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How-to develop a Literature Review

Systematic reviews vs. Meta-Analysis

Systematic review or meta-analysis?

systematic review answers a defined research question by collecting and summarizing all empirical evidence that fits pre-specified eligibility criteria.

meta-analysis is the use of statistical methods to summarize the results of these studies.

Systematic reviews, just like other research articles, can be of varying quality. They are a significant piece of work (the Centre for Reviews and Dissemination at York estimates that a team will take 9-24 months), and to be useful to other researchers and practitioners they should have:

  • clearly stated objectives with pre-defined eligibility criteria for studies
  • explicit, reproducible methodology
  • a systematic search that attempts to identify all studies
  • assessment of the validity of the findings of the included studies (e.g. risk of bias)
  • systematic presentation, and synthesis, of the characteristics and findings of the included studies

Not all systematic reviews contain meta-analysis. 


Meta-analysis is the use of statistical methods to summarize the results of independent studies. By combining information from all relevant studies, meta-analysis can provide more precise estimates of the effects of health care than those derived from the individual studies included within a review.  More information on meta-analyses can be found in Cochrane Handbook, Chapter 9.

meta-analysis goes beyond critique and integration and conducts secondary statistical analysis on the outcomes of similar studies.  It is a systematic review that uses quantitative methods to synthesize and summarize the results.

An advantage of a meta-analysis is the ability to be completely objective in evaluating research findings.  Not all topics, however, have sufficient research evidence to allow a meta-analysis to be conducted.  In that case, an integrative review is an appropriate strategy. 

Some of the content in this section is from Systematic reviews and meta-analyses: step by step guide created by Kate McAllister.