What is the difference between a "systematic review" and a "meta-analysis"?
A systematic review is a thorough, comprehensive, and explicit way of interrogating the medical literature. It typically involves several steps, including (1) asking an answerable question (often the most difficult step), (2) identifying one or more databases to search, (3) developing an explicit search strategy, (4) selecting titles, abstracts, and manuscripts based on explicit inclusion and exclusion criteria, and (5) abstracting data in a standardized format.
A "meta-analysis" is a statistical approach to combine the data derived from a systematic-review. Therefore, every meta-analysis should be based on an underlying systematic review, but not every systematic review leads to a meta-analysis.