What is a systematic review?
Definition #1: It is a review of the evidence on a clearly formulated question that uses systematic and explicit methods to identify, select, and critically appraise relevant primary research studies, and to extract and analyze data from the studies included in the review. If a meta-analysis follows, the systematic review provides the data needed for the meta-analysis.
Definition #2: It is a rigorous review of the literature in which your goal is to find all studies conducted on a given research topic.
What is a meta-analysis?
It is the use of statistical techniques to combine the results of quantitative research studies addressing the same question into a summary measure. If a meta-analysis is done, a systematic review has to precede it.
Importance for Health Care
Systematic reviews done with or without meta-analyses aim to identify, evaluate, and summarize the findings of all relevant individual studies on a health-related issue, thereby making the available evidence more accessible to decision makers, to include clinicians, administrators, and healthcare policy makers.
Systematic reviews and meta-analyses are conducted primarily in the clinical sciences, psychology, and public health but are becoming used more often in the biological, physical, and other social sciences.