Objective: To assess the validity of a meta-analysis about sclerotherapy for the primary prevention of bleeding from esophageal varices, to interpret the results, and discuss whether they apply in practice.
Data sources: Critical appraisal techniques for systematic reviews.
Data extraction: Systematic reviews are distinct from narrative reviews in that they answer specific clinical questions, and have explicit and reproducible methods for searching, selecting, and appraising the primary studies, to create the most valid synthesis of the evidence.
Data synthesis: Meta-analyses are systematic reviews containing a critical appraisal and statistical summary of individual study results and their confidence limits, whereas qualitative systematic reviews provide a narrative executive summary of study results.
Conclusions: High-quality systematic reviews are being used increasingly to guide practice, strengthening the link between research results and improved health outcomes. Understanding their strengths and limitations helps us to use them appropriately in practice.