[Critical appraise of systematic reviews in vascular surgery. A practical example]

Basic and clinical research are the basis for the advances in medicine. Nowadays we investigate everything (patients, diseases, health systems, outcomes, management, policies, etc.) and this research is reflected in a growing number of published medical articles, with millions of papers stored in the biomedical databases. There is the need to select, analyze and synthesize all this evidence, and making it available in a simple and timely fashion to the decision makers. One instrument to achieve this is the guidelines, another is the systematic reviews of the literature. Systematic reviews are research projects per si and constitute a very significant scientific advance, with clear implications in clinical care, scientific research and even policies, because they are integrative analytic instruments of the available information, allowing evidence-based answers. Recently a Cochrane Library systematic review was published showing benefits of escin in chronic venous insufficiency. We appraise this study in terms of validity, importance and applicability as an example of critical appraisal of the scientific evidence.