Home prophylactic warfarin anticoagulation program after hip and knee arthroplasty.

OBJECTIVE: To determine the efficiency of a program designed to maintain prophylactic oral anticoagulation within a target range for 6 weeks after hip and knee arthroplasty. DESIGN: A prospective continuous quality improvement indicator. SETTING: A tertiary care university hospital. PATIENTS: Patients who underwent hip and knee arthroplasty and had no indications for routine anticoagulation other than postoperative thromboembolism prophylaxis. INTERVENTION: An outpatient warfarin prophylaxis program, which included an information letter given to the patient. Home Care coordinated community laboratory services, communication with and anticoagulant dosage adjustment by the patient's personal family physician. OUTCOME MEASURES: The proportion of international normalized ratio (INR) values within, below and above the target range of 2.0 to 3.0. RESULTS: Sixty-two patients were enrolled over a 3-month period. On the day of hospital discharge, 64% of patients had INR values that were within the target range, 31% were below and 5% were above. After hospital discharge, 42% of the INR values were within the target range, 48% were below and 10% were above. CONCLUSION: Despite a program designed to address patient information, physician communication and laboratory testing, tight control of home INR values could not be achieved with the existing resources of Home Care and family physicians.