Edelstein AI, et al. - This trial was conducted to assess whether, following warfarin initiation in total joint arthroplasty patients, a rapid increase in the international normalized ratio was a risk factor for venous thromboembolism. Experts noted a rapid rise in this ratio to be associated with an increased risk of symptomatic venous thromboembolism. The results identified a population at risk of the symptomatic venous thromboembolism.