Definition of systematic review of evidence-based medicine: aiming at a specific clinical problem (etiology, prognosis, diagnosis and intervention effect), systematically and comprehensively collect all the published or unpublished international related clinical research articles, screen out qualified studies with unified and scientific evaluation criteria, conduct quality evaluation, make quantitative synthesis with statistical methods or qualitative synthesis with descriptive methods, draw reliable conclusions, and update them in time with the emergence of new clinical research results. As a research, systematic review is published in the form of a paper.