Evaluating the validity of a Systematic Review
Are the results of this article valid?
1. Did the review explicitly address a sensible question?
The systematic review should address a specific question that indicates the patient problem, the exposure and one or more outcomes. General reviews, which usually do not address specific questions, may be too broad to provide an answer to the clinical question for which you are seeking information.
2. Was the search for relevant studies detailed and exhaustive?
Researchers should conduct a thorough search of appropriate bibliographic databases. The databases and search strategies should be outlined in the methodology section. Researchers should also show evidence of searching for non-published evidence by contacting experts in the field. Cited references at the end of articles should also be checked.
3. Were the primary studies of high methodological quality?
Researchers should evaluate the validity of each study included in the systematic review. The same EBP criteria used to critically appraise studies should be used to evaluate studies to be included in the systematic review. Differences in study results may be explained by differences in methodology and study design.
4. Were selection and assessments of the included studies reproducible?
More than one researcher should evaluate each study and make decisions about its validity and inclusion. Bias (systematic errors) and mistakes (random errors) can be avoided when judgment is shared. A third reviewer should be available to break a tie vote.
|Key issues for Systematic Reviews:
- focused question
- thorough literature search
- include validated studies
- selection of studies reproducible