Oral Direct Factor Xa Inhibitors Versus Low-Molecular-Weight Heparin to Prevent Venous Thromboembolism in Patients Undergoing Total Hip or Knee Replacement: A Systematic Review and Meta-analysis. - Neumann I; Rada G; Claro JC; Carrasco-Labra A; Thorlund K; Akl EA; Bates SM; Guyatt GH (Annals of Internal Medicine, 2012)