Comparison of long versus short duration of anticoagulant therapy after a first episode of venous thromboembolism: a meta‐analysis of randomized, controlled trials

Abstract. Pinede L, Duhaut P, Cucherat M, Ninet J, Pasquier J, Boissel JP (Hôpital Edouard Herriot and Unité de Pharmacologie Clinique, Lyon, France). J Intern Med 2000; 247: 553–562.Objective. To assess the length of oral anticoagulant therapy (short versus long duration) after a first episode of venous thromboembolism (VTE).Design. Meta‐analysis of randomized controlled trials, comparing two durations of anticoagulation, identified in 1999 by a computerized search of the Cochrane Controlled Trial Register, Medline and Embase, completed by an extensive review of the references of pertinent articles.Setting and subjects. The meta‐analysis was performed on literature data. Seven published controlled trials were included. Relative risks with 95% confidence intervals were computed using the relative risk logarithm method. Statistical significance was set up at 0.01 for the test of association.Main outcome measures. Outcomes are major haemorrhage and recurrence after a 12‐month follow‐up.Results. For the recurrence end‐point (sample size of 2304 patients), a duration treatment of 12–24 weeks seems preferable to a 3–6 week regimen, with a relative risk (RR) of 0.60 (95% CI: 0.45–0.79, P