How to Conduct and Interpret Systematic Reviews and Meta-Analyses.

Systematic reviews with or without meta-analyses serve a key purpose in critically and objectively synthesizing all available evidence regarding a focused clinical question and can inform clinical practice and clinical guidelines. Performing a rigorous systematic review is multi-step process, which includes (a) identifying a well-defined focused clinically relevant question, (b) developing a detailed review protocol with strict inclusion and exclusion criteria, (c) systematic literature search of multiple databases and unpublished data, in consultation with a medical librarian, (d) meticulous study identification and (e) systematic data abstraction, by at least two sets of investigators independently, (f) risk of bias assessment, and (g) thoughtful quantitative synthesis through meta-analysis where relevant. Besides informing guidelines, credible systematic reviews and quality of evidence assessment can help identify key knowledge gaps for future studies.