Management of chronic venous disorders of the lower limbs: guidelines according to scientific evidence.

Disclaimer Due to the evolving field of medicine, new research may, in due course, modify the recommendations presented in this document. At the time of publication, every attempt has been made to ensure that the information provided is up to date and accurate. It is the responsibility of the treating physician to determine the best treatment for the patient. The authors, committee members, editors, and publishers cannot be held responsible for any legal issues that may arise from the citation of this statement. Rules of evidence Management of patients with chronic venous disorders has been traditionally undertaken subjectively among physicians, often resulting in less than optimal strategies. In this document, a systematic approach has been developed with recommendations based upon cumulative evidence from the literature. Levels of evidence and grades of recommendation range from Level I and Grade A to Level III and Grade C. Level I evidence and Grade A recommendations derive from scientifically sound randomized clinical trials in which the results are clear-cut. Level II evidence and Grade B recommendations derive from clinical studies in which the results among trials often point to inconsistencies. Level III evidence and Grade C recommendations result from poorly designed trials or from small case series.1, 2 Meta-analysis Meta-analyses are included in the present document but there should be caution as to their possible abuse. Certain studies may be included in a meta-analysis carelessly without sufficiently understanding of substantive issues, ignoring relevant variables, using heterogenous findings or interpreting results with a bias.3 It has been demonstrated that the outcomes of 12 large randomized controlled trials were not predicted accurately 35% of the time by the meta-analyses published previously on the same topics.4