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The design and reporting of safety outcomes in MMR vaccine studies, both pre- and post-marketing, are largely inadequate. The evidence of adverse events following immunisation with the MMR vaccine cannot be separated from its role in preventing the target diseases.

Background Mumps, measles and rubella (MMR) are serious diseases that can lead to potentially fatal illness, disability and death. However, public debate over the safety of the trivalent MMR vaccine and the resultant drop in vaccination coverage in several countries persists, despite its almost universal use and accepted effectiveness. Objectives To assess the effectiveness and adverse effects associated with the MMR vaccine in children up to 15 years of age. Search methods For this update we searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2011, Issue 2), which includes the Cochrane Acute Respiratory Infections Group's Specialised Register, PubMed (July 2004 to May week 2, 2011) and Embase.com (July 2004 to May 2011). Selection criteria We used comparative prospective or retrospective trials assessing the effects of the MMR vaccine compared to placebo, do nothing or a combination of measles, mumps and rubella antigens on healthy individuals up to 15 years of age. Data collection and analysis Two review authors independently extracted data and assessed methodological quality of the included studies. One review author arbitrated in case of disagreement. Main results We included five randomised controlled trials (RCTs), one controlled clinical trial (CCT), 27 cohort studies, 17 case‐control studies, five time‐series trials, one case cross‐over trial, two ecological studies, six self controlled case series studies involving in all about 14,700,000 children and assessing effectiveness and safety of MMR vaccine. Based on the available evidence, one MMR vaccine dose is at least 95% effective in preventing clinical measles and 92% effective in preventing secondary cases among household contacts. Effectiveness of at least one dose of MMR in preventing clinical mumps in children is estimated to be between 69% and 81% for the vaccine prepared with Jeryl Lynn mumps strain and between 70% and 75% for the vaccine containing the Urabe strain. Vaccination with MMR containing the Urabe strain has demonstrated to be 73% effective in preventing secondary mumps cases. Effectiveness of Jeryl Lynn containing MMR in preventing laboratory‐confirmed mumps cases in children and adolescents was estimated to be between 64% to 66% for one dose and 83% to 88% for two vaccine doses. We did not identify any studies assessing the effectiveness of MMR in preventing rubella. The highest risk of association with aseptic meningitis was observed within the third week after immunisation with Urabe‐containing MMR (risk ratio (RR) 14.28; 95% confidence interval (CI) from 7.93 to 25.71) and within the third (RR 22.5; 95% CI 11.8 to 42.9) or fifth (RR 15.6; 95% CI 10.3 to 24.2) weeks after immunisation with the vaccine prepared with the Leningrad‐Zagreb strain. A significant risk of association with febrile seizures and MMR exposure during the two previous weeks (RR 1.10; 95% CI 1.05 to 1.15) was assessed in one large person‐time cohort study involving 537,171 children aged between three months and five...

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Objective To explore the relation between study concordance, take home message, funding, and dissemination of comparative studies assessing the effects of influenza vaccines.Design Systematic review without meta-analysis.Data extraction 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. Data synthesisWe 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.Conclusion Publication in prestigious journals is associated with partial or total industry funding, and this association is not explained by study quality or size. INTRODUCTIONHealthcare workers wanting to keep up to date with recent advances in their specialty must deal with the quantity and quality of information sources. 1 2 One study estimated that every month journals publish 7287 items (studies, letters, and editorials) relevant to primary care. These would take physicians trained in epidemiology 627 hours to read and appraise. Few healthcare workers have the time and skills to carry out in depth critical appraisal of published articles.3 Given the pressures of everyday work, the time available for reading a scientific article might be as little as 22 minutes. 4To inform their conduct and update their knowledge physicians might rely on a brief (two minute) scan of material.5 6 This probably includes either browsing the abstract (the "shop window" of an article) or the conclusions paragraph (the "take home message"), especially those published in prestigious journals (that is, those with the highest journal impact factor) that are most readily available or of their digests. The impact factor was specifically developed to facilitate prioritisation of subscription resources, allowing targeting on the most cited journals, considered to be most read and the ones that publish articles of the best quality. These journals are thus more likely to be accessible and their content widely disseminated. 8Methodological quality of studies is the other important aspect. Several items, all affecting the reliability of what presents to healthcare workers, are relate...