Initiation of warfarin therapy - Comparison of physician dosing with computer-assisted dosing

In a prospective, randomized study at two university hospitals, the authors examined how effectively housestaff physicians (n=36) managed the initiation of warfarin therapy compared with a computer-assisted dosing regimen (n=39) using the software program Warfcalc, which was managed by one of the authors. Target prothrombin time ratios were selected by the physicians. Study endpoints included: the time to reach a therapeutic prothrombin ratio, the time to reach a stable therapeutic dose, the number of patients transiently overanticoagulated, the number of bleeding complications, and the accuracy of the predicted maintenance dose, which was assessed at steady-state 10–14 days later. Computer-assisted dosing consistently outperformed the physicians: a stable therapeutic dose was achieved 3.7 days earlier (p=0.002), fewer patients were overanticoagulated (10% versus 41%), and the predicted maintenance dose was in the therapeutic range in 85% of the computer-dosed patients versus 42% of the physician group (p<0.002). For physicians who did not routinely manage warfarin therapy, computer-assisted dosing improved the accuracy of dosing and shortened the time required to achieve a stable therapeutic dose.