This issue of the Scottish Medical Journal has a few systematic reviews and critical analysis of literature in many areas. We feel that for clinical practice, evidence is essential and systematic reviews summarize evidence for us through a scientific synthesis. The range of topics of systematic reviews. [1][2][3][4][5][6][7][8] in this issue has been wide and not focusing on a particular problem, however, publications should generate awareness, some glimpse into methodology and associated discussions around evidence-based medicine.Evidence-based medicine is a combination of individual clinical knowledge and the results of clinical trials. And as a doctor, there is a great need for some strong evidence to support his diagnosis and treatment and all aspects of it. 9 Due to the proliferation of medical literature and the limited time available to clinicians and researchers, systematic evaluation was born. The systematic evaluation aims to obtain stronger clinical evidence for clinical decisionmaking by systematically searching medical databases. So high-quality systematic reviews are needed. 9 The quality of a systematic review depends on the number and quality of the studies included and the presence of heterogeneity. Choosing a good topic is the beginning of preparing a systematic review. Once you have chosen a topic, you can start with the Protocol. At this stage, most journals recommend that we use The Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) to assist in the writing of our articles. 10 PROSPERO (http://www.crd.york.ac.uk/prospero/) is a well-known platform for registration of system overviews, so it is best to make a registration on such a platform. 11 And check if anyone has done any relevant research to avoid duplication. 12 In particular, for clinical questions, authors should use the "Participants, Interventions, Comparisons and Outcomes (PICO)" to analyze the question before starting the process of conducting a systematic review. 13 The search strategy is mainly to link some keywords by means of 'and' and 'or' to achieve a search of the relevant literature. Then it is a matter of selecting the appropriate database for the search, e.g. PubMed, Web of Science, Embase, Cochrane Library, CENTRAL, Cinahl, and LiLacs., etc. Searches can be conducted within them using keywords and appropriate filters such as time