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Concept: Review journal


There is burgeoning interest in augmentation strategies for improving inadequate response to antidepressants. The adjunctive use of standardized pharmaceutical-grade nutrients, known as nutraceuticals, has the potential to modulate several neurochemical pathways implicated in depression. While many studies have been conducted in this area, to date no specialized systematic review (or meta-analysis) has been conducted.

Concepts: Nutrition, Evidence-based medicine, Systematic review, Meta-analysis, Review journal


Objective To investigate whether the success rate of retrieving individual participant data (IPD) for use in IPD meta-analyses has increased over time, and to explore the characteristics associated with IPD retrieval.Design Systematic review of published IPD meta-analyses, supplemented by a reflection of the Cochrane Epilepsy Group’s 20 years' experience of requesting IPD.Data sources Medline, CENTRAL, Scopus, Web of Science, CINAHL Plus, and PsycINFO.Eligibility criteria for study selection IPD meta-analyses of studies of all designs and all clinical areas published in English.Results 760 IPD meta-analyses which identified studies by systematic methods that had been published between 1987 and 2015 were included. Only 188 (25%) of these IPD meta-analyses retrieved 100% of the eligible IPD for analysis, with 324 (43%) of these IPD meta-analyses retrieving 80% or more of relevant IPD. There is insufficient evidence to suggest that IPD retrieval rates have improved over time. IPD meta-analyses that included only randomised trials, had an authorship policy, included fewer eligible participants, and were conducted outside of the Cochrane Database of Systematic Reviews were associated with a high or complete IPD retrieval rate. There was no association between the source of funding of the IPD meta-analyses and IPD retrieval rate. The IPD retrieval rate of the Cochrane Epilepsy Group has declined from 83% (up to 2005) to 65% (between 2012 and 2015) and the reported reasons for lack of data availability have changed in recent years.Conclusions IPD meta-analyses are considered to be the “gold standard” for the synthesis of data from clinical research studies; however, only 25% of published IPD meta-analyses have had access to all IPD.

Concepts: Medicine, Evidence-based medicine, Systematic review, Randomized controlled trial, Clinical research, Meta-analysis, Review journal, Critical appraisal


Food industry sponsorship of nutrition research may bias research reports, systematic reviews, and dietary guidelines.

Concepts: Nutrition, Evidence-based medicine, Systematic review, Food, Review, Meta-analysis, Review journal, Food industry


Findings from systematic reviews and meta-analyses about the effectiveness of school-based programmes to prevent or reduce substance abuse are inconclusive. We hypothesise that in order to be effective, programmes have to be aligned with the developmental stages of the intended target group (childhood, early, middle, or late adolescence). The present study provides an overview of universal and targeted programmes, while distinguishing four age groups and examining which intervention characteristics are the effective components for the respective groups.

Concepts: Evidence-based medicine, Systematic review, Effectiveness, Addiction, Adolescence, Meta-analysis, Review journal, Preadolescence


 For any health intervention, accurate knowledge of both benefits and harms is needed. Systematic reviews often compound poor reporting of harms in primary studies by failing to report harms or doing so inadequately. While the PRISMA statement (Preferred Reporting Items for Systematic reviews and Meta-Analyses) helps systematic review authors ensure complete and transparent reporting, it is focused mainly on efficacy. Thus, a PRISMA harms checklist has been developed to improve harms reporting in systematic reviews, promoting a more balanced assessment of benefits and harms.

Concepts: Medicine, Evaluation, Evidence-based medicine, Systematic review, Randomized controlled trial, Report, Meta-analysis, Review journal


Mass media campaigns are frequently used to influence the health behaviors of various populations. There are currently no quantitative meta-analyses of the effect of mass media campaigns on physical activity in adults.

Concepts: Epidemiology, Evidence-based medicine, Systematic review, Effect size, Meta-analysis, Media, Review journal, Mass media


Background and objectiveWalking and cycling have shown beneficial effects on population risk of all-cause mortality (ACM). This paper aims to review the evidence and quantify these effects, adjusted for other physical activity (PA).Data sourcesWe conducted a systematic review to identify relevant studies. Searches were conducted in November 2013 using the following health databases of publications: Embase (OvidSP); Medline (OvidSP); Web of Knowledge; CINAHL; SCOPUS; SPORTDiscus. We also searched reference lists of relevant texts and reviews.Study eligibility criteria and participantsEligible studies were prospective cohort design and reporting walking or cycling exposure and mortality as an outcome. Only cohorts of individuals healthy at baseline were considered eligible.Study appraisal and synthesis methodsExtracted data included study population and location, sample size, population characteristics (age and sex), follow-up in years, walking or cycling exposure, mortality outcome, and adjustment for other co-variables. We used random-effects meta-analyses to investigate the beneficial effects of regular walking and cycling.ResultsWalking (18 results from 14 studies) and cycling (8 results from 7 studies) were shown to reduce the risk of all-cause mortality, adjusted for other PA. For a standardised dose of 11.25 MET.hours per week (or 675 MET.minutes per week), the reduction in risk for ACM was 11% (95% CI =4 to 17%) for walking and 10% (95% CI =6 to 13%) for cycling. The estimates for walking are based on 280,000 participants and 2.6 million person-years and for cycling they are based on 187,000 individuals and 2.1 million person-years. The shape of the dose¿response relationship was modelled through meta-analysis of pooled relative risks within three exposure intervals. The dose¿response analysis showed that walking or cycling had the greatest effect on risk for ACM in the first (lowest) exposure interval.Conclusions and implicationsThe analysis shows that walking and cycling have population-level health benefits even after adjustment for other PA. Public health approaches would have the biggest impact if they are able to increase walking and cycling levels in the groups that have the lowest levels of these activities.Review registrationThe review protocol was registered with Prospero (International database of prospectively registered systematic reviews in health and social care) PROSPERO 2013: CRD42013004266.

Concepts: Health care, Cohort study, Medicine, Epidemiology, Evidence-based medicine, Systematic review, Meta-analysis, Review journal


This study is to perform a systematic review of existing guidance on quality of reporting and methodology for systematic reviews of diagnostic test accuracy (DTA) in order to compile a list of potential items that might be included in a reporting guideline for such reviews: Preferred Reporting Items for Systematic Reviews and Meta-Analyses of Diagnostic Test Accuracy (PRISMA-DTA).

Concepts: Evaluation, Evidence-based medicine, Systematic review, Review, Meta-analysis, Review journal, Review websites, Diagnostic test


Systematic reviews of the literature occupy the highest position in currently proposed hierarchies of evidence. The aims of this study were to assess whether citation classics exist in published systematic review and meta-analysis (SRM), examine the characteristics of the most frequently cited SRM articles, and evaluate the contribution of different world regions.

Concepts: Evidence-based medicine, Systematic review, Randomized controlled trial, Educational psychology, Writing, Meta-analysis, Review journal, Critical appraisal


Glutamine (GLN) has been suggested to have a beneficial influence on outcomes of critically ill patients. However, recent large-scale trials have suggested harm associated with GLN supplementation. Recently, systematic reviews on the use of parenteral GLN have been published; however, less information is available on the role of enteral GLN. Therefore, the aim of this systematic review was to study the effects of enteral GLN supplementation in patients with critical illness.

Concepts: Medicine, Epidemiology, Patient, Evidence-based medicine, Systematic review, Illness, Meta-analysis, Review journal