Through systematic and clear methods to collect, select and evaluate relevant original clinical studies, select qualified ones, extract and analyze data from them, and provide scientific basis for the diagnosis and treatment of diseases. Meta analysis refers to the use of statistical methods.
Systematic review and meta-analysis are the same or cross-used. If they are completely different, it can be called meta-analysis when the systematic review uses quantitative comprehensive method to statistically process meta-analysis. What does not use statistical methods is a qualitative systematic review.
Function:
Meta-analysis, especially the meta-analysis of comprehensive high-quality randomized controlled trials (RCT), is regarded as high-level evidence of evidence-based medicine and has the following functions:
(1) realize quantitative synthesis.
② Provide a systematic and repeatable comprehensive method for the same problem.
③ Integrating the research results of several small samples on the same topic can improve the statistical efficiency of the original results.
④ Solve the inconsistency of the research results and improve the estimated value of the effect.
⑤ Answer the questions not raised in the original study.
⑥ Explore the publication bias of existing literature.
⑦ Put forward new research questions and point out the direction for further research.