Computerized management of oral anticoagulant therapy: experience in major joint arthroplasty.

Objective: Evaluation of the safety and potential cost savings of a computerized, laboratory-based program to manage inpatient warfarin thromboprophylaxis after major joint arthroplasty. Design: A consecutive-case study of adults. Setting: A tertiary care orthopedic institution. Patients: Patients requiring joint arthroplasty who had no recent episodes of thromboembolic disease, no mechanical heart valve, atrial fibrillation, severe liver disease or baseline international normalized ratio [INR] greater than 1.3 admitted over a 54-month period (July 1994‐December 1998). All patients received a standard regimen of warfarin beginning on the evening after the operation. Four hundred and thirty randomly selected patients managed by the program were followed up by telephone survey 3 months after discharge. Patients exhibiting erratic responses to warfarin were withdrawn from the program and managed individually thereafter. Intervention: Major joint arthroplasty with warfarin therapy administered through the computerized program. Main outcome measures: Test results maintained within the desired therapeutic range (INR 2.0‐3.0), clinically severe bleeding episodes, readmission rates, clinically symptomatic and venographically proven episodes of venous thrombosis or pulmonary embolism. Results: Over the study period 5629 patients underwent joint arthroplasty; 5372 patients were considered for the program; 332 patients were ineligible and were managed individually; 311 entered patients did not complete the program. This left 4729 patients who completed the program. In 2932 (62%) patients test results were maintained in the desired therapeutic range. The major bleeding rate was less than 0.5%, the readmission rate was 3.8%, the deep venous thrombosis rate was 3.7% and the pulmonary embolism rate was 0.2% with no thromboembolic related deaths in the small sample cohort. Conclusions: The majority of patients requiring warfarin thromboprophylaxis can be safely and effectively managed by this laboratory-based computerized program while in hospital. Significant potential cost savings in nursing time could be achieved. Objectif : Evaluer la surete et les reductions de couts rendues possibles par un programme informatise de laboratoire pour prendre en charge la thromboprophylaxie a la warfarine chez des patients hospitalises apres une arthroplastie d’une articulation majeure. Concept : Etude de cas consecutifs chez des adultes. Contexte : Etablissement orthopedique de soins tertiaires. Patients : Patients ayant besoin d’une arthroplastie d’une articulation et n’ayant pas d’episode recent de thrombo-embolie, pas de valvule cardiaque mecanique, de fibrillation auriculaire, de maladie grave du foie, ou ne presentant pas un ratio international normalise [RIN] de base de plus de 1,3, hospitalises au cours d’une periode de 54 mois (juillet 1994 a decembre 1998). Tous les patients ont recu un regime normalise de warfarine a compter du soir qui a suivi l’intervention. On a effectue un suivi telephonique, trois mois apres le conge, aupres de 430 patients choisis au hasard et pris en charge par le programme. Les patients qui reagissaient de facon erratique a la warfarine ont ete retires du programme et pris en charge individuellement par la suite. Intervention : Arthroplastie d’une articulation majeure et therapie a la warfarine administree au moyen du programme informatise. Principales mesures de resultats : Resultats d’analyse maintenus a l’interieur de la plage therapeutique visee (RIN, 2,0‐3,0), episodes de saignement grave sur