Abstract
Synthesis of research findings has long been a part of reviewing and summarizing a field of study. Public health decisions are made on the available evidence. We summarize the approaches to research synthesis that draw on the best available evidence and the use of quantitative summaries through meta-analysis. We focus on observational studies. Heterogeneity offers the potential to observe a relation across study populations and circumstances. We emphasize the benefits of heterogeneity in overviews and the need to explore and describe the sources of heterogeneity. Random effects approaches to combining data are recommended, and the use of regression approaches is emphasized. Excluding studies with extreme results may bias a research synthesis and underestimate the true variance of the results, thus contributing to misleading inference. Thorough searching is the best guard against publication bias. We conclude with guidelines for combining epidemiological studies.
Keywords
Related Publications
Arcsine test for publication bias in meta‐analyses with binary outcomes
Abstract In meta‐analyses, it sometimes happens that smaller trials show different, often larger, treatment effects. One possible reason for such ‘small study effects’ is public...
Random-Effects Meta-Analyses Are Not Always Conservative
It is widely held that random-effects summary effect estimates are more conservative than fixed-effects summaries in epidemiologic meta-analysis. This view is based on the fact ...
Explaining heterogeneity in meta-analysis: a comparison of methods
Exploring the possible reasons for heterogeneity between studies is an important aspect of conducting a meta-analysis. This paper compares a number of methods which can be used ...
Assessing Publication Bias in Meta-Analyses in the Presence of Between-Study Heterogeneity
Summary Between-study heterogeneity and publication bias are common features of a meta-analysis that can be present simultaneously. When both are suspected, consideration must b...
Corticosteroids as Adjunctive Therapy in the Treatment of Influenza: An Updated Cochrane Systematic Review and Meta-analysis
Objectives: Corticosteroids may be beneficial in sepsis, but uncertainty remains over their effects in severe influenza. This systematic review updates the current evidence rega...
Publication Info
- Year
- 1996
- Type
- review
- Volume
- 17
- Issue
- 1
- Pages
- 1-23
- Citations
- 229
- Access
- Closed
External Links
Social Impact
Social media, news, blog, policy document mentions
Citation Metrics
Cite This
Identifiers
- DOI
- 10.1146/annurev.pu.17.050196.000245