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Introduction to meta-analysis

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... In meta-analysis, the population size increases through the synthesis of individual research results, and the statistical power of the overall analysis results increases, enabling more accurate parameter testing (Borenstein et al., 2009). Meta-analysis overcomes the limitations of individual studies' low statistical power by reducing the standard error of the weighted average effect size (ES; Cohn & Becker, 2003). ...
... It is necessary to conduct analysis by removing specific outliers and recalculating the weighted average ESs because extreme ESs such as outliers can skew the weighted average ES (Borenstein et al., 2009). The extreme ES was first checked by examining the residuals of each ES to determine if there were outliers. ...
... For an SCD study, the ES was calculated for each individual study because the ES cannot be calculated for each individual participant. The categorical variables were analyzed through meta-ANOVA(Borenstein et al., 2009). ...
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This study synthesized 14 published and unpublished group design and single-case design studies on bullying interventions for individuals with disabilities. The specific objectives were to examine the general characteristics and design qualities of the studies, quantify the magnitude of the intervention effects, and identify potential moderating variables. Four studies were excluded from the meta-analysis due to being outliers or having insufficient data. The design qualities of the 14 studies were assessed before conducting the meta-analysis. Analysis of the study characteristics revealed that approximately one-third of the studies included participants with a singular diagnosis, many of the participants were elementary or secondary high school age, researcher was the most common implementer, schools were the most common setting, and interventions targeted bully victims more than bullies themselves. The results indicated that six studies (43%) met the What Works Clearinghouse Design Standards, with or without reservations. The overall effect size for bullying intervention with individuals with disabilities was small, and effect size of individual studies was small to large. Interventions implemented by teachers had the largest effect size; however, no statistical significance was found across implementers. Implications for practice and future research are discussed in the following areas: implementer, dose of intervention, and implementation supports.
... Five studies in the meta-analysis used multiple measures representing the same construct. Therefore, the weighted averaging procedure was conducted by employing a calculator created by Lenhard and Lenhard (2014) to address the dependence issue (Borenstein et al., 2009). For example, Arbaugh (2013) reported the correlation coefficients between facilitating discourse and perceived learning, and between direct instruction and perceived learning to represent the correlation between teaching presence and perceived learning. ...
... The CMA software during analysis converts Pearson's r to Fisher's z to calculate averaged Fisher's z scores and then converts back to correlation r (Borenstein et al., 2009). The current study does not use Pearson's correlation r because variance heavily depends on the correlation (Borenstein et al., 2009). ...
... The CMA software during analysis converts Pearson's r to Fisher's z to calculate averaged Fisher's z scores and then converts back to correlation r (Borenstein et al., 2009). The current study does not use Pearson's correlation r because variance heavily depends on the correlation (Borenstein et al., 2009). In addition, Fisher's z transformation was used to normalize the sampling distribution of Pearson's r. ...
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The Community of Inquiry (CoI) framework describes three essential presences (i.e., teaching presence, cognitive presence, and social presence) and how these presences interact in providing an educational experience in online and blended learning environments. This meta-analysis examined 19 empirical studies on the CoI Presences (teaching presence, social presence, and cognitive presence) and their correlations with learning outcomes, including actual learning, perceived learning, and satisfaction. It was found that teaching presence and actual learning were moderately positively correlated, (r = .353). There was a weak correlation between cognitive presence and actual learning, (r = .250) and social presence and actual learning, (r = .199). For the correlation between the presences and perceived learning, cognitive presence and perceived learning was found to be strongly correlated, (r = .663), followed by the moderate correlation between social presence and perceived learning (r = .432), and teaching presence and perceived learning, (r = .392). With respect to satisfaction, the correlation between cognitive presence and satisfaction (r = .586), and between teaching presence and satisfaction was strong (r = .510), but the correlation between social presence and satisfaction was moderate (r = .447). The findings have implications for designers and instructors who design and teach online and blended courses to include these presences.
... For preventing the violation of the independence of observations, we inspected studies from the same authors, checking for possible duplicate samples (e.g., Zhao et al., 2015Zhao et al., , 2018. Studies with between-or within-participants design were included as well as studies with pre-/post-or with only post-training assessment, given that effect sizes do not depend on these methodological aspects (Borenstein et al., 2009). Note that for studies with multiple testing sessions along training (e.g., Cao et al., 2013a, b;Vinci-Booher et al., 2021), only the last testing in graph recognition, after the end of training, was considered. ...
... Next, Cohen's d was used to calculate Hedge's g (Hedges, 1982) to correct for possible bias due to small samples. Hedge's g is very close to Cohen's d when the number of participants in each study is ≥ 10 (Borenstein et al., 2009). We also checked that both computations led to equivalent statistical results. ...
... To examine the variation in ES between studies, the Q test of homogeneity was used (Q within ). The descriptive statistic, I 2 , was also used to determine the degree of heterogeneity, which quantifies the proportion of the observed variance among ES due to real differences among studies rather than sampling error (Borenstein et al., 2009). By convention, I 2 values of 25%, 50%, and 75% indicate low, moderate, and high values of heterogeneity, respectively (Higgins et al., 2019). ...
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Handwriting (HW) training seems to boost recognition of visual graphs and learning to read more than other learning experiences. However, efects across studies appear to be variable and the underlying cognitive mechanism has been elusive. We thus conducted a meta-analysis on 50 independent experiments (with 1525 participants) to determine the magnitude of this HW beneft in visual graph recognition, while enlightening the underlying cognitive mechanism, by investigating four types of moderators: training program (type of control training, presence/absence of phonological training, and HW tasks adopted); set size and training regime (duration and frequency of session and total amount of training); granularity of visual discrimination and perceptual learning tasks; and age of participants. The beneft from HW training was moderate-to-large and signifcant (Hedge’s g = 0.58, SE = .09) and was also modulated by the type of control training (larger relative to motor, g = 0.78, than to visual control, g = 0.37), phonological training (larger when it was absent, g = 0.79, than present, g = 0.47), and granularity of visual discrimination (larger for fne-grained, g = 0.93, than coarse-grained, g = 0.19). These results seem consistent with symbolic accounts that hold that the advantage from HW training in visual graph recognition is about perceptual learning rather than the motor act. Multiple meta-regressions also revealed that training regime moderated the HW beneft. We conclude that HW training is efective to improve visual graph recognition, and hence is still relevant for literacy instruction in the present digital era.
... The effect sizes in the form of summary statistics reported across studies were sourced (i.e., correlations and mean differences) and converted into a common effect size metricin this instance-standardized mean difference (d), which represents the size of the effect in each study relative to the variability observed in that study (Borenstein et al., 2009). Data extraction estimation of d was limited to summary statistics to obtain the most direct approximation of the effect size (Lipsey & Wilson, 2001). ...
... Given that numerous studies included multiple outcomes, the unit of analysis was set at the study level in CMA, and the within-cluster correlation was set at ρ = 1.0, thus providing the most conservative estimate of variance for each study. These modeled assumptions address the issue of statistical dependency (i.e., clustering) that can emerge when multiple effect sizes require extraction from a given study (Borenstein et al., 2009). ...
... This would reflect the fact that smaller studies (which appear toward the bottom) are more likely to be published if they have larger than average effects, which is necessary for them to meet the criterion for statistical significance. We used Duval and Tweedie's Trim and Fill method to determine the possible number of missing studies due to the presence of publication bias in the funnel plot and then adjusting the effect size estimate to correct for this possible bias (Borenstein et al., 2009). Finally, we conducted a cumulative analysis for publication bias. ...
Article
Attachment security priming has important theoretical and practical implications. We review security priming theory and research and the recent concerns raised regarding priming. We then report the results of a meta-analysis of 120 studies ( N = 18,949) across 97 published and unpublished articles (initial pool was 1,642 articles) investigating the affective, cognitive, and behavioral effects of security priming. A large overall positive effect size ( d = .51, p < .001) was found across all affective, cognitive, and behavioral domains. The largest effect was found for affect-related outcomes ( d =.62, p < .001), followed by behavioral ( d = .44, p < .001), and cognitive ( d = .45, p < .001). Trait attachment anxiety and avoidance moderated the effects of subliminal security priming for behavioral outcomes—security priming effects were larger among people higher on attachment anxiety and avoidance. Assessment of publication bias revealed mixed evidence for the possible presence of asymmetry.
... Despite its inclusion of unpublished studies, van Witteloostuijn et al.'s (2017) review still suffered from methodological limitations. For example, by neglecting the possible correlations of multiple effect sizes from a single study, their use of the random effects model potentially resulted in an inaccurate estimation of the overall effect size (Borenstein et al., 2021). ...
... After extracting the means and standard deviations (SD) of the statistical learning performance, indicated by accuracy or RT, for both groups in each study, we calculated the effect size by applying the R package esc (Lüdecke, 2017). In cases where statistical learning was indicated by the difference between two conditions (e.g., sequenced and random conditions for SRT tasks), we pooled the SDs of both conditions for each group if the SD of the between-condition difference was not reported (Borenstein et al., 2021). If an F-value or a t-value was reported instead of the means and SDs, we used the same R package to transform the For t-value into d. ...
... Since the Q value was not available in the RVE, we fitted the random effects model with aggregated effect sizes to examine the Q value. We also reported the RVE-based τ 2 and I 2 , which represent an absolute measure of between-studies variability (Schwarzer et al., 2017;von Hippel, 2015) and the ratio of true heterogeneity to total variance (Borenstein et al., 2021), respectively. ...
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A compelling demonstration of implicit learning is the human ability to unconsciously detect and internalize statistical patterns of complex environmental input. This ability, called statistical learning, has been investigated in people with dyslexia using various tasks in different orthographies. However, conclusions regarding impaired or intact statistical learning in dyslexia remain mixed. This study conducted a systematic literature search of published and unpublished studies that compared statistical learning between people with and without dyslexia using different learning paradigms in different orthographies. We identified 49 papers consisting of 59 empirical studies, representing the data from 1,259 participants with dyslexia and 1,459 typically developing controls. The results showed that, on average, individuals with dyslexia performed worse in statistical learning than age-matched controls, regardless of the learning paradigm or orthography (average weighted effect size d = 0.47, 95% confidence interval [0.36, 0.59], p < .001). Meta-regression analyses further revealed that the heterogeneity of effect sizes between studies was significantly explained by one reader characteristic (i.e., verbal IQ) but no task characteristics (i.e., task paradigm, task modality, and stimulus type). These findings suggest domain-general statistical learning weakness in dyslexia across languages, and support the need for a new theoretical model of statistical learning and reading, that is, the SLR model, which elucidates how reader and task characteristics are regulated by a multicomponent memory system when establishing statistically optimal representations for deep learning and reading.
... The implications of these limitations will be further discussed in Section 5.2. The benefit of meta-analysis is that it can include all the reported effects of previous studies in a single statistical synthesis combining the results of earlier works into a coherent summary figure (Borenstein et al., 2009). This aggregation of information leads to higher statistical power and more robust results than is possible in any individual study (Cohn and Becker, 2003). ...
... When undertaking a meta-analysis, the researcher must decide between using fixed or random effects (Borenstein et al., 2009). In the fixed effects model, the studies in the meta-analysis are assumed to constitute the entire universe of studies and, thus, the model only uses within-study variability in the error term. ...
... The weights are therefore dependent on between-study variance T 2 (for details of computing T 2 , see Borenstein et al., 2010) common to all studies in the sample and on individual studies' within-study variance Vi, which is calculated here (n denotes the sample size) simply, as in the fixed effects model, as (Borenstein et al., 2009): ...
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Purpose: It is commonly stated that increased board diversity leads to the heightened financial performance of firms via the impact that it can have on innovation, but the latter association has, thus far, remained empirically controversial. The aim of this paper is to shed light on this unresolved debate and gap in the literature via studying different types of diversity. Methodology: A meta-analysis was conducted on the existing empirical evidence on the topic to show whether such an association exists and compare cognitive (expertise and experience) and demographic diversity (gender, nationality and racial/ethnic). Findings: The results show that there is indeed a positive and statistically significant association between board diversity and firm innovation. This association is driven more by cognitive diversity of the board members than by demographic diversity. Research limitations: Potential publication bias, heterogeneity in the quality of the existing studies and the diversity in operationalising innovation and board diversity remain as limitations to this meta-analysis. Practical implications: Instead of focusing on selecting board members based on demographic (surface-level) diversity, selections should be based on the interplay of the experience, expertise and background demographic characteristics of the potential candidates. Otherwise, the minority members might face a "token" status. Originality: The results of this paper suggest that there is a positive association between board diversity and firm innovation. Future research should examine why this link exists. Therefore, the paper concludes with a research agenda for the benefit of potential further studies.
... Statistical methods perform efficiently as samples are larger [17]. During data aggregation, the effect sizes of all the replications are calculated first based on descriptive statistics, like means, variances or sample sizes or results of the experiment statistical tests and are then combined using a meta-analysis model [19], [46]. ...
...  Following the conventions used in medicine to analyse groups of interrelated experiments, we fitted fixed-effects linear regression models with the main factor TREATMENT and EXPERIMENT to analyse the data [59], [60]. We chose linear regression over meta-analysis of effect sizes [46], as: (1) access to the raw data is guaranteed within the family, and (2) all the replications have identical response variable operationalizations. We fitted a fixed-effects linear regression instead of a randomeffects model (i.e., linear mixed model with EX-PERIMENT as a random factor and TREATMENT as a random effect) because: (1) experiment operationalizations are identical, and (2) populations are similar across the replications. ...
... If the control conditions differ markedly across the replications (and, thus, the estimate of the control condition in baseline experiment is uninformative for assessing the magnitude of the TREATMENT estimate), we assess the magnitude of the TREATMENT estimate considering the control estimates of the other experiments also.  To ease the integration of results in future metaanalyses [46], we provide Cohen's d effect sizes [64], alongside their interpretation (i.e., small, medium, large) and their corresponding variances for all the pairwise comparisons made (i.e., the adoption/non-adoption of each usability mechanism for each response variable) for all the experiments. We used the R package effsize [65] to compute the effect sizes and their respective variances. ...
Article
Context: The usability software quality characteristic aims to improve system user performance. In a previous study, we found evidence of the impact of a set of usability features from the viewpoint of users in terms of efficiency, effectiveness and satisfaction. However, the impact level appears to depend on the usability feature and suggest priorities with respect to their implementation depending on how they promote user performance. Objectives: We use a family of three experiments to increase the precision and generalization of the results in the baseline experiment and provide findings regarding the impact on user performance of the Abort Operation, Progress Feedback and Preferences usability mechanisms. Method: We conduct two replications of the baseline experiment in academic settings. We analyse the data of 366 experimental subjects and apply aggregation (meta-analysis) procedures. Results: We find that the Abort Operation and Preferences usability mechanisms appear to improve system usability a great deal with respect to efficiency, effectiveness and user satisfaction. Conclusions: We find that the family of experiments further corroborates the results of the baseline experiment. Most of the results are statistically significant, and, because of the large number of experimental subjects, the evidence that we gathered in the replications is sufficient to outweigh other experiments.
... Research and best practices on distance and online learning have been implemented in several distance courses (Seaman et al., 2018). Meta-analytic research reviews offer a critical synthesis of an entire body of research to help individuals understand the results of individual studies in the context of others (Borenstein et al., 2009). Meta-analyses are useful for establishing the presence and magnitude of an effect as well as quantifying effect-size variation in context. ...
... Similar to first-order meta-analyses which assume effect sizes are extracted from primary studies with independent samples of participants (Borenstein et al., 2009), second-order meta-analyses require the independence of samples of primary studies (Polanin et al., 2017). Dependency of effect sizes increases the risk of committing a Type I error (Borenstein et al., 2009). ...
... Similar to first-order meta-analyses which assume effect sizes are extracted from primary studies with independent samples of participants (Borenstein et al., 2009), second-order meta-analyses require the independence of samples of primary studies (Polanin et al., 2017). Dependency of effect sizes increases the risk of committing a Type I error (Borenstein et al., 2009). A Polanin et al.'s. ...
Article
Distance learning has evolved over many generations into its newest form of what we commonly label as online learning. In this second-order meta-analysis, we analyze 19 first-order meta-analyses to examine the impact of distance learning and the special case of online learning on students’ cognitive, affective and behavioral outcomes. We examine to what extent distance learning generation level, and instructional setting moderate the influences of distance learning on cognitive, affective and behavioral outcomes. This second-order meta-analyses also analyzes the first-order meta-analyses for methodological quality and robustness. The findings revealed a statistically significant overall average effect size (g = 0.156, p < .001 with a 95% confidence interval of 0.087–0.224) of distance learning impacting cognitive, affective and behavioral outcomes in comparison to face-to-face learning. Meta-analyses on higher education had a statistically significant larger effect size than K-12 education. Limitations, implications, and directions for future research are discussed.
... We conducted a meta-analysis using Comprehensive Meta-Analysis (CMA, version 3.3, Biostat, Englewood, NJ, USA) software. First, given the between-study heterogeneity, we combined the effect size estimates using random-effect models [66]. Based on previous studies [55,66], the overall effect size was calculated through an omnibus analysis. ...
... First, given the between-study heterogeneity, we combined the effect size estimates using random-effect models [66]. Based on previous studies [55,66], the overall effect size was calculated through an omnibus analysis. In this review, the effect sizes of most selected studies were extracted based on Pearson's correlation coefficients (r) for correlational data or calculated from other convertible statistics, such as log odds ratios for binary data and standardized mean difference for continuous data [66]. ...
... Based on previous studies [55,66], the overall effect size was calculated through an omnibus analysis. In this review, the effect sizes of most selected studies were extracted based on Pearson's correlation coefficients (r) for correlational data or calculated from other convertible statistics, such as log odds ratios for binary data and standardized mean difference for continuous data [66]. ...
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This study aimed to conduct a quantitative synthesis of the clinical correlates of caregiver burden in schizophrenia studies published in the last two decades. Derived from eight electronic databases, this meta-analytic review revisits 34 English articles published from 2000 to 2020 relevant to family caregiver burden in the schizophrenia field. The Newcastle–Ottawa Scale (NOS) was used to assess study quality. The pooled effect sizes of the selected studies ranged from −0.390 to 0.751. The results indicated a significant association between a heavier burden and disease-related risk factors, including more severe symptoms, greater general psychopathology, greater severity of functional impairment, and longer duration of illness. The results show moderating effects of study characteristics (i.e., study quality, participants, and location) on the correlations between these disease-related risk factors and caregiver burden. This review highlights the roles of study characteristics in affecting the inconsistent results for the effects of disease-related risk factors on caregiver burden in families of patients with schizophrenia. Psychosocial interventions are essential for family caregivers of persons with schizophrenia. Future studies incorporating random samples from both high-income and low-to-middle-income countries will be crucial to understand the effects of cultural contexts on caregiver burden in families of persons with schizophrenia.
... The study of heterogeneity can provide indications on how to interpret the overall effect size of each meta-analysis (Borenstein et al., 2009). We assessed heterogeneity between studies with the I 2 and τ 2 (Borenstein et al., 2009) In addition, both anonymous reviewers of the protocol stressed the importance of including relevant qualitative works to achieve the objectives of this review. ...
... The study of heterogeneity can provide indications on how to interpret the overall effect size of each meta-analysis (Borenstein et al., 2009). We assessed heterogeneity between studies with the I 2 and τ 2 (Borenstein et al., 2009) In addition, both anonymous reviewers of the protocol stressed the importance of including relevant qualitative works to achieve the objectives of this review. For these reasons, this systematic review includes quantitative studies as well as qualitative studies. ...
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Studies from multiple contexts conceptualize organized crime as comprising different types of criminal organizations and activities. Notwithstanding growing scientific interest and increasing number of policies aiming at preventing and punishing organized crime, little is known about the specific processes that lead to recruitment into organized crime. This systematic review aimed at (1) summarizing the empirical evidence from quantitative, mixed methods, and qualitative studies on the individual‐level risk factors associated with the recruitment into organized crime, (2) assessing the relative strength of the risk factors from quantitative studies across different factor categories and subcategories and types of organized crime. We searched published and unpublished literature across 12 databases with no constraints as to date or geographic scope. The last search was conducted between September and October 2019. Eligible studies had to be written in English, Spanish, Italian, French, and German. Studies were eligible for the review if they: Reported on organized criminal groups as defined in this review. Investigated recruitment into organized crime as one of its main objectives. Provided quantitative, qualitative, or mixed methods empirical analyses. Discussed sufficiently well‐defined factors leading to recruitment into organized crime. Addressed factors at individual level. For quantitative or mixed‐method studies, the study design allowed to capture variability between organized crime members and non‐members. Reported on organized criminal groups as defined in this review. Investigated recruitment into organized crime as one of its main objectives. Provided quantitative, qualitative, or mixed methods empirical analyses. Discussed sufficiently well‐defined factors leading to recruitment into organized crime. Addressed factors at individual level. For quantitative or mixed‐method studies, the study design allowed to capture variability between organized crime members and non‐members. From 51,564 initial records, 86 documents were retained. Reference searches and experts' contributions added 116 additional documents, totaling 202 studies submitted to full‐text screening. Fifty‐two quantitative, qualitative, or mixed methods studies met all eligibility criteria. We conducted a risk‐of‐bias assessment of the quantitative studies while we assessed the quality of mixed methods and qualitative studies through a 5‐item checklist adapted from the CASP Qualitative Checklist. We did not exclude studies due to quality issues. Nineteen quantitative studies allowed the extraction of 346 effect sizes, classified into predictors and correlates. The data synthesis relied on multiple random effects meta‐analyses with inverse variance weighting. The findings from mixed methods and qualitative studied were used to inform, contextualize, and expand the analysis of quantitative studies. The amount and the quality of available evidence were weak, and most studies had a high risk‐of‐bias. Most independent measures were correlates, with possible issues in establishing a causal relation with organized crime membership. We classified the results into categories and subcategories. Despite the small number of predictors, we found relatively strong evidence that being male, prior criminal activity, and prior violence are associated with higher odds of future organized crime recruitment. There was weak evidence, although supported by qualitative studies, prior narrative reviews, and findings from correlates, that prior sanctions, social relations with organized crime involved subjects, and a troubled family environment are associated with greater odds of recruitment. The available evidence is generally weak, and the main limitations were the number of predictors, the number of studies within each factor category, and the heterogeneity in the definition of organized crime group. The findings identify few risk factors that may be subject to possible preventive interventions.
... REML estimations were utilized as they do not underestimate the variance (Garcia-Argibay et al., 2019b; Thompson & Sharp, 1999). Further, we conducted a moderator analysis to evaluate whether the entrainment effect differs between attention and memory studies (Polanin, 2021). We installed the metafor, dplyr, robumeta, and clubSandwch packages. ...
... The findings of the moderator analysis assisted in providing information regarding the moderator's statistical significance. Meta-regression was also conducted to examine the relationship between the multiple variables in the selected studies and their effect sizes, using the REML estimator (Polanin, 2021). ...
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Binaural beats (BB) entrainment is an auditory perceptual occurrence that exists when two tones of separate frequencies are simultaneously presented to each ear. Research on BB entrainment has gained attention due to its ability to treat various conditions like anxiety, attention-deficit/hyperactivity (ADHD), etc. Even though research on BB entrainment suggests its efficiency in improving cognition among individuals, existing literature indicates mixed results in the cognitive domains of attention and memory. Thus, we conducted meta-analysis to examine the effect of BB intervention on memory and attention, respectively, in the current paper. We further performed a systematic review on the selected studies to report their variables, demographic characteristics of the participants, and outcomes to comprehensively position the research on BB intervention exclusively in the areas of memory and attention. Fifteen studies met our inclusion criteria. Based on 31 effect sizes, the results indicated an overall medium and significant effect size (g = 0.40). Findings from systematic review reveal conflicting results, especially concerning theta and beta's efficacy on memory (recall and recognition tasks) and attention-related tasks. The findings of the current paper add to the growing evidence that BB intervention improves attention and memory in humans. Since the findings suggest a near-moderate effect of BB interventions and mixed results in the systematic review, more research with robust study designs must explore its guiding principle and the expanding role of brainwaves in improving memory and attention in individuals. Such an intervention has important implications in both clinical and non-clinical settings.
... That is, even though the workers in the exposed groups (3-15 and >15 years) are not the same, both groups are compared against the same reference group of 40-50 dB(A) (see Table 3 of Hwang et al. (2012)). This is a classic problem of non-independence that methodologists have warned against (Borenstein et al. 2009;Cheung 2019). • Fourth, as indicated by Bolm-Audorff et al. (2022), for their metaanalysis, they computed some (unadjusted) effect estimates from raw data for some studies and pooled them together with adjusted estimates from other studies. ...
... This method has been employed in a previous Cochrane review (Pasquali et al., 2018) (for detailed calculation notes see Appendix 3 in the Supplementary data). We followed the principles outlined by Borenstein et al. (2009)". Additionally, in Supplementary Table A3.1 of Teixeira et al. (2021a) "Combining across multiple comparisons within a single study" we reported in detail how we calculated this risk estimate for Tessier-Sherman et al. (2017). ...
... In addition to the type of effect size used, the independence of effect sizes is a key assumption of meta-analysis (Cheung, 2019). However, studies in metaanalyses of education frequently combine dependent effect sizes, as when (a) participants complete a battery of measures or assessments at multiple points in time or (b) researchers compare multiple treatment groups with a single control group (Borenstein et al., 2011). Inappropriately assuming the independence of dependent effects results in studies with multiple measures receiving more weight in the analysis, which potentially distorts results (Cheung, 2019). ...
... The model employed in meta-analyses also influences the weight assigned to effects of an individual study. A fixed-effects meta-analysis assumes included studies estimate the same effect across similar populations under similar circumstances, and attributes error to within study sampling (Borenstein et al., 2011). Consequently, studies in a fixed-effects model are often weighted according to sample size. ...
Article
Learning disabilities (LD) may affect a range of academic skills but are most often observed in reading. Researchers and policymakers increasingly recommend addressing reading difficulties encountered by students with LD using evidence- based practices, or interventions validated through multiple, high-quality research studies. A valuable tool in identifying evidence-based practices is the meta-analysis, which entails statistically aggregating the results obtained through primary studies. Specific methods used in meta-analyses have the potential to influence their findings, with ramifications for research and practice. This review assessed the methodological features of the systematic reviews and analytic procedures featured in meta-analyses of reading intervention studies that included students with LD written between 2000 and 2020. Identified articles (n = 23) suggest that meta-analyses have become more prevalent and transparent over time, notwithstanding issues related to publication bias and the opacity of coding procedures. A discussion of implications follows a description of results.
... 7. The methodological description of the meta-analysis presented in this paper is kept to a minimum due to space limitations. For more details, see Borenstein et al. (2009), Stanley and Doucouliagos (2012), and Iwasaki (2020b, Chapter 1). 8. For East Germany, we used the distance from Brussels to Berlin. ...
... The I 2 and H 2 statistics measure the degree of heterogeneity across the studies using the Q statistic and the degree of freedom (DF) using the formula: I 2 = {(Q − DF)/Q} × 100% and H 2 = Q/DF, respectively. For more details, see Higgins and Thompson (2002) and Borenstein et al. (2009). 12. ...
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This paper conducts a meta-analysis of 1599 estimates extracted from 69 previous studies to identify time-series changes in returns to schooling in 20 European emerging markets. We examine possible difference in returns to schooling across the region. A meta-synthesis suggests a decreasing trend over time in returns to schooling in European emerging markets. Synthesis results also indicate that the western part of the region tends to have higher returns to schooling than the eastern part. Both the meta-regression analysis of literature heterogeneity and the test for publication selection bias produced findings that are highly consistent with the meta-synthesis results.
... Multiple meta-regression allows for the investigation of interactions and additive effects within a meta-regression model (Borenstein et al., 2011). This method allows the ability to combine and test all possible model predictor combinations and determines which predictors are the most important overall by comparing each model's corrected AIC value (Akaike Information Criterion; Akaike, 1974), creating an estimate for each predictor, and generating an estimate of predictor importance which ranges from 0-1 in value (Burnham & Anderson, 2002;Lindberg et al., 2015;Harrer et al., 2019). ...
... Dubbed the ‗file-drawer' problem, publication of small-sampled studies with large and significant effects, but not small-sampled studies with small or non-significant effects, can increase the pooled effect of a given intervention(Dickersin, 2005). Recently alternative methods for reporting informative statistics have been suggested(Dirnagl, 2019;Halsey, 2019), and it remains important to evaluate the possibility of ‗file-drawer' publication bias in studies using the iTBS protocol occurring due to nonpublication according to this significance standard.Small sample bias methods were utilized to assess publication bias, which are able to determine if small studies with small effect sizes are missing J o u r n a l P r e -p r o o f(Borenstein et al., 2011). The assumptions required to run these analyses include 1) large studies are likely to be published regardless of significance, 2) moderately sized studies with insignificant findings are at greater risk of not being published but are more represented in the literature as compared to small studies, and 3) small studies are at the greatest risk of not being published because of nonsignificant findings and thus should have the largest proportion of missing values. ...
Article
Intermittent theta-burst stimulation (iTBS) has been used to focally regulate excitability of neural cortex over the past decade – however there is little consensus on the generalizability of effects reported in individual studies. Many studies use small sample sizes (N < 30), and there is a considerable amount of methodological heterogeneity in application of the stimulation itself. This systematic meta-analysis aims to consolidate the extant literature and determine if up-regulatory theta-burst stimulation reliably enhances cognition through measurable behavior. Results show that iTBS – when compared to suitable control conditions — may enhance cognition when outlier studies are removed, but also that there is a significant amount of heterogeneity across studies. Significant contributors to between-study heterogeneity include location of stimulation and method of navigation to the stimulation site. Surprisingly, the type of cognitive domain investigated was not a significant contributor of heterogeneity. The findings of this meta-analysis demonstrate that standardization of iTBS is urgent and necessary to determine if neuroenhancement of particular cognitive faculties are reliable and robust, and measurable through observable behavior.
... If means and standard deviations were not reported, we used other statistics (F, t, or p-value) to calculate effect sizes. For dichotomous outcomes, Log Odds Ratios were calculated and converted to Hedges' g in order to pool across different effect size formats [21]. Hedges' g can be interpreted as Cohen's d, with an effect size of ≥ 0.20 representing a small, ≥ 0.50 a medium and ≥ 0.80 a large difference between two groups [22]. ...
... Although we included a large sample of studies in our review and the moderator analyses were based on larger samples than in the existing reviews, statistical power of the moderator analyses might still pose a problem [88]. For that reason, non-significant findings should not be interpreted as evidence for a non-existent effect [21,89]. In addition to low statistical power, findings of moderator analyses are only observational and do not imply causal relationships [90]. ...
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Background and purpose: Laughter-inducing interventions hold promise as affordable and easy to implement treatments for a range of ailments. The aim of this study was to build on meta-analytic evidence for the efficacy of such interventions in treating somatic or mental health patients. Methods Studies eligible for the meta-analysis were identified by a comprehensive literature search in MEDLINE, CENTRAL, Web of Science, and PsycINFO and by a manual search (date of last search 22/06/2021). All randomized controlled trials comparing spontaneous laughter or simulated laughter to treatment as usual, no treatment/waitlist, or attention control groups were included. There were no language or date restrictions. Separate random-effects meta-analyses were conducted for mental health, physiological, and physical health outcomes. Hedges’ g is reported as the standardized mean difference estimate. The study was registered on PROSPERO (#CRD42019139299). Results Forty-five studies comprising 2,547 randomized participants were included. Laughter-inducing interventions showed significant positive effects on mental health (31 studies, 1,543 patients, g = 0.74, 95% CI [0.48; 1.00], I² = 81%), physiological (14 studies, 761 patients, g = 0.61 [0.20; 1.03], I² = 86%), and physical health outcomes (21 studies, 1,105 patients, g = 0.59 [0.30; 0.88], I² = 80%). Only one study reported adverse events, which were mild in nature. Conclusion Laughter-inducing interventions can have beneficial effects on a variety of health-related outcomes including mental health, physical health, and physiological parameters. Future research should also focus on examining differential intervention effects and mechanisms of action.
... The subgroup difference was assessed by a Qtest for heterogeneity in the random effects model. 16 Begg's and Egger's tests were performed to evaluate potential publication bias if the number of included studies was not <10. 17,18 All analyses were performed using R software (version 3.6.1) ...
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Background Ustekinumab is effective in treating Crohn’s disease (CD) and ulcerative colitis (UC). However, the loss of response (LOR) to ustekinumab and the efficacy of dose escalation have not been systematically explored. Methods Databases were searched for eligible studies from inception through July 2021. Summary estimates were pooled, and subgroup analyses were performed to explore heterogeneity. Results We included 14 studies (CD: 13; UC: 1). In CD patients, the annual risk of LOR to ustekinumab and dose escalation among primary responders was 21% (95% confidence interval [CI] 12–31%, 1530 person‐years, n = 9) per person‐year and 25% (95% CI 12–32%, 657 person‐years, n = 5) per person‐year respectively. Clinical response was regained in 58% (95% CI 49–67%, 279 patients, n = 8) of secondary non‐responders after dose escalation (interval reduction or intravenous reinduction). In UC patients, no studies provided data on LOR, but only one study showed that 35% (100/284) of patients underwent dose escalation (or sham dose adjustment), leading to an annual risk of dose escalation of 18% per person‐year. After dose escalation, 58% (14/24) of the patients regained symptomatic remission. Conclusions Primary responders with CD experienced LOR to ustekinumab at a risk of 21% per person‐year and required dose escalation at a risk of 25% per person‐year. Fifty‐eight per cent of secondary non‐responders with CD may benefit from dose escalation. LOR has not been well characterized in patients with UC.
... p-values correspond to the heterogeneities between studies from a Chi-squared test of the null hypothesis that there is no heterogeneity. The potential impact of publication bias on the present meta-analysis was assessed by three different analyses: funnel plot [36,37]; Egger's regression test [38,39] and Duval and Tweedie's Trim and Fill approach [40,41]. This allowed us to obtain the best estimate of the unbiased pooled effect size, creating a funnel plot including both the observed studies (shown as blue circles) and the necessary imputed studies (shown as red circles) to obtain the absence of bias. ...
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Members of the family Arcobacteraceae are distributed widely in aquatic environments, and some of its species have been associated with human and animal illness. However, information about the diversity and distribution of Arcobacteraceae in different water bodies is still limited. In order to better characterize the health risk posed by members in the family Arcobacteraceae, a systematic review and meta-analysis-based method was used to investigate the prevalence of Arcobacteraceae species in aquatic environments based on available data published worldwide. The database search was performed using related keywords and considering studies up to February 2021. The pooled prevalence in aquatic environments was 69.2%, ranging from 0.6 to 99.9%. These bacteria have a wide geographical distribution, being found in diverse aquatic environments with the highest prevalence found in raw sewage and wastewater treatment plants (WWTP), followed by seawater, surface water, ground water, processing water from food processing plants and water for human consumption. Assessing the effectiveness of treatments in WWTP in eliminating this contamination, it was found that the wastewater treatment may not be efficient in the removal of Arcobacteraceae. Among the analyzed Arcobacteraceae species, Al. butzleri was the most frequently found species. These results highlight the high prevalence and distribution of Arcobacteraceae in different aquatic environments, suggesting a risk to human health. Further, it exposes the importance of identifying and managing the sources of contamination and taking preventive actions to reduce the burden of members of the Arcobacteraceae family.
... We conducted eight multilevel, mixed-effects meta-analytic models: three using our three 'focal' effect sizes that averaged across treatments to get the main effects of EE, stress, and the interactive effect of EE and stress (these three models were later used for the meta-regression analyses), and five 'pairwise' effect sizes used as comparisons between treatment combinations (Fig. 1C). For each meta-analytic model, we also estimated a multilevel version of heterogeneity (I 2 ) which quantifies unexplained variation after accounting for sampling variance (Borenstein et al., 2021;Higgins et al., 2003;Nakagawa and Santos, 2012). ...
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Environmental enrichment (“EE”) is expected to alleviate the negative effects of stress on cognitive performance. However, there are complexities associated with interpreting interactions that obscure determining the benefit EE may play in mitigating the negative effects of stress. To clarify these complexities, we conducted a systematic review with meta-analysis on the main and interactive effects of EE and stress on learning and memory in rodents. We show that EE and stress interact ‘synergistically’ where EE provides a greater relative benefit to stressed individuals compared to those reared in conventional housing. Importantly, EE can fully-compensate for the negative effects of stress where stressed individuals with EE performed equally to enriched individuals without a stress manipulation. Additionally, we show the importance of other mediating factors, including the order of treatment exposure, duration and type of stress, type of EE, and type of cognitive assays used. This study not only quantifies the interactions between EE and stress, but also provides a clear example for how to conduct and interpret meta-analysis of interactions.
... To control for the existing non-independence of data coming from the same study, the factors "study" and "site" were used as random factors in the analyses (Xu et al., 2020). Effect sizes and variances were calculated using random-effects models with restricted maximum-likelihood estimators (Viechtbauer, 2005), which allow for sampling error and cross-study variability in true effect sizes (Viechtbauer, 2005;Borenstein et al., 2012). Effects were significant if bootstrap confidence intervals (CIs) did not overlap with zero (Collins et al., 1985;van den Noortgate and Onghena, 2005). ...
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Fire is a very common disturbance in terrestrial ecosystems and can give rise to significant effects on soil carbon (C) cycling and storage. Here, we conducted a global meta-analysis on the response of soil C cycling and storage across soil profiles (organic layer, 0-5 cm, 0-10 cm, 0-20 cm, and 20-100 cm) to fire reported in 308 studies across 383 sites and examined the role of fire frequency, fire type, soil type, ecosystem type, and post-fire time in regulating the response of soil C dynamics to fire. Overall, we found soil C cycling and storage were more responsive to one fire and wildfire as compared to frequent fire and prescribed fire, respectively. Soil respiration significantly decreased by 22±9% by one fire, but was not significantly affected by frequent fire across ecosystems. One fire significantly reduced soil C content in the organic, 0-10 cm, and 20-100 cm layers by 27±16%, 10±9%, and 33±18%, respectively, while frequent fire significantly reduced soil C content at a depth of 0-5 cm and 0-20 cm by 29±8% and 16±12%, respectively. Soil C cycling and storage showed little response to frequent prescribed fire. In addition, the response of soil C cycling and storage varied among different soil and ecosystem types, with a stronger response being observed in forest than in grassland. Within 20 years post-fire, soil C cycling and storage tended to recover only after one fire but not after frequent fire. We also found that soil physicochemical properties and microbial communities were more responsive to one fire than frequent fire, which can indirectly affect the effects of fire on soil C cycling and storage. The results of our study filled some critical gaps in previous meta-analyses in fire ecology.
... In all cases, we computed the variance of the effect size from different populations, which were then used as weights in linear regressions. The inverse-variance weighting allows combining the results from independent measurements, giving more importance to the least noisy measurements and vice versa(Borenstein et al., 2009). ...
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Many species are shifting their ranges and being forced to rapidly respond to novel stressful environmental conditions. Colonizing individuals experience strong selective forces that favor the expression of life history traits notably affecting dispersal and reproductive rates in newly invaded habitats. Limited information is currently available on trait variation within the invasive range despite being critical for understanding ecological and evolutionary factors that drive the process of range expansion of invasive species. Here we evaluated life history shifts in the widely introduced Asian clam Corbicula cf. C. fluminea within its invaded range. Through an exhaustive literature search, we obtained data for 17 invasive populations of this clam from different ecosystems worldwide. We tested the relationship between population and individual parameters relevant to the process of range expansion. Our main results are that recently introduced populations of clams were characterized by (a) low density and low rate of population increase, (b) earlier reproduction in slow‐growing populations of clams, and (c) no effect of density on population increase. All populations of the Asian clam analyzed in this study, which are fixed for one genotype (the lineage called Form A/R), experienced different selective environments in the introduced range. These findings support the perspective that adaptive phenotypic plasticity favored the expression of traits that maximize fitness in recently established populations, which faced stronger r‐selective forces relative to long‐established ones. We discuss the role of plasticity in facilitating rapid adaptation and in increasing the likelihood of populations to overcome difficulties associated with low densities and low population increase in newly invaded areas.
... For publication bias analyses, we accounted for dependence using aggregates of all the effect sizes coming from the same sample 14 . We implemented the PET-PEESE method 15 , the trim-and-fill method 16 , and a selection model 17 to identify evidence of publication bias, and to adjust the final effect size. ...
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Background Many meta-analytic reviews have examined the cognitive benefits of regular physical exercise across the lifespan, with a wide range of inclusion criteria and disparate analytic approaches. In fact, most global health organizations incorporate the purported cognitive benefits as part of their policies to promote regular physical exercise. We assess whether those claims are well supported by scientific evidence. Methods We conducted a pre-registered (PROSPERO: CRD42020191357) umbrella review of meta-analyses limited to randomized controlled trials (RCTs) on exercise–cognition. Outcomes of each meta-analysis were reanalyzed following a multilevel model approach. Publication bias was also analyzed to correct final effect sizes. Findings Most of the 12 reviewed meta-analyses reported a positive small effect ( d = 0.21, [0.07–0.40]) of physical exercise across all cognitive domains in all life stages. However, a critical assessment of the primary studies included in these reviews and the meta-analytic approaches used indicates that the evidence might not be reliable and therefore no strong conclusions should be drawn based on the existing evidence. We found that the literature has undergone an unusually rapid growth upon underpowered RCTs and potentially biased meta-analytic reviews. Interpretation The exponential accumulation of low-quality evidence on the exercise–cognition topic has led to stagnation in the field, hindering the discernment of the potential impact of exercise on cognition. We urge worldwide organizations committed to public health to reconsider their recommendations on the promotion of regular physical exercise to boost cognitive functions in the healthy population until high-quality empirical evidence confirms these exercise-induced cognitive benefits. Funding Spanish Ministry of Science and Innovation (PID2019-105635GB-I00 and PID2020-118583GB-I00).
... Publication bias arises when researchers release only desirable findings (Borenstein et al., 2021). To fix this threat, the funnel plot method, a helpful test for the likely existence of bias in meta-analyses (Egger et al., 1997), was examined. ...
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Research has revealed the extent and mechanism of the relation between language (dominated by alphabetic systems) and students’ mathematics learning, but when it comes to Chinese language (an orthographic system), nature remains elusive. In this meta-analysis we aim to quantify the size of the relation between Chinese language and mathematics and determine the mechanism under which the correlation works. With a random effect model, a moderate relation (r=0.36, 95%CI [0.34, 0.38]) between Chinese language and mathematics was identified in 34 studies with 27 unique samples and 58,995 participants. Both dimensions of Chinese language and domains of mathematics were verified as significant moderators. Differences and commonalities of the relation between (Chinese) language and mathematics were discussed compared with existing meta- analyses. The findings suggested that consistent with alphabetic languages such as English, Chinese phonological processing, especially Rapid Automatic Naming (RAN) had the weakest correlation with mathematics, while oral comprehension and comprehensive language produced the strongest relations with mathematics; and Chinese language had the strongest correla- tion with comprehensive mathematics. Compared with alphabetic languages, Chinese language showed a stronger correlation with calculations; Chinese RAN showed a weaker correlation with mathematics, while Chinese orthographic-related skills produced a superior correlation with mathematics. Research implications were also suggested.
... The iterative Paule-Mandel method was used to estimate between-study variance [21]. Heterogeneity between studies was explored using Cochran's Q statistic, Higgin's and Thompson's percentage of variability I 2 statistic to estimate the percentage of total variation across Nutrients 2022, 14, 3066 4 of 16 studies arising from heterogeneity rather than chance [22]. Heterogeneity was rated low, moderate, or substantial when the value of I 2 was less than 25%, 50%, or greater than or equal to 75%, respectively. ...
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Aim: The aims of this systematic review and meta-analysis were to assess to what extent probiotics/synbiotics reduce infectious complications after colorectal surgery and whether probiotics or synbiotics should be considered as perioperative measures preventing or reducing infectious complications after CRS and should be included in enhanced recovery programmes (ERP). Secondary aims were to answer practical questions precisely on the best formulation and the type and timing of probiotics or synbiotics in CRS. Method: This systematic review and quantitative meta-analysis were conducted in accordance with PRISMA 2020 guidelines. Inclusion criteria were randomised trials comparing perioperative probiotics/synbiotics with a placebo or standard care in elective colorectal surgery. Exclusion criteria were non-randomised trials. Overall infectious complications and surgical site infections (SSIs including both deep abdominal infections and wound (skin or under the skin) infections) were the primary outcomes. Secondary outcomes were pulmonary and urinary infections, wound infections, and anastomotic leaks. The databases consulted were Medline, Cochrane Database of Systematic Reviews, Scopus, and Clinical Trials Register. Risk of bias was assessed according to the GRADE approach. The analysis calculated the random effects estimates risk ratio (RR) for each outcome. Results: 21 trials were included; 15 evaluated probiotics, and 6 evaluated synbiotics. There were significantly fewer infectious complications (risk ratio (RR) 0.59 [0.47-0.75], I2 = 15%) and fewer SSI (RR 0.70 [0.52-0.95], I2 = 0%) in the probiotic or synbiotic group. There were also significantly fewer pulmonary infections (RR 0.35 [0.20-0.63]) and urinary infections RR 0.41 [0.19-0.87]) as opposed to anastomotic leaks (RR 0.83 [0.47-1.48]) and wound infections (RR 0.74 [0.53-1.03]). Sensitivity analyses showed no significant difference between probiotics and synbiotics in reducing postoperative infections (RR 0.55 [0.42-0.73] versus RR 0.69 [0.42-1.13], p = 0.46). Conclusions: Based on the finding of this study, probiotics/synbiotics reduce infectious complications after colorectal surgery. The effect size was more pronounced for pulmonary and urinary infections. From a practical aspect, some of the questions related to formulations and duration of probiotics or synbiotics need to be answered before including them definitively in enhanced recovery after colorectal surgery programmes.
... Specifically, the correlation coefficients in separate publications were converted to Fisher's z values, to produce summary effects and confidence intervals. These parameters were then converted back to the original metric (Hedges, Higgins, & Rothstein, 2009). These analyses were carried out using MedCalc® (version 20.018, MedCalc Software Ltd, https://www. ...
Article
Understanding how human senses are linked to eating behaviour and adiposity has been a key topic in sensory science, and a source of substantial controversy. Despite strong correlations in sensitivity across different sensory modalities, the fundamental question of whether individuals possess a ‘generalised sensitivity’ across senses remains unanswered. A better understanding of the relationships between multiple senses and eating behaviour is needed to tackle the current obesity epidemic. The present study synthesises published data regarding sensory sensitivities across modalities and presents new empirical findings. Specifically, we synthesise findings from 115 publications, including meta-analyses of 26 studies. These data reveal strong yet complex links between senses, highlighting the potential of multi-sensory analyses to better characterise sensory variations. In the empirical study, 98 Caucasian males (25.9 ± 5.8 years of age; body mass index: 26.8 ± 5.1 kg∙m⁻²) are tested for their supra-threshold sensory sensitivities (d’) to 11 food-related mono-modal stimuli across olfaction, gustation, vision, and audition. Canonical correlations on d’ for each modality reveal significant positive correlations between olfaction and gustation (p < 0.001), vision and audition (p < 0.001), as well as olfaction and audition (p = 0.008). Additionally, K-means cluster analysis identifies three broad groups of individuals with distinct multi-sensory fingerprints. Intriguingly, individuals in separate clusters are shown to have significantly different adiposity measures (body mass index: p = 0.01; body fat percentages: p = 0.05). Overall, this study sheds important new light on multi-sensory ‘fingerprints’, and their links to obesity.
... The pooled estimate of correlation coefficients was calculated using Pearson's productmoment correlation with Fisher's transformation. Random-effects models were chosen because all the included studies focus on different chronic conditions and populations, meaning the sample distribution varies across studies and the parameters are drawn from random variables (Borenstein et al., 2011). The weight for each study (Wi) was calculated by the inverse of squared standard error (SEi 2 ) in correlation coefficient using the following equation: Wi = 1/SEi 2 . ...
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Background Living with chronic condition(s) is difficult, due in part to the complexities of effective disease self-care. Self-care has been considered a challenging process according to the literature which describes multiple barriers patients with chronic conditions experience. Resilience has the potential to buffer the adversities of daily self-care and maintain physical and emotional well-being. No systematic review and meta-analysis have been conducted to synthesise and quantify the relationship between resilience and self-care across chronic conditions. Aims (1) To examine how the definitions and measurements of self-care and resilience align with the middle-range theory of self-care of chronic illness (i.e. self-care maintenance, self-care monitoring, and self-care management) and 3 Rs of resilience process from the society-to-cells framework (i.e. resistance, recovery and rebound) across different chronic conditions; and (2) to examine whether and the degree to which resilience is correlated with self-care across different chronic conditions. Design Systematic review and meta-analysis, following PRISMA guidelines. Methods PubMed, CINAHL, SocINDEX and PsychINFO were searched for quantitative studies published from January 2000 through July 2020. Descriptive data were summarised using numerical counting to provide an overview of the study characteristics. Definitions and measurements of self-care and resilience were synthesised narratively based on self-care and resilience theories. Numerical data with Pearson's product–moment correlation among observational studies were examined using meta-analysis. Results This review included 20 articles, involving 9,269 individuals across 11 chronic conditions. Despite self-care and resilience being defined and operationalised in a variety of ways, most definitions shared some underlying core constructs. Meta-analysis showed a positive relationship between resilience and self-care across chronic conditions. Findings from interventional studies indicated a bidirectional relationship between resilience and self-care. Conclusions Overall, resilience was positively associated with self-care in people with chronic conditions. Longitudinal and experimental studies are needed to better understand the causal relationship between resilience and self-care.
... Since Pearson correlations were not normally distributed (Borenstein, Hedges, Higgins, & Rothstein, 2009), they were converted to Fisher's Zr for analysis and then back-transformed to r values for interpretation. In this meta-analysis, it was common that multiple effect sizes were obtained from a single sample; therefore, a three-level approach was used to model the dependency between different effect sizes from one sample (Cheung, 2014; Van den Noortgate, López-López, Marín-Martínez, & Sánchez-Meca, 2013; Van den Noortgate, López-López, Marín-Martínez, & Sánchez-Meca, 2015). ...
Article
Evaluative skill, the ability to accurately assess ideas in terms of originality or creativity, is a critical component of creativity. It involves discarding bad ideas and discerning ideas that are worthwhile to pursue. In light of the growing research on the association between individuals’ evaluative skill and divergent thinking (DT), a research synthesis is needed to clarify discrepant results. Therefore, we examined the relationship between DT and evaluative skill with a three‐level meta‐analytic approach. Based on 96 effect sizes in 20 studies with a total sample of 3,019 participants, results indicated that DT was positively associated with evaluative skill, r = .13 (95% CI [.07, .20], p < .001). Follow‐up moderator analyses revealed that the type of DT tests, the source of ideas, and the type of evaluation tasks were significant moderators. Compared with Instances, Line Meanings, and Consequences, the relationship was (a) weaker when the Uses task was used as the DT test, (b) stronger when the evaluation task was based on Uses, and (c) stronger when people rated their own ideas than when they rated others. The findings implied that DT and evaluative skill are conceptually distinct but interrelated and suggested ways to enhance evaluative skill.
... However, these findings might be due to low power since meta-regression analyses depend on the number and size of studies, magnitude of the relationship between the covariate and effect size, along with its precision and heterogeneity. 25 To the best of our knowledge, our study was the first to add IPD in an NMA of cognitive enhancers for patients with AD to produce treatment recommendations by patient characteristics. We followed the methods guidelines in the Cochrane Handbook for systematic reviews, 26 the reporting guidelines in the PRISMA-NMA and PRIS-MA-IPD statements 7 8 and evaluated credibility of findings using CINeMA. ...
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Objective: To examine the comparative efficacy and safety of cognitive enhancers by patient characteristics for managing Alzheimer's dementia (AD). Design: Systematic review and individual patient data (IPD) network meta-analysis (NMA) based on our previously published systematic review and aggregate data NMA. Data sources: MEDLINE, Embase, Cochrane Methodology Register, CINAHL, AgeLine and Cochrane Central Register of Controlled Trials up to March 2016. Participants: 80 randomised controlled trials (RCTs) including 21 138 adults with AD, and 12 RCTs with IPD including 6906 patients. Interventions: Cognitive enhancers (donepezil, rivastigmine, galantamine and memantine) alone or in any combination against other cognitive enhancers or placebo. Data extraction and synthesis: We requested IPD from authors, sponsors and data sharing platforms. When IPD were not available, we used aggregate data. We appraised study quality with the Cochrane risk-of-bias. We conducted a two-stage random-effects IPD-NMA, and assessed their findings using CINeMA (Confidence in Network Meta-Analysis). Primary and secondary outcomes: We included trials assessing cognition with the Mini-Mental State Examination (MMSE), and adverse events. Results: Our IPD-NMA compared nine treatments (including placebo). Donepezil (mean difference (MD)=1.41, 95% CI: 0.51 to 2.32) and donepezil +memantine (MD=2.57, 95% CI: 0.07 to 5.07) improved MMSE score (56 RCTs, 11 619 participants; CINeMA score: moderate) compared with placebo. According to P-score, oral rivastigmine (OR=1.26, 95% CI: 0.82 to 1.94, P-score=16%) and donepezil (OR=1.08, 95% CI: 0.87 to 1.35, P-score=30%) had the least favourable safety profile, but none of the estimated treatment effects were sufficiently precise when compared with placebo (45 RCTs, 15 649 patients; CINeMA score: moderate to high). For moderate-to-severe impairment, donepezil, memantine and their combination performed best, but for mild-to-moderate impairment donepezil and transdermal rivastigmine ranked best. Adjusting for MMSE baseline differences, oral rivastigmine and galantamine improved MMSE score, whereas when adjusting for comorbidities only oral rivastigmine was effective. Conclusions: The choice among the different cognitive enhancers may depend on patient's characteristics. The MDs of all cognitive enhancer regimens except for single-agent oral rivastigmine, galantamine and memantine, against placebo were clinically important for cognition (MD larger than 1.40 MMSE points), but results were quite imprecise. However, two-thirds of the published RCTs were associated with high risk of bias for incomplete outcome data, and IPD were only available for 15% of the included RCTs. Prospero registration number: CRD42015023507.
... This finding was supported by findings from different parts of the world suggesting that the provision of training positively influences the food handling practices of food handlers. [36][37][38] Likewise, the pooled estimate also indicated that food handlers having favourable attitudes were 3.62 times more likely to have good food handling practice compared with those who had unfavourable attitudes. Evidence also suggested that attitude was playing a significant role in promoting good food handling practice. ...
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Objectives Food handlers are individuals who are involved in food preparation, storage or service of food in a food facility. Unless they keep their personal hygiene, they are highly responsible for contaminating food or transmitting microbes to consumers. Thus, the main aim of this review was to pool the level of good food handling practice among food handlers working in public food establishments in Ethiopia. Design A systematic review and meta-analysis using the Joanna Briggs Institute (JBI) Critical Appraisal tool. Data sources PubMed, Google Scholar and Advanced Google were searched up to the end of February 2021. Eligibility criteria for selecting studies Publication status, publication language, type of study participants and the type of article were used to screen the article. Data extraction and study quality assessment All reviewers collected data independently and merged them together. A tool called the JBI Meta-Analysis of Statistics Assessment and Review Instrument was used to assess the quality of each research article. The assessment was performed by two reviewers. Result A total of 16 research articles were included in the review. The pooled level of good food handling practice was 50.72% with 95% CI (43.84% to 57.6%). Training (adjusted OR (AOR)=3.4, 95% CI (2.33 to 4.95)), attitude (AOR=3.62, 95% CI (2.23 to 5.85)) and medical check-up (AOR=5.12, 95% CI (2.93 to 8.95)) were identified as factors affecting good food handling practice with 95% CI at p<0.05. Conclusion The level of good food handling practice among food handlers working in public food establishments of Ethiopia was very low compared with literature, and variables such as food handler training, attitude towards good food handling practice and the existence of regular medical check-ups were factors affecting good food handling practice. Provision of training that could change the attitude and regular medical check-ups for food handlers has to be in place.
Article
The aim of this study was to evaluate the effect of control strategies (probiotic supplementation and vaccination) at farm on thermotolerant Campylobacter infection due to the consumption of salad cross‐contaminated from broiler meat. The broiler food chain was modelled considering the most common practices applied in Argentina (baseline model) and their effect on the prevalence and counts of Campylobacter. Probiotic supplementation and vaccination against Campylobacter spp. were included in different models to evaluate their effectiveness. The parameter distributions of each intervention were obtained based on a systematic review and meta‐analysis previously described. The control measures applied at farms were evaluated considering their effectiveness in reducing both the prevalence and the count of thermotolerant Campylobacter in comparison with the baseline model estimation and expressed as relative change in campylobacteriosis risk. Additionally, the identification of the most important input parameters for the model was performed by sensitivity analysis. The model estimated a risk of campylobacteriosis per consumed serving of salad contaminated with poultry meat of 4.99 x 10–3 (95% CI: 6.12 x 10–6–1.13 x 10–2), corresponding to an annual incidence risk estimated of 1,876,009 persons. Scenario analysis indicated that the application of vaccines against Campylobacter (probability of campylobacteriosis = 9.55 x 10–4; 95% CI: 5.31 x 10–4–1.29 x 10–3) and the supplementation of broilers with probiotics (probability of campylobacteriosis = 1.32 x 10–3; 8.55 x 10–4–1.69 x 10–3) can offer a modest reduction in risk estimates. The intervention efficacy was 80.86% and 73.54% for vaccination and probiotic supplementation, respectively. On‐farm interventions were effective to mitigate the risk of campylobacteriosis.
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Background: People consume nitrates, nitrites, nitrosamines, and NOCs compounds primarily through processed food. Many studies have yielded inconclusive results regarding the association between cancer and dietary intakes of nitrates and nitrites. This study aimed to quantify these associations across the reported literature thus far. Methods: We performed a systematic review following PRISMA and MOOSE guidelines. A literature search was performed using Web of Science, Embase, PubMed, the Cochrane library, and google scholar up to January 2020. STATA version 12.0 was used to conduct meta-regression and a two-stage meta-analysis. Results: A total of 41 articles with 13 different cancer sites were used for analysis. Of these 13 cancer types/sites, meta-regression analysis showed that bladder and stomach cancer risk was greater, and that pancreatic cancer risk was lower with increasing nitrite intakes. Kidney and bladder cancer risk were both lower with increasing nitrate intakes. When comparing highest to lowest (reference) categories of intake, meta-analysis of studies showed that high nitrate intake was associated with an increased risk of thyroid cancer (OR = 1.40, 95% CI: 1.02, 1.77). When pooling all intake categories and comparing against the lowest (reference) category, higher nitrite intake was associated with an increased risk of glioma (OR = 1.12, 95% CI: 1.03, 1.22). No other associations between cancer risk and dietary intakes of nitrates or nitrites were observed. Conclusion: This study showed varied associations between site-specific cancer risks and dietary intakes of nitrate and nitrite. Glioma, bladder, and stomach cancer risks were higher and pancreatic cancer risk was lower with higher nitrite intakes, and thyroid cancer risk was higher and kidney cancer risk lower with higher nitrate intakes. These data suggest type- and site-specific effects of cancer risk, including protective effects, from dietary intakes of nitrate and nitrite.
Article
Yoga is an Indian philosophy systematized in the Yoga Sutras of Patanjali approximately 2000 years ago as a global life style approach consisting of eight interrelated components. The first component consists of ethical behavior prescriptions toward others (e.g. non-harming) and the second consists of rules of conduct toward the self (e.g. discipline). The third is the practice of physical poses or asana. The fourth is a controlled breathing practice. The fifth consists of controlling sensory input. The following three components are increasingly more advanced levels of meditative practice. Specifically, the sixth component consists of practicing sustained concentration or focused attention on one object. The seventh is a state of absorption in which the entire perceptual flow is directed toward the object. The eighth and final component is a state of integration in which the object is seen as indivisible from the self . The goal of regularly practicing these eight components is to calm the restlessness of the mind so that mental activity can be directed into productive channels and mental pain can be alleviated (Iyengar 1966). Contemporary yoga practices primarily focus on asana, controlled breathing and meditation, with various degrees of emphasis on each of these components (National Center for Complementary and Integrative Health 2016). Yoga incorporating asana, or asana-based yoga, includes traditional practices such as Hatha, Iyengar, Sivananda and Ashtanga.
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Some people report encountering fewer obstacles during goal pursuit than others, but why is this the case? Seven pre-registered studies examine the role of goal motivation (want-to and have-to) and trait self-control in how individuals set up and perceive obstacles to goal pursuit in their environment. Findings show that want-to motivation and trait self-control were associated with reduced experiences of obstacles; have-to motivation was associated with a preference for greater proximity to obstacles. Have-to motivation was also related to stronger perceptions of obstacles as problematic, and trait self-control was related to the perception of obstacles as less problematic. Discussion centers on nuances regarding these relations and their existence in different contexts, and on implications for self-regulation and motivation.
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Little systematic information has been collected about the nature and types of articles published in 2 journals by identifying the latent topics and analyzing the extracted research themes and sentiments using text mining and machine learning within the 2020 time frame. The goals of this study were to conduct a content analysis of articles published in 2 journals, describe the research type, identify possible gaps, and propose future agendas for readers. We downloaded 5610 abstracts in the journals of Medicine (Baltimore) and the Journal of the Formosan Medical Association (JFMA) from the PubMed library in 2020. Sentiment analysis (ie, opinion mining using a natural language processing technique) was performed to determine whether the article abstract was positive or negative toward sentiment to help readers capture article characteristics from journals. Cluster analysis was used to identify article topics based on medical subject headings (MeSH terms) using social network analysis (SNA). Forest plots were applied to distinguish the similarities and differences in article mood and MeSH terms between these 2 journals. The Q statistic and I2 index were used to evaluate the difference in proportions of MeSH terms in journals. The comparison of research topics between the 2 journals using the 737 cited articles was made and found that most authors are from mainland China and Taiwan in Medicine and JFMA, respectively, similarity is supported by observing the abstract mood (Q = 8.3, I2 = 0, P = .68; Z = 0.46, P = .65), 2 journals are in a common cluster (named latent topic of patient and treatment) using SNA, and difference in overall effect was found by the odds ratios of MeSH terms (Q = 185.5 I2 = 89.8, P < .001; Z = 5.93, P < .001) and a greater proportion of COVID-19 articles in JFMA. SNA and forest plots were provided to readers with deep insight into the relationships between journals in research topics using MeSH terms. The results of this research provide readers with a concept diagram for future submissions to a given journal. The main approaches frequently used in Meta-analysis for drawing forest plots contributed to the following: Comparing abstract mood in 2 journals, which is modern and innovative in the literature. Extracting article topics from MeSH terms using SNA, drawing visual representations by using SNA, choropleth map, and forest plots that can inspire other relevant research to replicate the approaches for the other 2 paired journals in comparison of differences in research topics in the future.
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Zu den Aufgaben von Schule gehört, Kindern und Jugendlichen Lerngelegenheiten zu eröffnen, die der Alltag ihnen nicht bietet. Auch im Bereich der Umweltbildung scheint die Schule gefordert, eine solche (kompensatorische) Funktion zu übernehmen. Konzepte und Befunde zur Umweltbildung werden in der vorliegenden Arbeit vor dem Hintergrund von Modellen der Schulqualitätsforschung, mit Blick auf allgemeindidaktische Ansätze sowie in Bezug auf schulische Reformen seit Ende der 1990er Jahre diskutiert. Ausgehend hiervon wird untersucht, in welchem Umfang und in welcher Form neue bzw. erweiterte Gestaltungsfreiräume, die sich z.B. im Kontext der Schulprogrammarbeit ergeben, von Schulen für den Ausbau und die didaktische Weiterentwicklung von Umweltbildungsangeboten (etwa im Sinne einer stärker adaptiven Gestaltung) genutzt werden (könnten). Hierfür stehen Daten aus einer Dokumentenanalyse sowie schriftlichen Befragungen von Schulleitungen, Lehrkräften, Schülerinnen und Schülern zur Verfügung. Das Buch steht in einer elektronischen Version zur Verfügung: https://doi.org/10.17879/84049444480
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Despite the documented efficacy of neurofeedback (NFB) in the treatment of people with anxious symptomatology, many insurance companies identify NFB as experimental, which prohibits individuals from utilizing benefits to obtain this therapeutic treatment. In order to examine this discrepancy, the present meta‐analyses were conducted to examine the overall effectiveness of NFB, examine the impact of participant characteristics, and identify the extent of the differences in anxiety‐spectrum outcomes. Twenty‐six articles were divided based on design (12 single group (SG); 14 between‐group (BG)) and analyzed in separate meta‐analyses. Overall, results indicated that anxiety‐spectrum self‐report assessments were reduced by nearly one (SG SDM= −0.94; BG g = −0.87) standard deviation unit with relatively small degrees of bias. This study reports findings from the first exhaustive search of the literature, which included articles coming from a total of 17 databases/repositories. Applications of the findings are limited to Caucasian adults with symptoms of anxiety or PTSD.
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Using a total of 4,425 estimates collected from 204 previous studies, this paper presents a meta-analysis performed to compare East European EU member states, Russia and China in terms of the relationship between ownership structure and firm performance. The results indicate that, as the standard theory predicts, state ownership negatively influences the performance of firms the state invests in, while the presence of domestic outside investors and foreign investors as company owners positively affects firm performance irrespective of the difference in country/region. Furthermore, we also found that ownership of managers tends to exert a positive impact on the performance of their owned firms. Overall, however, the linkage between corporate ownership and performance is weak. This finding implies that, in comparison with advanced economies, management discipline by investors is less sufficient in emerging markets.
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In many animal species, males may exhibit one of several discrete, alternative ways of obtaining fertilisations, known as alternative reproductive tactics (ARTs). Males exhibiting ARTs typically differ in the extent to which they invest in traits that improve their mating success, or the extent to which they face sperm competition. This has led to the widespread prediction that males exhibiting ARTs associated with a high sperm competition risk, or lower investment into traits that improve their competitiveness before mating, should invest more heavily into traits that improve their competitiveness after mating, such as large ejaculates and high‐quality sperm. However, despite many studies investigating this question since the 1990s, evidence for differences in sperm and ejaculate investment between male ARTs is mixed, and there has been no quantitative summary of this field. Following a systematic review of the literature, we performed a meta‐analysis examining how testes size, sperm number and sperm traits differ between males exhibiting ARTs that face either a high or low sperm competition risk, or high or low investment in traits that increase mating success. We obtained data from 92 studies and 67 species from across the animal kingdom. Our analyses showed that male fish exhibiting ARTs facing a high sperm competition risk had significantly larger testes (after controlling for body size) than those exhibiting tactics facing a low sperm competition risk. However, this effect appears to be due to the inappropriate use of the gonadosomatic index as a body‐size corrected measure of testes investment, which overestimates the difference in testes investment between male tactics in most cases. We found no significant difference in sperm number between males exhibiting different ARTs, regardless of whether sperm were measured from the male sperm stores or following ejaculation. We also found no significant difference in sperm traits between males exhibiting different ARTs, with the exception of sperm adenosine triphosphate (ATP) content in fish. Finally, the difference in post‐mating investment between male ARTs was not influenced by the extent to which tactics were flexible, or by the frequency of sneakers in the population. Overall, our results suggest that, despite clear theoretical predictions, there is little evidence that male ARTs differ substantially in investment into sperm and ejaculates across species. The incongruence between theoretical and empirical results could be explained if (i) theoretical models fail to account for differences in overall resource levels between males exhibiting different ARTs or fundamental trade‐offs between investment into different ejaculate and sperm traits, and (ii) studies often use sperm or ejaculate traits that do not reflect overall post‐mating investment accurately or affect fertilisation success.
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Understanding how consciousness arises from neural activity remains one of the biggest challenges for neuroscience. Numerous theories have been proposed in recent years, each gaining independent empirical support. Currently, there is no comprehensive, quantitative and theory-neutral overview of the field that enables an evaluation of how theoretical frameworks interact with empirical research. We provide a bird’s eye view of studies that interpreted their findings in light of at least one of four leading neuroscientific theories of consciousness (N = 412 experiments), asking how methodological choices of the researchers might affect the final conclusions. We found that supporting a specific theory can be predicted solely from methodological choices, irrespective of findings. Furthermore, most studies interpret their findings post hoc, rather than a priori testing critical predictions of the theories. Our results highlight challenges for the field and provide researchers with an open-access website (https://ContrastDB.tau.ac.il) to further analyse trends in the neuroscience of consciousness. Yaron and colleagues collected and classified 412 experiments relating to four leading theories in consciousness research, providing a comprehensive overview of the field and unravelling trends and methodological biases.
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Abstract Purpose This study was conducted to systematically examine the effect of decision support systems (DSSs) applied to patients with cancer on pain severity. Review methods Systematic review and meta-analysis. A search was done on Web of Science, Science Direct, PubMed, ProQuest, EBSCOhost/CINAHL Complete, Scopus, Springer Link, Cochrane Library, and Ovid databases, which covered a period until September 2021. Meta-analysis of the data was conducted on the CMA 3 software package. Comprehensive reviews were conducted by two independent researchers in line with the PICOS criteria. The study was conducted according to the PRISMA checklist. Findings Five randomized controlled trials with 1.880 participants were included in this systematic review and meta-analysis. In the study, visits, consultations, simulation of patient outcomes, telephone support, and email applications were employed for periods ranging from 6 weeks to 6 months. The evaluation of the meta-analysis results indicated that DSSs had positive effects on pain severity in patients with cancer (Hedge's g = 0.22; p < 0.001). Conclusion The findings of this systematic review and meta-analysis show that DSSs can be used as an effective and comfortable technological application in reducing the severity of pain in patients with cancer. Clinical relevance The use of DSSs for pain severity in patients with cancer is an effective method. In line with the findings of this systematic review and meta-analysis, awareness and knowledge levels of all health disciplines about DSSs will increase. It is believed that the use of DSSs to improve patient-centered care will be guiding.
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Osteoporosis is a major health issue worldwide. This study analyzes the effects of non-supervised osteoporosis prevention programs on bone mineral density. Non-supervised exercise increases femoral neck and lumbar spine bone mineral density in adult women. Thus, it might be effective for preventing or treating osteoporosis or osteopenia in this population. Introduction: Osteoporosis is a major health issue worldwide. Social distancing measures due to COVID-19 have hindered the chances to take part in supervised osteoporosis prevention exercise programs. The purpose of the present study is to systematically review and meta-analyze the effects of non-supervised osteoporosis prevention exercise programs on bone mineral density (BMD) in adult women. Methods: A comprehensive search of electronic databases (n = 7) was conducted including (a) prospective randomized controlled trials (RCTs) comparing at least one exercise group vs. a control group with sedentary lifestyle or sham exercises; (b) baseline and follow-up BMD values, or BMD changes from baseline, at any skeletal site; (c) women over 30 years old; and (d) non-supervised exercise programs only. Subgroup analyses were performed for menopausal status, intervention duration, type of exercise, and osteopenia/osteoporosis status. Results: Ten studies were included (n = 668). Random effect analyses showed that unsupervised exercise had beneficial effects on lumbar spine (LS) BMD with standardized mean difference (SMD) = 0.40 (95% confidence interval (CI): 0.03-0.77), and femoral neck (FN) BMD with SMD = 0.51 (95% CI: 0.16-0.85). Unsupervised exercise increased LS (SMD = 0.73 (95% CI: 0.13-1.33)) and FN BMD (SMD = 0.85 (95% CI: 0.33-1.37)) in women with osteopenia/osteoporosis, but not in healthy counterparts. Conclusion: Non-supervised exercise improves FN and LS BMD in adult women. Beneficial effects of exercise on FN and LS BMD might be more pronounced in those with poor bone health compared with healthy counterparts. More RCTs prescribing non-supervised, osteogenic exercise are required in this population. It is necessary to investigate the efficacy of remote/assistive technologies for delivering and monitoring non-supervised exercise interventions.
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Background: Much confusion exists about the underachievement of gifted students due to significant variations in how the phenomenon has been identified. From a review of the literature, five methods were found to be commonly used to identify gifted underachievement. Aims: The purpose of the study was to assess the equivalence of the commonly used methods to identify gifted underachievement, and to determine which of these methods may be optimal. Sample: Data were collected from a school in Sydney, Australia. Method: Three measures of convergence (i.e., difference in proportions, phi association, and kappa agreement) were used to assess the equivalence of the identification methods, while latent class analysis was used to determine the optimal identification method. Results: The convergence evidence suggested that the commonly used identification methods may not be considered convergent, while the criterion evidence indicated that one of the five identification methods may have strong levels of criterion validity. Conclusions: A conclusion was reached that the simple difference method may be the most valid method to identify gifted underachievement.
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Previous meta‐analyses have shown that feedback targeting text comprehension given when students perform a reading task positively influences learning from text. So far, differences in the effects of feedback were explained by design features, such as the timing and richness of feedback. In the present study, we aim to investigate cognitive and affective processes that might be triggered by feedback targeting text comprehension. Two meta‐analyses were performed on feedback intervention studies that included statistics for both the effect of feedback targeting text comprehension on the use of reading strategies (k = 8) or readers' attitudes towards the reading task (k = 10) and the effect of feedback on reading comprehension. We first tested whether feedback significantly affected the use of reading strategies or readers' attitudes. We then performed a meta‐regression analysis to test if the magnitude of the effect significantly predicted gains in reading comprehension. Feedback targeting text comprehension had a positive and significant impact on the use of reading strategies (g+ = 0.61) and on reading comprehension (g+ = 0.34). Additionally, the magnitude of the effect on the use of reading strategies was positively related to the magnitude of the effect on reading comprehension. Feedback targeting text comprehension did not influence readers' attitudes towards the reading task. Also, no significant effect of feedback was found for reading comprehension in these studies. Feedback targeting text comprehension helps students to apply reading strategies more often and/or more efficiently, even when they read new texts without the help of feedback. This transfer of practiced reading strategies in turn fosters reading comprehension. Due to the scarce number of studies, the results of the present meta‐analysis should be interpreted as an incentive for the field of reading research to unify empirical approaches for the integrated study of affective processes triggered by feedback targeting text comprehension. What is already known about this topic Feedback that targets text comprehension has, on average, been shown to positively influence reading comprehension. However, study heterogeneity is high. Different design features of feedback, such as the richness and timing of the feedback, only partially explain the variance in effects. What this paper adds Feedback targeting text comprehension has a positive effect on the use of reading strategies, even when reading new texts without the help of feedback. The strength of this effect in turn predicts gains in reading comprehension. The currently available studies show no effect of feedback targeting text comprehension on readers' attitudes towards the reading task; however, studies on this topic are scarce and divergent, making this conclusion tentative. Implications for theory, policy or practice Feedback during reading that targets text comprehension can be used as an effective instructional tool to enhance the use of reading strategies and, consequently, to improve reading comprehension. Future research on how to effectively use feedback in reading instruction should distinguish two different perspectives: feedback as a tool to facilitate text comprehension ‘on the job’ and feedback as a tool to teach reading strategies that facilitate text comprehension. The current meta‐analysis shows that the effects of feedback that targets text comprehension on reading attitude or reading motivation are understudied. Secondly, operationalisations of attitudinal and motivational variables in the scarce studies on this topic diverge, hindering interpretation of the available results. Strong research programmes that unify empirical approaches for studying the effects of feedback targeting text comprehension on readers' attitudes and other motivational factors are needed.
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Individual participant data meta‐analysis is a frequently used method to combine and contrast data from multiple independent studies. Bayesian hierarchical models are increasingly used to appropriately take into account potential heterogeneity between studies. In this paper, we propose a Bayesian hierarchical model for individual participant data generated from the Cigarette Purchase Task (CPT). Data from the CPT details how demand for cigarettes varies as a function of price, which is usually described as an exponential demand curve. As opposed to the conventional random‐effects meta‐analysis methods, Bayesian hierarchical models are able to estimate both the study‐specific and population‐level parameters simultaneously without relying on the normality assumptions. We applied the proposed model to a meta‐analysis with baseline CPT data from six studies and compared the results from the proposed model and a two‐step conventional random‐effects meta‐analysis approach. We conducted extensive simulation studies to investigate the performance of the proposed approach and discussed the benefits of using the Bayesian hierarchical model for individual participant data meta‐analysis of demand curves.
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Introduction: Decades of research show an association between alcohol use and death by suicide. However, findings on the temporal link between alcohol use and death by suicide are unclear. In the most comprehensive meta-analysis on the topic to date, we analyzed data from longitudinal studies to determine if alcohol use is a risk for death by suicide. We also explored moderators to uncover conditions where the alcohol use-suicide link is strengthened/weakened. Methods: Our literature search of six databases yielded 33 eligible studies involving 10,253,101 participants (community, psychiatric, and military samples). Results: Alcohol use was associated with a 94% increase in the risk of death by suicide. Specifically, random-effects meta-analysis revealed alcohol use displayed small-to-large significant risk and odds ratios with suicide for quantity of alcohol use and alcohol use diagnosis/alcohol-related problems. Meta-regression generally indicated larger effect sizes for studies with a higher percentage of women, younger age, unadjusted estimates, longer follow-up periods, military samples, and higher frequencies and quantities of alcohol use (relative to drinker/non-drinker status). Conclusion: Our study highlights alcohol use as a substantive risk factor for death by suicide and underscores the importance of monitoring alcohol use among suicidal individuals and screening for suicidality among heavier alcohol users.
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Background High-intensity interval training (HIIT) has shown to confer cognitive benefits in healthy adults, via a mechanism purportedly driven by the exercise metabolite lactate. However, our understanding of the exercise parameters (e.g., work interval duration, session volume, work-to-rest ratio) that evoke a peak blood lactate response in healthy adults is limited. Moreover, evidence relating HIIT-induced blood lactate and cognitive performance has yet to be reviewed and analyzed. The primary objective of this systematic review is to use network meta-analyses to compare the relative impact of different HIIT work-interval durations, session volumes, and work-to-rest ratios on post-exercise blood lactate response in healthy adults. The secondary objective is to determine the relationship between HIIT-induced blood lactate and acute post-HIIT cognitive performance. Methods A systematic review is being conducted to identify studies measuring blood lactate response following one session of HIIT in healthy adults. The search was carried out in (1) MEDLINE, (2) EMBASE, (3) Cochrane Central Register of Controlled Trials, (4) Sport Discus, and (5) Cumulative Index to Nursing and Allied Health Literature Plus with Full Text (CINAHL+). After abstract and full-text screening, two reviewers will independently extract data on key outcomes variables and complete risk of bias assessment using the Cochrane Risk of Bias Tool and the Risk of Bias in Non-Randomized Studies of Interventions tool. Network meta-analyses will be used to generate estimates of the comparative effectiveness of blood lactate on cognitive outcomes using corresponding rankings for each work-interval duration, session volume, and work-to-rest ratio category. Where applicable, meta-regressions analyses will be performed to test the relationship between changes in the blood lactate and changes in cognitive performance. Analyses will be conducted using MetaInsight Software. Discussion This study will provide evidence on how to structure a HIIT protocol to elicit peak blood lactate response in healthy adults and will increase our understanding of the relationship between HIIT-induced blood lactate response and associated cognitive benefits. Systematic review registration PROSPERO CRD42020204400
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