraisal tool for Cross-Sectional Studies to measure quality and risk of bias. Data were extracted from studies to analyse and synthesise findings using content analysis and random effects meta-analyses in male body dissatisfaction and anxiety, depression, and both anxiety and depression.
Results
Twenty-three cross-sectional studies were included in the review. Nineteen studies found positive correlations between male body dissatisfaction and anxiety and/or depression. Meta-analyses of Pearson’s correlation coefficients found statistically significant associations with body satisfaction for anxiety 0.40 (95% CI 0.28 to 0.51) depression 0.34 (95% CI 0.22 to 0.45) and both anxiety and depression outcomes 0.47 (95% CI 0.33 to 0.59). The quality appraisal found study samples were homogeneous being mostly ascertained through academic institutions where participants were predominantly young, Caucasian and with relatively high educational attainment. Measures of body satisfaction focused predominantly on muscularity and thinness.
Discussion
This study provides the first pooled estimates of the correlation between body dissatisfaction and anxiety and depression in men. Findings need to be interpreted with respect to the samples and outcomes of the included studies. It is recommended that future research should increase the diversity of men in studies. Studies should measure a wider range of body dissatisfaction types found in men.
Conclusion
The findings demonstrate that an association between male body dissatisfaction and anxiety and depression is likely to exist. Future research should address the temporal relationship between body dissatisfaction and anxiety and depression.
... After screening the titles and abstracts, and following the examination of the full papers, 76 studies met all aforementioned inclusion criteria and were retained for analysis (see Figure 1 for procedure details). Based on the Rosenthal's suggestions for computing the fail-safe n, it was found that the total Z value was -1.181 and the number of missing studies we would need to retrieve and incorporate to result in a non-significant p-value was 147 studies (see also Borenstein, Hedges, Higgins, & Rothstein, 2009). ...
Treatment dropout is one of the most crucial issues that a therapist has to face on a daily basis. The negative effects of premature termination impact the client who is usually found to demonstrate poorer treatment outcomes. This meta-analysis reviewed and systematically examined dropout effects of Acceptance and Commitment Therapy (ACT) as compared to other active treatments. The goals of this study were to compare treatment dropout rates and dropout reasons, examine the influence of demographic variables and identify possible therapy moderators associated with dropout.
The current meta-analysis reviewed 76 studies of ACT reporting dropout rates for various psychological and health-related conditions.
Across reviewed studies (N = 76), the overall weighted mean dropout rate was 17.95% (ACT = 17.35% vs. comparison conditions = 18.62%). Type of disorder, recruitment setting and therapists’ experience level were significant moderators of dropout. The most frequently reported reasons for dropout from ACT were lost contact, personal and transportation difficulties, whereas for comparative treatments they were lost contact, therapy factors and time demands.
Given that most moderators of influence are not amenable to direct changes by clinicians, mediation variables should also be explored. Overall, results suggest that ACT appears to present some benefits in dropout rates for specific disorders, settings and therapists.
There was no difference in dropout rate between ACT and control conditions (17.35% vs.18.62%). Significant moderators were client disorder, therapists’ experience level and recruitment and setting.
Comparison condition frequently reported therapy related dropout factors, suggesting that ACT may be a more acceptable option.
There was no difference in dropout rate between ACT and control conditions (17.35% vs.18.62%). Significant moderators were client disorder, therapists’ experience level and recruitment and setting.
Comparison condition frequently reported therapy related dropout factors, suggesting that ACT may be a more acceptable option.
... Heterogeneity was assessed using I 2 statistic (with 95% CI) [12] where I 2 values of 25, 50, and 75% may be considered as low, moderate, and high heterogeneity, respectively. The possibility of publication bias was assessed by a funnel plot and Egger's regression asymmetry test [13]. Statistical analysis was performed using STATA software (version 13.0). ...
Background
The role of intravenous hydration at the time of primary percutaneous intervention (PCI) for ST-segment elevation myocardial infarction (STEMI) remains unclear. Guidelines are vague, supported by low level evidence, and hydration is used less often than other clinical settings.To perform a systematic review and meta-analysis of all randomized controlled trials assessing intravenous hydration compared with non-hydration for prevention of contrast induced nephropathy (CIN) and In-hospital mortality in patients with STEMI undergoing primary PCI.
Methods
Medline, EMBASE and the Cochrane Register were searched to September 2018. Included studies reported the incidence of CIN, In-hospital mortality, requirement for dialysis and heart failure. Relative risks with 95% confidence intervals (CIs) for individual trials were pooled using a random effects model.
Results
Three moderate quality trials were identified including 1074 patients. Overall, compared with no hydration, intravenous hydration significantly reduced the incidence of CIN by 42% (RR 0.58; 95% CI: 0.45 to 0.74, p < 0.001). The estimated effects upon all-cause mortality (RR 0.56; 95% CI: 0.30 to 1.02, p = 0.057) and the requirement for dialysis (RR 0.52, 95% CI 0.14–1.88, p = 0.462) were not statistically significant. The outcome of heart failure was not consistently reported.
Conclusions
Intravenous hydration likely reduces the incidence of CIN in patients with STEMI undergoing primary PCI. However, for key clinical outcomes such as mortality, heart failure and dialysis the effect estimates were imprecise. Further high quality studies are needed to clarify the appropriate volume of fluid and effects on outcomes.
Electronic supplementary material
The online version of this article (10.1186/s12872-019-1054-y) contains supplementary material, which is available to authorized users.
... The publication bias was visually examined by a funnel plot and statistically evaluated by Egger's regression asymmetry test [48,49]. ...
Introduction
Two previous meta‐analyses evaluated the risk of cataracts associated with statins, but did not include relevant studies suggesting a cataratogenic effect.
Aims
The aim of this systematic review and meta‐analysis of observational studies is to evaluate such association considering the latest published evidence.
Methods
A literature search was conducted to identify observational, comparative studies evaluating the risk of developing cataracts in patients treated with statins. A meta‐analysis was performed to estimate Odds ratios (ORs). Results were stratified according to the following studies’ subgroups: design, methodological quality, method of diagnosis of cataract, patients’ age and median follow‐up. Meta‐regressions evaluated the influence of the following risk factors: smoking, hypertension, corticosteroids, selective serotonin reuptake inhibitors (SSRI), diabetes mellitus and cardiovascular disease.
Results
Twenty one studies were included. Treatment with statins was associated with an increased risk of cataracts [OR 1.11 (95% CI 1.02–1.21); p=0.017; I²=97.5%]. This risk remained statistically significant among case‐controls, good methodological quality studies, studies with length of follow‐up ≥5 years and those which outcome was cataract surgery. Between‐studies heterogeneity was high among all risk estimates. Meta‐regressions identified an inverse relationship between the risk of cataracts and the proportion of diabetic patients in the studies.
Conclusions
The results point out an increased risk of cataract development with statins. However, since the magnitude of the effect is low and between‐studies heterogeneity is high, the extent in which these results have impact on the benefit/risk ratio of statins is difficult to ascertain due to the uncertainty of the findings.
This article is protected by copyright. All rights reserved.
OBJECTIVE
Several case series have investigated the use of laser interstitial thermal therapy (LITT) to treat cavernous malformations (CMs), for either seizure control or reduction of neurological symptoms and future hemorrhage risk. However, pooled outcomes are largely unknown. The authors aimed to quantify posttreatment seizure freedom, symptomatic progression or hemorrhage, perioperative complications, and imaging outcomes from the available literature.
METHODS
This study was a PRISMA-compliant systematic review and individual patient-level data meta-analysis of studies reporting LITT ablation of CMs. For patients with epilepsy, the pooled Engel seizure freedom rate was calculated. The rate of symptomatic progression or hemorrhage was calculated for all patients. Fixed-effects logistic regression models were used to test for predictors of seizure freedom and postoperative complications. Linear regression models were used to obtain pooled estimates of the percent CM volume ablated.
RESULTS
A total of 39 patients (28 with epilepsy) underwent LITT for the treatment of 45 CMs (37 cortical, 8 subcortical) at six centers. Among patients with epilepsy, 88.0% (95% CI 68.7%–96.1%) were seizure free at the last follow-up (median 30.0 months, range 12.0–49.0 months). Six patients (15.4%) experienced immediate postoperative neurological deficits. No perioperative hemorrhage was reported, and no patients experienced subsequent hemorrhage or symptomatic progression during follow-up (median 26.0 months, range 2.0–53.0 months). There was no difference in the odds of seizure freedom or adverse events based on preoperative characteristics. Nonepileptogenic CMs (mean volume 2.5 cm ³ ) were significantly larger than epileptogenic CMs (mean volume 0.8 cm ³ ; p = 0.002). LITT was associated with a mean CM volume reduction of 73.7% (95% CI 64.1%–83.2%, p < 0.0001) for epileptogenic CMs and 53.8% (95% CI 14.2%–93.3%, p < 0.023) for nonepileptogenic CMs (p = 0.14).
CONCLUSIONS
LITT is a promising therapy for CMs with the goal of seizure control or prevention of symptomatic progression or hemorrhage. While there is a notable risk of immediate postablation neurological deficit, most were transient and nondisabling, and this risk must be weighed against that of continued observation or open resection. Considering the limited number of studies, small number of patients, and limited follow-up time available, additional experience and research with larger patient cohorts and longer-term follow-up will be necessary to validate these findings.
Augmented Reality (AR) has been continuously adopted in K-12 settings, showing its beneficial impact. Despite numerous studies highlighting the benefit of AR that can enhance students’ motivation, no meta-analysis providing an in-depth look into AR’s impact on students’ motivation has been conducted, particularly in K-12 settings. In this meta-analysis, we meta-analyzed 45 experimental studies using AR in K-12 settings from 2010 to 2022, guided by the Preferred Reporting Items for Systematic Reviews and Meta-Analysis procedure. We also conducted a moderator analysis considering diverse instructional considerations and study features, to offer a more focused and comprehensive understanding of AR’s effect on K-12 students’ motivation. The results showed a large effect of AR on enhancing K-12 students’ motivation (g = 0.803). Furthermore, we found that marker-based AR and collaborative learning significantly promoted K-12 students’ motivation, compared to location-based AR and non-collaborative learning experiences. The results indicated AR in K-12 settings needs to be carefully designed, considering how it is integrated within pedagogical practice. The implications and future research direction for researchers, educational practitioners, and AR developers are also discussed.
Since the first quarter of 2019, significant research efforts have been dedicated to curtail the spread of COVID-19. This study aimed to complement existing research by synthesizing Cronbach’s alpha coefficients and generalizing the Fear of COVID-19 Scale, with the goal of reducing the pandemic’s impact. Through a systematic literature search in electronic databases from 2019 to February 2021, we identified 2,753 works published in various sources, including journals, conference proceedings, books, and book chapters. Out of these, only 26 studies provided Cronbach’s alpha coefficients and were included in the meta-analysis. Employing a random-effects model, we analyzed the data and found that the Fear of COVID-19 Scale exhibited excellent internal consistency [α = 0.87 (95% CI 0.86–0.88)]. However, there was significant heterogeneity among the included studies. Despite this, the Fear of COVID-19 Scale demonstrated good internal consistency reliability. As the fight against COVID-19 continues, we encourage future psychometric studies of the Fear of COVID-19 Scale to report important characteristics of participants and details of item scores Keywords: Cronbach’s alpha, fear of Covid-19 scale, meta-analysis, reliability generalization, random effect
Publication bias refers to a systematic deviation from the truth in the results of a meta-analysis due to the higher likelihood for published studies to be included in meta-analyses than unpublished studies. Publication bias can lead to misleading recommendations for decision- and policy-making. In this education review, we introduce, explain, and provide solutions to the pervasive misuses and misinterpretations of publication bias that afflict evidence syntheses in sport and exercise medicine, with a focus on the commonly used funnel-plot based methods. Publication bias is more routinely assessed by visually inspecting funnel plot asymmetry, although it has been consistently deemed unreliable, leading to the development of statistical tests to assess publication bias. However, most statistical tests of publication bias (i) cannot rule out alternative explanations for funnel plot asymmetry (e.g., between-study heterogeneity, choice of metric, chance), and (ii) are grossly underpowered, even when using an arbitrary minimum threshold of ≥10 studies. We performed a cross-sectional, meta-research investigation of how publication bias was assessed in systematic reviews with meta-analysis published in the top two sport and exercise medicine journals throughout 2021. This analysis highlights that publication bias is frequently misused and misinterpreted, even in top tier journals. Due to conceptual and methodological problems when assessing and interpreting publication bias, preventive strategies (e.g., pre-registration, registered reports, disclosing protocol deviations, and reporting all study findings regardless of direction or magnitude) offer the best and most efficient solution to mitigate the misuse and misinterpretation of publication bias. Because true publication bias is very difficult to determine, we recommend that future publications use the term “risk of publication bias”.
Objectives:
Elder suicide is a serious concern in many countries, including South Korea. Various policies and programs to prevent elder suicide are essential; however, further understanding of this phenomenon is necessary. The current study, therefore, developed a model for understanding the underlying mechanism of suicidal ideation in older adults in South Korea. The model was based on Andersen's theory (2021), which explains the path from social relationships to mental health.
Methods:
This study was conducted utilizing meta-analytic structural equation modeling in accordance with a pooled correlation matrix. We used data from 93 existing studies systematically identified in nine academic databases.
Results:
The fit statistics show that our model fits the data well. The results demonstrated that suicidal ideation was directly affected by abuse, depression, and self-esteem but not by family relationships. Depression significantly mediated the relationship between abuse and suicidal ideation and between family relationships and suicidal ideation.
Conclusion:
Social relationships play an important role in determining mental health among Korean older adults, consistent with Andersen's theory. Prevention of elder abuse and depression is essential in preventing suicide among older adults in South Korea.
Meta-analysis is a popular approach in the psychological sciences for synthesizing data across studies. However, the credibility of meta-analysis outcomes depends on the evidential value of studies included in the body of evidence used for data synthesis. One important consideration for determining a study’s evidential value is the statistical power of the study’s design/statistical test combination for detecting hypothetical effect sizes of interest. Studies with a design/test combination that cannot reliably detect a wide range of effect sizes are more susceptible to questionable research practices and exaggerated effect sizes. Therefore, determining the statistical power for design/test combinations for studies included in meta-analyses can help researchers make decisions regarding confidence in the body of evidence. Because the one true population effect size is unknown when hypothesis testing, an alternative approach is to determine statistical power for a range of hypothetical effect sizes. This tutorial introduces the metameta R package and web app, which facilitates the straightforward calculation and visualization of study-level statistical power in meta-analyses for a range of hypothetical effect sizes. Readers will be shown how to reanalyze data using information typically presented in meta-analysis forest plots or tables and how to integrate the metameta package when reporting novel meta-analyses. A step-by-step companion screencast video tutorial is also provided to assist readers using the R package.
This meta-analysis assesses the predictive validity of the Graduate Record Examination (GRE) across outcome variables, including grade point average, for graduate students. In addition to aggregate effects, this paper also assessed changes in observed effects over time as related to increasing diversity in the graduate student population and as a function of gender and racial/ethnic composition of study samples. Framed using a lens of critical whiteness, this analysis examined n = 1,659 individual effects across k = 201 studies. Overall, 62.3% of reported effects were nonsignificant (i.e. no predictive value of GRE scores on student outcomes). Further, the magnitude of observed predictive relationships decreased significantly over time. The aggregate mean effect across all studies and outcomes was small, significant, and positive: GRE score predicted 3.24% of variance across measured outcomes, 4% of variance in overall GPA, and 2.56% of variance in first-year graduate GPA. Sample composition effects by race/ethnicity were notable under some conditions, but nonsignificant, with increasing proportions of people of Color within a study sample associated with poorer predictive validity for GPA. Likewise, the magnitude of negative effects where lower GRE scores predicted stronger student outcomes showed increasing trends from 0.16% of variance for all-white samples to 7.3% for samples comprised entirely of people of Color.
Reporting standardized effects in randomized treatment studies aids interpretation and facilitates future meta-analyses and policy considerations. However, when outcome data are missing, achieving an unbiased, accurate estimate of the standardized average treatment effect, sATE, can pose challenges even for those with general knowledge of missing data handling, given that the sATE is a ratio of a mean difference to a (within-group) standard deviation. Under both homogeneity and heterogeneity of variance, a Monte Carlo simulation study was conducted to compare missing data handling strategies in terms of bias and accuracy in the sATE, under specific missingness patterns plausible for randomized pretest posttest studies. Within two broad missing data handling approaches, maximum likelihood and multiple imputation, modeling choices were thoroughly investigated including the analysis model, variance estimator, imputation algorithm, and method of pooling results across imputed datasets. Results demonstrated that although the sATE can be estimated with little bias using either maximum likelihood or multiple imputation, particular attention should be paid to the model and variance estimator, especially at smaller sample sizes (i.e., N = 50). Differences in accuracy were driven by differences in bias. To improve estimation of the sATE in practice, recommendations and a software demonstration are provided. Moreover, a pedagogical explanation of the causes of bias, described separately for the numerator and denominator of the sATE is provided, demonstrating visually how and why bias occurs with certain methods.
Meta-analyses are essential for cumulative science, but their validity can be compromised by publication bias. To mitigate the impact of publication bias, one may apply publication-bias-adjustment techniques such as precision-effect test and precision-effect estimate with standard errors (PET-PEESE) and selection models. These methods, implemented in JASP and R, allow researchers without programming experience to conduct state-of-the-art publication-bias-adjusted meta-analysis. In this tutorial, we demonstrate how to conduct a publication-bias-adjusted meta-analysis in JASP and R and interpret the results. First, we explain two frequentist bias-correction methods: PET-PEESE and selection models. Second, we introduce robust Bayesian meta-analysis, a Bayesian approach that simultaneously considers both PET-PEESE and selection models. We illustrate the methodology on an example data set, provide an instructional video ( https://bit.ly/pubbias ) and an R-markdown script ( https://osf.io/uhaew/ ), and discuss the interpretation of the results. Finally, we include concrete guidance on reporting the meta-analytic results in an academic article.
Replication is central to scientific progress. Because of widely reported replication failures, replication has received increased attention in psychology, sociology, education, management, and related fields in recent years. Replication studies have generally been assessed dichotomously, designated either a “success” or “failure” based entirely on the outcome of a null hypothesis significance test (i.e., p < .05 or p > .05, respectively). However, alternative definitions of success depend on researchers’ goals for the replication. Previous work on alternative definitions for success has focused on the analysis phase of replication. However, the design of the replication is also important, as emphasized with the adage, “an ounce of prevention is better than a pound of cure.” One critical component of design often ignored or oversimplified in replication studies is sample size planning, indeed, the details here are crucial. Sample size planning for replication studies should correspond to the method by which success will be evaluated. Researchers have received little guidance, some of which is misguided, on sample size planning for replication goals other than the aforementioned dichotomous null hypothesis significance testing approach. In this article, we describe four different replication goals. Then, we formalize sample size planning methods for each of the four goals. This article aims to provide clarity on the procedures for sample size planning for each goal, with examples and syntax provided to show how each procedure can be used in practice.
In recent years, the problem of mobile phone addiction (MPA) has become increasingly serious among mainland Chinese adolescents. Studies have found that self-esteem may be related to MPA, but the conclusions are inconsistent. Consequently, this meta-analysis aims to explore the real relationship between self-esteem and MPA, and analyze the moderator variables. The relevant studies used in meta-analysis were obtained by searching China National Knowledge Infrastructure (CNKI), Wan Fang Data, Chongqing VIP Information Co., Ltd. (VIP), PubMed, Web of Science, Scopus, Medline and Embase. Then articles were screened and coded, and statistical analysis was carried out by Stata 16.0 software. A total of 45,765 participants from 64 articles were included in the research. Meta-analysis showed that there was a moderate negative correlation between self-esteem and MPA( r = −.25, 95% CI = −.29, −.21). Subgroup analysis and meta-regression analysis showed that the age and publication time can significantly moderate the relationship between self-esteem and MPA, but MPA measurement instrument, gender, region and publication type have no significant moderating effect. The current meta-analysis provided solid evidence that self-esteem was negatively correlated with MPA. Longitudinal studies are needed to clarify the causality between them, so as to make more specific practice and policy recommendations.
Cardiac resynchronization therapy (CRT) may improve not only impaired left ventricular contractility but can also induce reverse remodeling of native conduction system. Measurement of intrinsic QRS complex width during follow-up is the simplest method to assess reverse electrical remodeling (RER). We aimed to provide a literature review and meta-analysis on incidence and impact of RER and its association with mechanical remodeling. A systematic review and random-effect meta-analysis of studies reporting data on RER was performed. A total of 16 studies were included in this meta-analysis with 930 patients undergoing CRT (mean age 64.0 years, 64.1% males). The weighted mean incidence of RER was 42%. Reverse mechanical remodeling assessed by echocardiography was more frequently observed in patients with RER compared to patients without RER (75.7% vs. 46.6%; odds ratio [OR] 3.7, 95% confidence interval [CI] 2.24–6.09, p < 0.01). Mechanical responders had a mean iQRS shortening of 7.7 ms, while mechanical non-responders experienced a mean widening of iQRS by 5.2 ms (p < 0.01). Clinical improvement was more frequent in patients with RER vs. patients without RER (82.9% vs. 49.0%; OR 5.26; 95% CI 2.92–9.48; p < 0.01). No significant difference in all‐cause mortality between patients with and without RER was found. Mean difference between baseline intrinsic QRS and post-implantation paced QRS was significant in patients with later RER (21.2 ms, 95% CI 9.4–32.9, p < 0.01), but not in patients without RER (6.6 ms, 95% CI -2.2–15.4, p = 0.14). Gender, initial left bundle block morphology and heart failure etiology were found not to be predictive for RER. Our meta-analysis demonstrates that shortening of iQRS duration is a common finding during follow-up of patients undergoing CRT and is associated with mechanical reverse remodeling and clinical improvement. Clinical Trial Registration: Prospero Database-CRD42021253336.
Background
Glucocorticoids have been suggested as a potential therapy in refractory obstetric antiphospholipid syndrome (oAPS). Our aims were to describe a cohort of patients with oAPS treated with low-dose glucocorticoids and to perform a systematic review and meta-analysis evaluating the effects of additional glucocorticoids on the pregnancy outcomes in oAPS patients.
Methods
Retrospective study that included 11 women diagnosed with primary antiphospholipid syndrome. The meta-analysis was conducted by fitting random effects models and was checked for heterogeneity.
Results
All women had suffered from early pregnancy losses and two also had a history of fetal deaths. We studied 47 pregnancies that resulted in 32 abortions (68.1%) and 3 fetal deaths (6.4%). Twenty-six pregnancies were under treatment, mainly LDA and LMWH. Low-dose glucocorticoids were indicated in 13 pregnancies (always in association with LDA and LMWH). There was a decrease in pregnancy loss in those patients treated with LDA and LMWH. Treatment with glucocorticoids significantly increased the rate of successful pregnancy (38.5% abortions in treated vs 85.3% abortions in non-treated pregnancies; p=0.003). After multivariate GEE analysis, only glucocorticoids remained inversely associated with pregnancy loss (OR=0.157, (CI 0.025–0.968, p=0.046)). The meta-analysis showed that glucocorticoids tended to improve the frequency of successful pregnancy (OR= 0.509 (0.252–1.028), p=0.06). Three cases of gestational diabetes and one of preeclampsia were observed in our cohort. The meta-analysis, which mostly included studies using high-dose steroids, showed that glucocorticoids increased not only the frequency of preeclampsia and gestational diabetes, but also the rate of pre-term birth.
Conclusions
The efficacy of low-dose glucocorticoids in addition to the standard therapy in patients with refractory oAPS should be confirmed in well-designed clinical trials. However, high doses of steroids significantly increase the frequency of maternal and fetal morbidities, making their use strongly inadvisable.
Background:
Deprescribing, a relatively recent concept, has been proposed as a promising solution to the growing issues of polypharmacy and use of medications of questionable benefit among older adults. However, little is known about the health outcomes of deprescribing interventions.
Objective:
This paper presents the protocol of a study that aims to contribute to the knowledge on deprescribing by addressing two specific objectives: (1) describe the impact of deprescribing in adults ≥60 years on health outcomes or quality of life; and (2) determine the characteristics of effective interventions in deprescribing.
Methods:
Primary studies targeting three concepts (older adults, deprescribing, and health or quality of life outcomes) will be included in the review. The search will be performed using key international databases (MEDLINE, EMBASE, CINAHL, Ageline, PsycInfo), and a special effort will be made to identify gray literature. Two reviewers will independently screen the articles, extract the information, and evaluate the quality of the selected studies. If methodologically feasible, meta-analyses will be performed for groups of intervention studies reporting on deprescribing interventions for similar medications, used for similar or identical indications, and reporting on similar outcomes (eg, benzodiazepines used against insomnia and studies reporting on quality of sleep or quality of life). Alternatively, the results will be presented in bottom-line statements (objective 1) and a matrix outlining effective interventions (objective 2).
Results:
The knowledge synthesis may be limited by the availability of high-quality clinical trials on deprescribing and their outcomes in older adults. Additionally, analyses will likely be affected by studies on the deprescribing of different types of molecules within the same indication (eg, different pharmacological classes and medications to treat hypertension) and different measures of health and quality of life outcomes for the same indication. Nevertheless, we expect the review to identify which deprescribing interventions lead to improved health outcomes among seniors and which of their characteristics contribute to these outcomes.
Conclusions:
This systematic review will contribute to a better understanding of the health outcomes of deprescribing interventions among seniors.
Trial registration:
PROSPERO International Prospective Register of Systematic Reviews CRD42015020866; https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42015020866.
International registered report identifier (irrid):
PRR1-10.2196/25200.
Background and Aims
Hospital readmissions among COVID‐19 patients have increased the load on the healthcare systems and added more pressure to hospital capacity. This affects the ability to accommodate newly diagnosed COVID‐19 patients and other non‐COVID‐19 patients who require hospitalization. Therefore, this systematic review aims to understand the rates of and risk factors for hospital readmissions and all‐cause mortality among COVID‐19 patients who were hospitalized after being discharged following index hospitalization.
Methods
Our systematic review protocol is registered with the International Prospective Register of Systematic Reviews (PROSPERO) (CRD42021232324) and prepared in accordance with the Preferred Reporting Items for Systematic Reviews and Meta‐Analysis Protocols (PRISMA‐P) 2015 statement. We will search MEDLINE (Ovid), EMBASE (Ovid), MedRxiv, Web of Science (Science Citation Index), ProQuest Coronavirus research database, Cochrane Covid‐19 study register, and WHO COVID‐19: Global literature on coronavirus disease will be identified from December 31, 2019, to May 31, 2021. Two investigators will independently screen titles and abstracts and select studies reporting hospital readmissions among COVID‐19 patients. Further, data extraction and risk of bias assessment will be carried out separately by these independent reviewers. We will extract data on demographics, readmissions, all‐cause mortality, emergency department visits, comorbidities, and factors associated with hospitalization among COVID‐19 patients. Random‐effect meta‐analysis will be performed if homogeneous groups of studies are found. The combined evidence will be further stratified according to important background characteristics if the data allow.
Discussion
This systematic review will summarize the available epidemiological evidence regarding rates of hospital readmissions, comorbidities, and related factors among COVID‐19 patients who were readmitted after index hospitalization. A better understanding of the relationship between patient profiles and the rate of hospitalization will be helpful in the development of guidelines for patient management.
The role of the prison officer is complex and challenging. In order to discharge their duties effectively, prison officers require relevant and comprehensive training and education upon recruitment and throughout their working career. The following paper presents the findings of a scoping review of the published literature as it relates to the training and education of prison officers. Employing a descriptive-analytical approach, we stratified this literature into three overarching themes; namely entry-level training and education programs, emerging issues and developments in prison officer training, and specialist health and well-being training programs. Findings are discussed with reference to significant current trends in the literature and potential areas of future research and practice.
Due to the nature of listening, multiple media tools have been utilized in second language (L2) listening instruction for a long time. This chapter recruited the most recently published empirical studies in addition to the meta-analysis conducted in 2015 (Kang) and analyzed available evidence on the effects of different multiple media tools on L2 listening comprehension. The results revealed a medium-to-large effect of multiple media tools on listening comprehension in between-group designs (Cohen's d = .70), which was almost identical to the result observed five years ago. The effects of individual multiple media tools have also been statistically synthesized. Moderator analysis could help L2 educators and test developers make decisions on applying different multiple media tools in the fields of L2 instruction and assessment. Specifically, subtitles, captions, as well as self-regulated listening and slow speed were recommended to teachers and test developers as a means to improve learners' listening comprehension.
Despite the existence of a large body of literature on the topic of supply chain (SC) resilience, comprehensive empirical reviews of the antecedents and outcomes of resilience are limited. The purpose of this study is to develop a theoretical framework and carry out a meta-analysis of extant empirical studies to investigate the relationship between resilience, its antecedents and firm performance. The impact of three clusters of SC capabilities (organisational capability, SC flexibility, SC integration) on firm resilience (proactive, reactive or dynamic) is examined, and that of the impact of firm resilience on performance. We find that the overall impact of resilience on firm performance is strongly significant. However, in terms of financial performance, the correlation magnitude shows a weaker to moderate effect. In addition, for non-financial performance, the resilience impact is stronger. Furthermore, the analysis helps clarify some of the existing inconsistencies in the literature regarding the relationship between SC capabilities, firm
resilience and performance by highlighting the moderating role played by resilience operationalisation, industry affiliation and national culture. The study contributes to theory on resilience and assists practitioners in developing resilient strategies for organisations and SCs.
Polysomnographic studies have been conducted to explore nighttime sleep features in narcolepsy, but their relationship to narcolepsy is still imperfectly understood. We conducted a systematic review of the literature exploring polysomnographic differences between narcolepsy patients and healthy controls (HCs) in EMBASE, MEDLINE, All EBM databases, CINAHL, and PsycINFO. 108 studies were identified for this review, 105 of which were used for meta-analysis. Meta-analyses revealed significant reductions in sleep latency, sleep efficiency, slow wave sleep percentage, rapid eye movement sleep (REM) latency, cyclic alternating pattern (CAP) rate, and increases in total sleep time, wake time after sleep onset (WASO), awakening numbers (AWN) per hour, stage shift (SS) per hour, N1 percentage, apnea hypopnea index, and periodic limb movement index in narcolepsy patients compared with HCs. Furthermore, narcolepsy type 1 patients showed more disturbed nighttime sleep compared with narcolepsy type 2 patients. Children and adolescent narcolepsy patients show increased WASO, AWN, and SS compared with adult patients. Macro- and micro-structurally, our study suggests that narcolepsy patients have poor nighttime sleep. Sex, age, body mass index, disease duration, disease type, medication status, and adaptation night are demographic, clinical and methodological factors that contribute to heterogeneity between studies.
This study reviewed and synthesized existing research to examine the association of parent–child experiences in childhood with two types of adult insecure attachments styles: anxiety‐related attachment (ANA) and avoidance‐related attachment (AVA). Correlates of adult insecure attachment styles were systematically reviewed and quantitatively synthesized using meta‐analytic methods. Overall, 213 and 177 correlates with ANA and AVA were identified from 56 studies, with these factors further categorized into four thematic domains: perceived attachment with parents, perceived parenting style, perceived relationship with parents, and recalled childhood adversity. Children's attachment patterns with their parents were strongly associated with their pattern of adult attachment. Codependent relationships with parents, childhood neglect, and childhood psychological abuse were also significantly associated with both ANA and AVA. Authoritarian and authoritative parenting styles showed the strongest positive and negative associations with ANA and AVA, respectively. Our findings revealed the importance of early parenting for children's lifelong health and developmental outcomes.
Medical device-associated infections (MDAI) are a critical problem due to the increasing usage of medical devices in the aging population. The inhibition of biofilm formation through the use of probiotics has received attention from the medical field in the last years. However, this sparse knowledge has not been properly reviewed, so that successful strategies for biofilm management can be developed. This study aims to summarize the relevant literature about the effect of probiotics and their metabolites on biofilm formation in medical devices using a PRISMA-oriented (Preferred Reporting Items for Systematic reviews and Meta-Analyses) systematic search and meta-analysis. This approach revealed that the use of probiotics and their products is a promising strategy to hinder biofilm growth by a broad spectrum of pathogenic microorganisms. The meta-analysis showed a pooled effect estimate for the proportion of biofilm reduction of 70% for biosurfactants, 76% for cell-free supernatants (CFS), 77% for probiotic cells and 88% for exopolysaccharides (EPS). This review also highlights the need to properly analyze and report data, as well as the importance of standardizing the in vitro culture conditions to facilitate the comparison between studies. This is essential to increase the predictive value of the studies and translate their findings into clinical applications.
Background: Necrotizing enterocolitis (NEC) is the leading cause of morbidity and mortality from gastrointestinal disease in very and extremely preterm infants. Stem cell therapy has shown some promising protective effects in animal models of intestinal injury, including NEC, but no systematic review has yet evaluated the preclinical evidence of stem cell therapy for NEC prevention or treatment.
Methods: PubMed and EMBASE databases were searched for studies using an animal model of NEC with stem cells or their products. Risk of bias was assessed using the SYRCLE tool. A random-effects model was used to pool odds ratios (OR) and 95% confidence interval (CI).
Results: We screened 953 studies, of which 9 (8 rat, 1 mouse model) met the inclusion criteria. All animal models induced NEC by a combination of hypothermia, hypoxia and formula feeding. Risk of bias was evaluated as unclear on most items for all studies included. Meta-analysis found that both mesenchymal and neural stem cells and stem cell-derived exosomes reduced the incidence of all NEC (OR 0.22, 95% CI 0.16-0.32, k=16), grade 2 NEC (OR 0.41, 95% CI 0.24-0.70, k=16), and grade 3-4 NEC (OR 0.28, 95% CI 0.19-0.42, k=16). K represents the number of independent effect sizes included in each meta-analysis. The effect of the exosomes was similar to that of the stem cells. Stem cells and exosomes also improved 4-day survival (OR 2.89 95% CI 2.07-4.04, k=9), and 7-day survival (OR 3.96 95% CI 2.39-6.55, k=5) after experimental NEC. Meta-analysis also found that stem cells reduced other indicators of intestinal injury.
Conclusion: The data from this meta-analysis suggest that both stem cells and stem cell-derived exosomes prevented NEC in rodent experimental models. However, unclear risk of bias and incomplete reporting underline that poor reporting standards are common and hamper the reliable interpretation of preclinical evidence for stem cell therapy for NEC.
Low productivity and climate change require climate-smart agriculture (CSA) for sub-Saharan Africa (SSA), through (i) sustainably increasing crop productivity, (ii) enhancing the resilience of agricultural systems, and (iii) offsetting greenhouse gas emissions. We conducted a meta-analysis on experimental data to evaluate the contributions of combining organic and mineral nitrogen (N) applications to the three pillars of CSA for maize (Zea mays). Linear mixed effect modeling was carried out for; (i) grain productivity and agronomic efficiency of N (AE) inputs, (ii) inter-seasonal yield variability, and (iii) changes in soil organic carbon (SOC) content, while accounting for the quality of organic amendments and total N rates. Results showed that combined application of mineral and organic fertilizers leads to greater responses in productivity and AE as compared to sole applications when more than 100 kg N ha⁻¹ is used with high-quality organic matter. For yield variability and SOC, no significant interactions were found when combining mineral and organic fertilizers. The variability of maize yields in soils amended with high-quality organic matter, except manure, was equal or smaller than for sole mineral fertilizer. Increases of SOC were only significant for organic inputs, and more pronounced for high-quality resources. For example, at a total N rate of 150 kg N ha⁻¹ season⁻¹, combining mineral fertilizer with the highest quality organic resources (50:50) increased AE by 20% and reduced SOC losses by 18% over 7 growing seasons as compared to sole mineral fertilizer. We conclude that combining organic and mineral N fertilizers can have significant positive effects on productivity and AE, but only improves the other two CSA pillars yield variability and SOC depending on organic resource input and quality. The findings of our meta-analysis help to tailor a climate smart integrated soil fertility management in SSA.
Spatial skills significantly predict educational and occupational achievements in science, technology, engineering, and mathematics (STEM). As early interventions for young children are usually more effective than interventions that come later in life, the present meta-analysis systematically included 20 spatial intervention studies (2009–2020) with children aged 0–8 years to provide an up-to-date account of the malleability of spatial skills in infancy and early childhood. Our results revealed that the average effect size (Hedges's g) for training relative to control was 0.96 (SE = 0.10) using random effects analysis. We analyzed the effects of several moderators, including the type of study design, sex, age, outcome category (i.e., type of spatial skills), research setting (e.g., lab vs. classroom), and type of training. Study design, sex, and outcome category were found to moderate the training effects. The results suggest that diverse training strategies or programs including hands-on exploration, visual prompts, and gestural spatial training significantly foster young children's spatial skills. Implications for research, policy, and practice are also discussed.
Polysomnographic studies conducted to explore sleep changes in idiopathic rapid eye movement sleep behavior disorder (iRBD) have not established clear relationships between sleep disturbances and iRBD. To explore the polysomnographic differences between iRBD patients and healthy controls and their associated factors, an electronic literature search was conducted in EMBASE, MEDLINE, All EBM databases, CINAHL, and PsycINFO inception to December 2019. 34 studies were identified for systematic review, 33 of which were used for meta-analysis. Meta-analyses revealed significant reductions in total sleep time (SMD =-0.212, 95%CI: -0.378 to -0.046), sleep efficiency (SMD =-0.194, 95%CI: -0.369 to -0.018), apnea hypopnea index (SMD =-0.440, 95%CI: -0.780 to -0.101), and increases in sleep latency (SMD =0.340, 95%CI: 0.074 to 0.606), and slow wave sleep (SMD =0.294, 95%CI: 0.064 to 0.523) in iRBD patients compared with controls. Furthermore, electroencephalogram frequency components during REM sleep were altered in iRBD patients compared with controls; however, the specific changes could not be determined. Our findings suggest that polysomnographic sleep is abnormal in iRBD patients. Further studies are needed on underlying mechanisms and associations with neurodegenerative diseases.
Polysomnographic studies have been conducted to explore sleep changes in Parkinson's disease (PD), but the relationships between sleep disturbances and PD are imperfectly understood. We conducted a systematic review of the literature exploring polysomnographic differences between PD patients and controls in EMBASE, MEDLINE, All EBM databases, CINAHL, and PsycIFNO. 67 studies were identified for systematic review, 63 of which were used for meta-analysis. Meta-analyses revealed significant reductions in total sleep time, sleep efficiency, N2 percentage, slow wave sleep, rapid eye movement sleep (REM) percentage, and increases in wake time after sleep onset, N1 percentage, REM latency, apnea hypopnea index, and periodic limb movement index in PD patients compared with controls. There were no remarkable differences in sleep continuity or sleep architecture between PD patients with and without REM sleep behavior disorder (RBD). Our study suggests that PD patients have poor sleep quality and quantity. Sex, age, disease duration, presence of RBD, medication status, cognitive impairment, and adaptation night are factors that contributed to heterogeneity between studies.
Behavioral inhibition (BI) is a risk factor for anxiety. However, the estimates of the strength of this association vary widely. In addition, while BI is a strong predictor of social anxiety disorder (SAD), its association with other anxiety disorders is unclear. The current study sought to establish the relationship between BI and anxiety and to quantify this association for a range of anxiety disorders. We searched PsycInfo, PubMed and Embase for articles published before May 18th, 2019 using search terms for BI, anxiety and prospective study design. We selected articles which assessed the prospective relationship between BI in childhood and anxiety. Using random-effects meta-analysis with robust variance estimation, which allowed for the inclusion of multiple follow-ups of the same sample, we established the association between BI and any anxiety. We also explored the association between BI and individual anxiety disorders. Data from 27 studies consisting of 35 follow-ups of 20 unique samples indicated that BI prospectively increases the odds of anxiety (OR = 2.80, 95% CI 2.03 to 3.86, p < 0.001). There was also a positive association between BI and all individual anxiety disorders, with effect sizes ranging from small in the case of specific phobia (OR = 1.49, 95% CI 1.03 to 2.14, p = 0.03) to large in the case of SAD (OR = 5.84, 95% CI 3.38 to 10.09, p < 0.001). BI in early childhood is a strong risk factor for anxiety. Targeting BI may help reduce the number of children who will develop anxiety disorders.
Empirical studies demonstrate the difference between the willingness-to-pay for a good and the willingness-to-accept giving it away, known as the WTP-WTA disparity. Understanding this effect helps intangible goods to be properly valued or the plausibility of suggested explanations to be adequately judged. We verified the existence of a publication bias in the literature (are studies finding larger disparities more likely to be published?) using 102 studies published over the period 1980–2018. We analysed how the estimate of disparity is associated with the estimation uncertainty using rank correlation and linear/quantile/panel/meta regression; this multiplicity of approaches was used to check the robustness of the results against confounding, skewness, hierarchical data, and possible changes over time. With few exceptions, a bias-suggesting positive association is present (yet decreases over time). Our analysis suggests that the mean disparity estimates may be overestimated, by approximately 12% (3% in more recent studies). Disparity is greater for non-market goods (confirming previous findings) and when the same respondents valued both WTP and WTA. Authors and editors should not withhold publication simply because the results are not regarded as sufficiently controversial (and it seems this problem has been largely overcome). When performing meta-analysis, the latest studies should also be included.
Purpose:
The purpose of this study was to evaluate the effects of reminiscence therapy on depressive symptoms in older adults with dementia using a systematic review and meta-analysis.
Methods:
Randomized controlled trials (RCTs) published from January 2000 to January 2018 were searched through Research Information Sharing Service (RISS), Korean Studies Information Service System (KISS), Korean Medical Database (KMbase), KoreaMed, PubMed, Cochrane Library, Cumulative Index to Nursing and Allied Health Literature (CINAHL), and Ovid MEDLINE. Two researchers independently performed the search, selection, and coding. Comprehensive Meta-Analysis 3.0 was used for meta-analysis, and Review Manager program 5.3 was used for quality assessment.
Results:
Out of the 1,250 retrieved articles, 22 RCTs were selected for analysis. The overall effect size of reminiscence therapy for mitigating depressive symptoms in older adults with dementia was -0.62 (95% Cl: -0.92 to -0.31). The effect size was greater in older adults under 80, those with less disease severity, and those for whom the therapy session lasted less than 40 minutes.
Conclusion:
Reminiscence therapy is an effective non-pharmacological therapy to improve depressive symptoms in older adults with dementia. Because its effectiveness is also influenced by age, disease severity, and application method, it is necessary to consider treatment designs based on individual characteristics as well as methodological approaches.
Background:
Patients with undiagnosed hypothyroidism are not treated for the disease and are at high risk of developing serious complications, with major impact on public health. There is a need to systematically review the available evidence on this topic.
Objective:
To identify the prevalence of undiagnosed hypothyroidism in Europe.
Methods:
A systematic review of the literature (Medline, EMBASE, and Cochrane Central) was performed to identify epidemiological studies on the prevalence of undiagnosed hypothyroidism among European populations published between January 2008 and April 2018. The Newcastle-Ottawa Scale was used to assess the methodological quality of the included studies. Random-effects meta-analyses were performed to pool estimates of proportions (with 95% confidence intervals [CIs]) of undiagnosed (1) subclinical, (2) overt, and (3) total hypothyroidism.
Results:
The search returned 15,565 citations (4,526 duplicates). Twenty papers were included in the study. Fourteen and 6 studies were of good and moderate methodological quality, respectively. The results of the meta-analyses were as follows for the prevalence of undiagnosed hypothyroidism: subclinical, 4.11% (95% CI 3.05-5.31%, I2 = 99.32%); overt, 0.65% (95% CI 0.38-0.99%, I2 = 96.67%); and total, 4.70% (95% CI 2.98-6.79%, I2 = 99.53%). According to the sensitivity analysis, the prevalence of hypothyroidism tends to be higher in female patients, in those aged ≥65 years, among studies with lower sample sizes, in those with thyroid-stimulating hormone levels <4.5 mIU/L, and in Eastern and Southern Europe.
Conclusions:
The current evidence suggests that a considerable proportion of the European population has hypothyroidism, particularly subclinical hypothyroidism, which is undiagnosed. This issue deserves further investigation because of possible deleterious consequences for public health.
Objective To systematically review, summarise, and appraise findings of published meta-analyses that examined the effects of caffeine on exercise performance.
Design Umbrella review.
Data sources Twelve databases.
Eligibility criteria for selecting studies Meta-analyses that examined the effects of caffeine ingestion on exercise performance.
Results Eleven reviews (with a total of 21 meta-analyses) were included, all being of moderate or high methodological quality (assessed using the AMSTAR 2 checklist). In the meta-analyses, caffeine was ergogenic for aerobic endurance, muscle strength, muscle endurance, power, jumping performance, and exercise speed. However, not all analyses provided a definite direction for the effect of caffeine when considering the 95% prediction interval. Using the GRADE criteria the quality of evidence was generally categorised as moderate (with some low to very low quality of evidence). Most individual studies included in the published meta-analyses were conducted among young men.
Summary/Conclusion Synthesis of the currently available meta-analyses suggest that caffeine ingestion improves exercise performance in a broad range of exercise tasks. Ergogenic effects of caffeine on muscle endurance, muscle strength, anaerobic power, and aerobic endurance were substantiated by moderate quality of evidence coming from moderate-to-high quality systematic reviews. For other outcomes, we found moderate quality reviews that presented evidence of very low or low quality. It seems that the magnitude of the effect of caffeine is generally greater for aerobic as compared with anaerobic exercise. More primary studies should be conducted among women, middle-aged and older adults to improve the generalisability of these findings.
Background:
General anaesthesia combined with epidural analgesia may have a beneficial effect on clinical outcomes. However, use of epidural analgesia for cardiac surgery is controversial due to a theoretical increased risk of epidural haematoma associated with systemic heparinization. This review was published in 2013, and it was updated in 2019.
Objectives:
To determine the impact of perioperative epidural analgesia in adults undergoing cardiac surgery, with or without cardiopulmonary bypass, on perioperative mortality and cardiac, pulmonary, or neurological morbidity.
Search methods:
We searched CENTRAL, MEDLINE, and Embase in November 2018, and two trial registers up to February 2019, together with references and relevant conference abstracts.
Selection criteria:
We included all randomized controlled trials (RCTs) including adults undergoing any type of cardiac surgery under general anaesthesia and comparing epidural analgesia versus another modality of postoperative pain treatment. The primary outcome was mortality.
Data collection and analysis:
We used standard methodological procedures as expected by Cochrane.
Main results:
We included 69 trials with 4860 participants: 2404 given epidural analgesia and 2456 receiving comparators (systemic analgesia, peripheral nerve block, intrapleural analgesia, or wound infiltration). The mean (or median) age of participants varied between 43.5 years and 74.6 years. Surgeries performed were coronary artery bypass grafting or valvular procedures and surgeries for congenital heart disease. We judged that no trials were at low risk of bias for all domains, and that all trials were at unclear/high risk of bias for blinding of participants and personnel taking care of study participants.Epidural analgesia versus systemic analgesiaTrials show there may be no difference in mortality at 0 to 30 days (risk difference (RD) 0.00, 95% confidence interval (CI) -0.01 to 0.01; 38 trials with 3418 participants; low-quality evidence), and there may be a reduction in myocardial infarction at 0 to 30 days (RD -0.01, 95% CI -0.02 to 0.00; 26 trials with 2713 participants; low-quality evidence). Epidural analgesia may reduce the risk of 0 to 30 days respiratory depression (RD -0.03, 95% CI -0.05 to -0.01; 21 trials with 1736 participants; low-quality evidence). There is probably little or no difference in risk of pneumonia at 0 to 30 days (RD -0.03, 95% CI -0.07 to 0.01; 10 trials with 1107 participants; moderate-quality evidence), and epidural analgesia probably reduces the risk of atrial fibrillation or atrial flutter at 0 to 2 weeks (RD -0.06, 95% CI -0.10 to -0.01; 18 trials with 2431 participants; moderate-quality evidence). There may be no difference in cerebrovascular accidents at 0 to 30 days (RD -0.00, 95% CI -0.01 to 0.01; 18 trials with 2232 participants; very low-quality evidence), and none of the included trials reported any epidural haematoma events at 0 to 30 days (53 trials with 3982 participants; low-quality evidence). Epidural analgesia probably reduces the duration of tracheal intubation by the equivalent of 2.4 hours (standardized mean difference (SMD) -0.78, 95% CI -1.01 to -0.55; 40 trials with 3353 participants; moderate-quality evidence). Epidural analgesia reduces pain at rest and on movement up to 72 hours after surgery. At six to eight hours, researchers noted a reduction in pain, equivalent to a reduction of 1 point on a 0 to 10 pain scale (SMD -1.35, 95% CI -1.98 to -0.72; 10 trials with 502 participants; moderate-quality evidence). Epidural analgesia may increase risk of hypotension (RD 0.21, 95% CI 0.09 to 0.33; 17 trials with 870 participants; low-quality evidence) but may make little or no difference in the need for infusion of inotropics or vasopressors (RD 0.00, 95% CI -0.06 to 0.07; 23 trials with 1821 participants; low-quality evidence).Epidural analgesia versus other comparatorsFewer studies compared epidural analgesia versus peripheral nerve blocks (four studies), intrapleural analgesia (one study), and wound infiltration (one study). Investigators provided no data for pulmonary complications, atrial fibrillation or flutter, or for any of the comparisons. When reported, other outcomes for these comparisons (mortality, myocardial infarction, neurological complications, duration of tracheal intubation, pain, and haemodynamic support) were uncertain due to the small numbers of trials and participants.
Authors' conclusions:
Compared with systemic analgesia, epidural analgesia may reduce the risk of myocardial infarction, respiratory depression, and atrial fibrillation/atrial flutter, as well as the duration of tracheal intubation and pain, in adults undergoing cardiac surgery. There may be little or no difference in mortality, pneumonia, and epidural haematoma, and effects on cerebrovascular accident are uncertain. Evidence is insufficient to show the effects of epidural analgesia compared with peripheral nerve blocks, intrapleural analgesia, or wound infiltration.
Background:
Spine surgery may be associated with severe acute postoperative pain. Compared with systemic analgesia alone, epidural analgesia may offer better pain control. However, epidural analgesia has sometimes been associated with rare but serious complications. Therefore, it is critical to quantify the real benefits of epidural analgesia over other modes of pain treatment.
Objectives:
To assess the effectiveness and safety of epidural analgesia compared with systemic analgesia for acute postoperative pain control after thoraco-lumbar spine surgery in children.
Search methods:
We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase and Cumulative Index to Nursing and Allied Health Literature on 14 November 2018, together with the references lists of related reviews and retained trials, and two trials registers.
Selection criteria:
We included all randomized controlled trials performed in children undergoing any type of thoraco-lumbar spine surgery comparing epidural analgesia with systemic analgesia for postoperative pain. We applied no language or publication status restriction.
Data collection and analysis:
We assessed risk of bias of included trials using the Cochrane tool. We analysed data using random-effects models. We rated the quality of the evidence according to the GRADE scale.
Main results:
We included 11 trials (559 participants) in the review, and seven trials (249 participants) in the analysis: 140 participants received epidural analgesia and 109 received systemic analgesia.Most studies included adolescents. Three trials included in the analysis contained some participants older than 18 years. The types of surgery were posterior spinal fusion for idiopathic scoliosis (nine trials), anterior correction for idiopathic scoliosis (one trial), or selective dorsal rhizotomy in children with cerebral palsy (one trial). The mean numbers of vertebrae operated on were between nine and 14.5 and the mean numbers of spinal levels were between three and four and a half. The length of surgery varied between three and six and a half hours.Compared with systemic analgesia, epidural analgesia reduced pain at rest at all time points. At six to eight hours, the mean pain score on a 0 to 10 scale with systemic analgesia was 3.1 (standard deviation 0.7) and with epidural analgesia was -1.32 points (95% confidence interval (CI) -1.83 to -0.82; 4 studies, 116 participants; moderate-quality evidence). At 72 hours, the mean pain score with epidural analgesia was equivalent to a -0.8 point reduction on a 0 to 10 scale (standardized mean difference (SMD) -0.65, 95% CI -1.19 to -0.10; 5 studies, 157 participants; moderate-quality evidence).Return of gastrointestinal functionThere was no difference for nausea and vomiting between groups (risk ratio (RR) 0.87, 95% CI 0.58 to 1.30; 6 studies, 215 participants; low-quality evidence). One study found epidural analgesia with local anaesthetics may have increased the number of participants who had their first flatus within 48 hours (RR 1.63, 95% CI 1.08 to 2.47; 30 participants; very low-quality evidence). Two studies found epidural analgesia with local anaesthetics may have increased the number of participants in whom first bowel movement occurred within 48 hours (RR 11.52, 95% CI 2.36 to 56.26; 60 participants; low-quality evidence). It was uncertain whether epidural analgesia reduced the time to first bowel movement (MD 0.09 days, 95% CI -0.32 to 0.50; 1 study, 60 participants; very low-quality evidence) and time to first liquid ingestion following epidural infusion of an opioid alone or a local anaesthetic plus an opioid (mean difference (MD) -5.02 hours, 95% CI -13.15 to 3.10; 2 studies, 56 participants; very low-quality evidence). Epidural analgesia with local anaesthetics may have increased the risk of having first solid food ingestion within 48 hours (RR 7.00, 95% CI 1.91 to 25.62; 1 study, 30 participants; very low-quality evidence).Secondary outcomesIt was uncertain whether there was a difference in time to ambulate (MD 0.08 days, 95% CI -0.24 to 0.39; 1 study, 60 participants; very low-quality evidence) and hospital length of stay (MD -0.29 days, 95% CI -0.69 to 0.10; 2 studies, 89 participants; very low-quality evidence). Two studies found participants were more satisfied when treated with epidural analgesia (MD 1.62 on a scale from 0 to 10, 95% CI 1.26 to 1.97; 60 participants; very low-quality evidence). It was unclear whether there was a difference in parent satisfaction for epidural analgesia with an opioid alone (MD 0.60, 95% CI -0.81 to 2.01; 1 trial, 27 participants; very low-quality evidence).ComplicationsIt was uncertain whether there was a difference in the risk of complications such as: respiratory depression (risk difference (RD) -0.05, 95% CI -0.16 to 0.05; 4 studies, 126 participants; very low-quality evidence); wound infection (RD 0.01, 95% CI -0.05 to 0.08; 2 trials, 93 participants; very low-quality evidence); epidural abscess (RD 0, 95% CI -0.05 to 0.05; 3 trials, 120 participants; very low-quality evidence); and neurological complications (RD 0.01, 95% CI -0.04 to 0.06; 4 studies, 151 participants; very low-quality evidence).
Authors' conclusions:
There is moderate- and low-quality evidence that there may be a small additional reduction in pain up to 72 hours after surgery with epidural analgesia compared with systemic analgesia. Two very small studies showed epidural analgesia with local anaesthetic alone may accelerate the return of gastrointestinal function. The safety of this technique in children undergoing thoraco-lumbar surgery is uncertain due to the very low-quality of the evidence. The study in 'Studies awaiting classification' may alter the conclusions of the review once assessed.
Aim: The purpose of this study was to compare the efficacy of Exposure and Response Prevention Therapy (ERP), Cognitive-Behavior Therapy (CBT) and third-wave behavior therapies on Obsessive-Compulsive Disorder (OCD) in Iranian population. Method: The research method was a meta-analysis and the statistical population of all researches conducted in Iran between 2005 and 2017 was 58 studies that among them, 34 studies were selected according to the inclusion and exclusion criteria as the research sample and finally reported 13 effect sizes for ERP, 19 effect sizes for CBT and 12 effect sizes for third-wave behavior therapies. The effect size index was the standardized mean difference also statistical analysis was done by comprehensive meta-analysis software. Results: The results showed that ERP (d= 1.815, P= 0.05), CBT (d= 1.542, P= 0.05) and third-wave behavior therapies (d= 1.688, P= 0.05) had been effective for OCD. Also study of type of treatment as a moderating variable didn't show significant difference. Conclusions: Based on the findings of this meta-analysis, it can be concluded that exposure is the most important therapeutic process in the treatment of OCD which it is an essential component in all three therapeutic approaches, and probably adding cognitive, mindfulness and acceptance components will not significantly contribute to the efficacy of behavioral therapy based on ERP in Iranian patients with OCD.
For any given research area, one cannot tell how many studies have been conducted but never reported. The extreme view of the "file drawer problem" is that journals are filled with the 5% of the studies that show Type I errors, while the file drawers are filled with the 95% of the studies that show nonsignificant results. Quantitative procedures for computing the tolerance for filed and future null results are reported and illustrated, and the implications are discussed. (15 ref) (PsycINFO Database Record (c) 2012 APA, all rights reserved)
Objective:
To assess the effect of publication bias on the results and conclusions of systematic reviews and meta-analyses.
Design:
Analysis of published meta-analyses by trim and fill method.
Studies:
48 reviews in Cochrane Database of Systematic Reviews that considered a binary endpoint and contained 10 or more individual studies.
Main outcome measures:
Number of reviews with missing studies and effect on conclusions of meta-analyses.
Results:
The trim and fill fixed effects analysis method estimated that 26 (54%) of reviews had missing studies and in 10 the number missing was significant. The corresponding figures with a random effects model were 23 (48%) and eight. In four cases, statistical inferences regarding the effect of the intervention were changed after the overall estimate for publication bias was adjusted for.
Conclusions:
Publication or related biases were common within the sample of meta-analyses assessed. In most cases these biases did not affect the conclusions. Nevertheless, researchers should check routinely whether conclusions of systematic reviews are robust to possible non-random selection mechanisms.
--To investigate factors associated with the publication of research findings, in particular, the association between "significant" results and publication.
--Follow-up study.
--Studies approved in 1980 or prior to 1980 by the two institutional review boards that serve The Johns Hopkins Health Institutions--one that serves the School of Medicine and Hospital and the other that serves the School of Hygiene and Public Health.
--A total of 737 studies were followed up.
--Of the studies for which analyses had been reported as having been performed at the time of interview, 81% from the School of Medicine and Hospital and 66% from the School of Hygiene and Public Health had been published. Publication was not associated with sample size, presence of a comparison group, or type of study (eg, observational study vs clinical trial). External funding and multiple data collection sites were positively associated with publication. There was evidence of publication bias in that for both institutional review boards there was an association between results reported to be significant and publication (adjusted odds ratio, 2.54; 95% confidence interval, 1.63 to 3.94). Contrary to popular opinion, publication bias originates primarily with investigators, not journal editors: only six of the 124 studies not published were reported to have been rejected for publication.
--There is a statistically significant association between significant results and publication.
Evidence based medicine insists on rigorous standards to appraise clinical interventions. Failure to apply the same rules to its own tools could be equally damaging
The advent of evidence based medicine has generated considerable interest in developing and applying methods that can improve the appraisal and synthesis of data from diverse studies. Some methods have become an integral part of systematic reviews and meta-analyses, with reviewers, editors, instructional handbooks, and guidelines encouraging their routine inclusion. However, the evidence for using these methods is sometimes lacking, as the reliance on funnel plots shows.
The funnel plot is a scatter plot of the component studies in a meta-analysis, with the treatment effect on the horizontal axis and some measure of weight, such as the inverse variance, the standard error, or the sample size, on the vertical axis. Light and Pillemer proposed in 1984: “If all studies come from a single underlying population, this graph should look like a funnel, with the effect sizes homing in on the true underlying value as n increases. [If there is publication bias] there should be a bite out of the funnel.”1 Many meta-analyses show funnel plots or perform various tests that examine whether there is asymmetry in the funnel plot and directly interpret the results as showing evidence for or against the presence of publication bias.
The plot's wide popularity followed an article published in the BMJ in 1997.2 That pivotal article has already received over 800 citations (as of December 2005) in the Web of Science. With two exceptions, this is more citations than for any other paper published by the BMJ in the past decade. The authors were careful to state many reasons why funnel plot asymmetry may not necessarily reflect publication bias. However, apparently many readers did not go beyond the …
Publication bias is the tendency to decide to publish a study based on the results of the study, rather than on the basis of its theoretical or methodological quality. It can arise from selective publication of favorable results, or of statistically significant results. This threatens the validity of conclusions drawn from reviews of published scientific research. Meta-analysis is now used in numerous scientific disciplines, summarizing quantitative evidence from multiple studies. If the literature being synthesised has been affected by publication bias, this in turn biases the meta-analytic results, potentially producing overstated conclusions. Publication Bias in Meta-Analysis examines the different types of publication bias, and presents the methods for estimating and reducing publication bias, or eliminating it altogether. Written by leading experts, adopting a practical and multidisciplinary approach. Provides comprehensive coverage of the topic including: • Different types of publication bias, • Mechanisms that may induce them, • Empirical evidence for their existence, • Statistical methods to address them, • Ways in which they can be avoided. • Features worked examples and common data sets throughout. • Explains and compares all available software used for analysing and reducing publication bias. • Accompanied by a website featuring software, data sets and further material. Publication Bias in Meta-Analysis adopts an inter-disciplinary approach and will make an excellent reference volume for any researchers and graduate students who conduct systematic reviews or meta-analyses. University and medical libraries, as well as pharmaceutical companies and government regulatory agencies, will also find this invaluable.
Quantitative research synthesis usually involves the combination of estimates of the standardized mean difference (effect size) derived from independent research studies. In some cases, effect size estimates are available only if the difference between experimental and control group means is statistically significant. If the quantitative result of a study is observed only when the mean difference is statistically significant, the observed mean difference, variance, and effect size are biased estimators of the corresponding population parameters. The exact distribution of the sample effect size is derived for the case in which only studies yielding statistically significant results may be observed. The maximum likelihood estimator of effect size also is derived under the model in which only significant results are observed. The exact distribution of the maximum likelihood estimator is obtained numerically and is used to study the bias of the maximum likelihood estimator. An empirical sampling study is used to supplement the analytic results.
Publication bias can be considered to have three stages: (1) Prepublication bias occurs in the performance of research, caused by ignorance, sloth, greed, or the double standard applied to clinical trials but not to clinical practice. (2) Publication bias refers to basing acceptance or rejection of a manuscript on whether it supports the treatment tested. Potentially biased reviewers are of equal concern. (3) Postpublication bias occurs in publishing interpretations, reviews, and meta-analyses of published clinical trials. Bias can be minimized by (1) insisting on high-quality research and thorough literature reviews, (2) eliminating the double standard concerning peer review and informed consent applied to clinical research and practice, (3) publishing legitimate trials regardless of their results, (4) requiring peer reviewers to acknowledge conflicts of interest, (5) replacing ordinary review articles with meta-analyses, and (6) requiring the authors of reviews to acknowledge possible conflicts of interest.
A study was performed to evaluate the extent to which the medical literature may be misleading as a result of selective publication of randomized clinical trials (RCTs) with results showing a statistically significant treatment effect. Three hundred eighteen authors of published trials were asked whether they had participated in any unpublished RCTs. The 156 respondents reported 271 unpublished and 1041 published trials. Of the 178 completed unpublished RCTs with a trend specified, 26 (14%) favored the new therapy compared to 423 of 767 (55%) published reports (p less than 0.001). For trials that were completed but not published, the major reasons for nonpublication were "negative" results and lack of interest. From the data provided, it appears that nonpublication was primarily a result of failure to write up and submit the trial results rather than rejection of submitted manuscripts. The results of this study imply the existence of a publication bias of importance both to meta-analysis and the interpretation of statistically significant positive trials.
Asymmetry in funnel plots may indicate publication bias in meta-analysis, but the shape of the plot in the absence of bias depends on the choice of axes. We evaluated standard error, precision (inverse of standard error), variance, inverse of variance, sample size and log sample size (vertical axis) and log odds ratio, log risk ratio and risk difference (horizontal axis). Standard error is likely to be the best choice for the vertical axis: the expected shape in the absence of bias corresponds to a symmetrical funnel, straight lines to indicate 95% confidence intervals can be included and the plot emphasises smaller studies which are more prone to bias. Precision or inverse of variance is useful when comparing meta-analyses of small trials with subsequent large trials. The use of sample size or log sample size is problematic because the expected shape of the plot in the absence of bias is unpredictable. We found similar evidence for asymmetry and between trial variation in a sample of 78 published meta-analyses whether odds ratios or risk ratios were used on the horizontal axis. Different conclusions were reached for risk differences and this was related to increased between-trial variation. We conclude that funnel plots of meta-analyses should generally use standard error as the measure of study size and ratio measures of treatment effect.
Estimating the normal mean and variance under a selection model
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Publication bias in clinical trials
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Funnel plots for detecting bias in meta-analysis: guidelines on choice of axis
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