Relation of study quality, concordance, take home message, funding, and impact in studies of influenza vaccines: systematic review

Cochrane Vaccines Field, ASL (Azienda Sanitaria Locale) AL 20, 15100 Alessandria, Italy.
BMJ (online) (Impact Factor: 17.45). 02/2009; 338(feb12 2):b354. DOI: 10.1136/bmj.b354
Source: PubMed

ABSTRACT To explore the relation between study concordance, take home message, funding, and dissemination of comparative studies assessing the effects of influenza vaccines.
Systematic review without meta-analysis.
Search of the Cochrane Library, PubMed, Embase, and the web, without language restriction, for any studies comparing the effects of influenza vaccines against placebo or no intervention. Abstraction and assessment of quality of methods were carried out.
We identified 259 primary studies (274 datasets). Higher quality studies were significantly more likely to show concordance between data presented and conclusions (odds ratio 16.35, 95% confidence interval 4.24 to 63.04) and less likely to favour effectiveness of vaccines (0.04, 0.02 to 0.09). Government funded studies were less likely to have conclusions favouring the vaccines (0.45, 0.26 to 0.90). A higher mean journal impact factor was associated with complete or partial industry funding compared with government or private funding and no funding (differences between means 5.04). Study size was not associated with concordance, content of take home message, funding, and study quality. Higher citation index factor was associated with partial or complete industry funding. This was sensitive to the exclusion from the analysis of studies with undeclared funding.
Publication in prestigious journals is associated with partial or total industry funding, and this association is not explained by study quality or size.

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Available from: Carlo Di Pietrantonj, Sep 28, 2015
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    • "Distorted reporting in abstracts is of particular concern as these sections are easily accessed (and freely available), so clinical decisions may be based on abstracts alone [24]. Even when the full report is available, readers may only scan the abstract and conclusions [12,25]. These issues are of particular relevance in wound care, an area of healthcare where many of the treatment decisions are made by nurses working in community settings, where there are significant time constraints and limited access to computers and research findings. "
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    ABSTRACT: Spin in the reporting of randomized controlled trials, where authors report research in a way that potentially misrepresents results and mislead readers, has been demonstrated in the broader medical literature. We investigated spin in wound care trials with (a) no statistically significant result for the primary outcome and (b) no clearly specified primary outcome. We searched the Cochrane Wounds Group Specialised Register of Trials for randomized controlled trials (RCTs). Eligible studies were: Parallel-group RCTs of interventions for foot, leg or pressure ulcers published in 2004 to 2009 (inclusive) with either a clearly identified primary outcome for which there was a statistically non-significant result (Cohort A) or studies that had no clear primary outcome (Cohort B).We extracted general study details. For both Cohorts A and B we then assessed for the presence of spin. For Cohort A we used a pre-defined process to assess reports for spin. For Cohort B we aimed to assess spin by recording the number of positive treatment effect claims made. We also compared the number of statistically significant and non-significant results reported in the main text and the abstract looking specifically for spin in the form of selective outcome reporting. Of the 71 eligible studies, 28 were eligible for Cohort A; of these, 71% (20/28) contained spin. Cohort B contained 43 studies; of these, 86% (37/43) had abstracts that claimed a favorable treatment claim. Whilst 74% (32/43) of main text results in Cohort B included at least one statistically non-significant result, this was not reflected in the abstract where only 28% contained (12/43) at least one statistically non-significant result. Spin is a frequent phenomenon in reports of RCTs of wound treatments. Studies without statistically significant results for the primary outcome used spin in 71% of cases. Furthermore, 33% (43/132) of reports of wound RCTs did not specify a primary outcome and there was evidence of spin and selective outcome reporting in the abstracts of these. Readers should be wary of only reading the abstracts of reports of RCTs of wound treatments since they are frequently misleading regarding treatment effects.
    Trials 11/2013; 14(1):371. DOI:10.1186/1745-6215-14-371 · 1.73 Impact Factor
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    • "Vaccination did not have a statistically significant effect on hospitalization or complications, and no evidence was found that vaccines prevent viral transmission. As the review included industry funded trials, the authors found it necessary to include a warning as to the interpretation of its content, stressing that the association between industry funding and study conclusions and publication, as demonstrated in a systematic review of studies on the effect of influenza vaccines [8], could have biased their results and that reliable evidence on influenza vaccines is thin but there is evidence of widespread manipulation of conclusions and spurious notoriety of the studies. The reviewers suggest that although serious harm from vaccination may be rare it cannot be ignored and conclude that the results of their literature review discourage the utilization of vaccination against influenza in healthy adults as a routine measure. "
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    ABSTRACT: Background and Methods. Vaccination of all healthcare workers is widely recommended by health authorities and medical institutions and support for mandatory vaccination is increasing. This paper presents the relevant literature and examines the evidence for patient benefit from healthcare worker vaccination. Articles identified by Medline searches and citation lists were inspected for internal and external validity. Emphasis was put on RCTs. The literature on self-protection from vaccination is also presented. Results. Published research shows that personal benefit from vaccinating healthy nonelderly adults is small and there is no evidence that it is any different for HCWs. The studies aiming to prove the widespread belief that healthcare worker vaccination decreases patient morbidity and mortality are heavily flawed and the recommendations for vaccination biased. No reliable published evidence shows that healthcare workers' vaccination has substantial benefit for their patients—not in reducing patient morbidity or mortality and not even in increasing patient vaccination rates. Conclusion. The arguments for uniform healthcare worker influenza vaccination are not supported by existing literature. The decision whether to get vaccinated should, except possibly in extreme situations, be that of the individual healthcare worker, without legal, institutional, or peer coercion.
    11/2012; 2012:205464. DOI:10.1155/2012/205464
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    • "In a survey of faculty at top U.S. medical research institutions, Tereskerz et al. (2009) found over two-thirds of researchers (338 out of 506) received some support from industry. Studies show that the financial interests of researchers are positively associated with outcomes favorable to the sponsor in medical studies (Friedman and Richter, 2004; Jefferson et al., 2009; Yank et al., 2007). Not only individual researchers, but also research institutions can be influenced by industry sponsorships such as grants, endowed chairs, and other gifts (Tereskerz, 2003). "
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    ABSTRACT: Conflicts of interest (COIs) cloud vaccine safety research. Sponsors of research have competing interests that may impede the objective study of vaccine side effects. Vaccine manufacturers, health officials, and medical journals may have financial and bureaucratic reasons for not wanting to acknowledge the risks of vaccines. Conversely, some advocacy groups may have legislative and financial reasons to sponsor research that finds risks in vaccines. Using the vaccine-autism debate as an illustration, this article details the conflicts of interest each of these groups faces, outlines the current state of vaccine safety research, and suggests remedies to address COIs. Minimizing COIs in vaccine safety research could reduce research bias and restore greater trust in the vaccine program.
    Accountability in Research Policies and Quality Assurance 03/2012; 19(2):65-88. DOI:10.1080/08989621.2012.660073 · 0.83 Impact Factor
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