The quality of a systematic review / Meta-analysis depends to some extent on which original studies are included, and how the data in the original studies are extracted, analyzed, and presented. This article will introduce how to identify different publications of the same research during screening, how to determine whether a research is a target research from simple to complex levels, and how to review exclusion studies one by one. The data extraction process should be objective, require prior training, pre-extraction, multiple people extraction, and reasonable treatment of the differences that arise. The data extraction table is the core and soul of the data extraction process. Reasonably designing the data extraction table and appropriate data conversion when necessary is a sufficient condition for a qualified systematic review. This article will elaborate the specific strategies and methods for data extraction after the target research is determined from these aspects.

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