[Review Articles].

This paper summarizes the main features of review articles in medical topics. Articles can be classified as narrative reviews, systematic reviews or meta-analysis. Narrative reviews are appropriate to update etiology, pathophysiology or clinical aspects of diseases, and advances in basic and preclinical sciences. In systematic reviews the authors define its purpose, limit its scope, describe the literature search, define the inclusion and exclusion criteria adopted to select primary studies, and the criteria applied to assess the quality of their results and conclusions. Meta-analysis are quantitative, statistically analysed systematic reviews that consider mainly primary studies conducted prospectively with simultaneous randomized controls, pooling the data obtained from each of these primary studies in order to get a single estimate of effect. Systematic analysis and meta-analysis are important to evaluate new diagnostic and therapeutic tools, and they are most relevant to evidence-based medicine, mainly for the design of clinical guidelines and the adoption of new health care policies. Review articles published in Revista Médica de Chile were compared in one or two-year periods separated by ten years in between: in the "2001 period" 26 reviews were all narrative; in the "2010 period" 30 reviews were narrative and another 4 were systematic reviews; in the "2019 period" 14 reviews were narrative and another 7 were systematic reviews. No meta-analysis had been published in these periods, in this journal. Meta-analysis including primary studies performed in Chile by Chilean investigators have been published in English language in other medical journals. The educational and professional role of review articles is recognised, with a word of caution on a strict adherence to ethical rules adopted by scientific and clinical publications, mainly with respect to authorship and potential conflicts of interest.