Effects of computer-assisted oral anticoagulant therapy

Abstract

Background: Computer-assistance and self-monitoring lower the cost and may improve the quality of anticoagulation therapy. The main purpose of this clinical investigation was to use computer-assisted oral anticoagulant therapy to improve the time to reach and the time spent within the therapeutic target range compared to traditional oral anticoagulant therapy by physicians.

Methods: 54 patients were randomized equally into 3 groups. Patients in two groups used CoaguChek® systems to measure international normalized ratio (INR) values and had dosages of anticoagulation treatment calculated in a computer system by an algorithm specific to each group. The third group received traditional anticoagulation treatment by physicians. The obtained INR values were compared regarding the time to reach, and the time spent within, the therapeutic target range, corresponding to INR values from 2 to 3.

Results: Patients randomized to computer-assisted anticoagulation and the CoaguChek® system reached the therapeutic target range after 8 days compared to 14 days by prescriptions from physicians (p = 0.04). Time spent in the therapeutic target range did not differ between groups. The median INR value measured throughout the study from all patients by CoaguChek® at 2.5 (2.42-2.62) was lower than measured by a hospital-based Clinical and Biochemical Laboratory at 2.6 (2.45-2.76), (p = 0.02).

Conclusions: The therapeutic target range was reached faster by the use of computer-assisted anticoagulation treatment than prescribed by physicians, and the total time spent within the therapeutic target range was similar. Thus computer-assisted oral anticoagulant therapy may reduce the cost of anticoagulation therapy without lowering the quality. INR values measured by CoaguChek® were reliable compared to measurements by a clinical and biochemical laboratory.

Figure 1

Patients assigned to computer-assisted oral anticoagulant therapy reached the TTR faster than patients assigned to traditional oral anticoagulant therapy performed by a physician. Median days until first INR measurements in the TTR are illustrated in combination with associated 25^th and 75^th percentiles in respective groups. Error bars define 5^th and 95^th percentiles. ^*P < 0.05.