Objective: To provide current and emerging evidence on oral contraceptives and the risk of venous thromboembolism.
Evidence: Articles published in English from 2005 were retrieved through searches of PubMed and Medline, using the following terms: venous thromboembolism, VTE, contraception, oral contraceptives, hormonal contraception. Results were restricted to systematic reviews, randomized control trials/controlled clinical trials, and observational studies. Searches were updated on a regular basis and incorporated in the guideline to May 2010. Grey (unpublished) literature was identified through searching the websites of health technology assessment and health technology assessment-related agencies, clinical practice guideline collections, clinical trial registries, and national and international medical specialty societies.
Values: The quality of evidence was rated using the criteria described by the Canadian Task Force on Preventive Health Care (Table).