Applying a Computer-based Warfarin Management System at a Large Tertiary Cardiovascular Center in Iran

Abstract

Background: Regarding adjustments to warfarin dosage, numerous studies have shown that computerized methods are superior to those based on personal experience. Objectives: To report the efficacy of a computer-based warfarin management system (WMS) in the Iranian population. Methods: By utilizing the existing dosing algorithms and obtaining expert opinions, we developed a computer-based WMS at a large tertiary cardiovascular center. The time in therapeutic range and the number of international normalized ratio (INR) tests of clinic patients were compared before and after the implementation of WMS. Results: Overall, 803 patients with 5407 INR tests were included in the before phase and 679 patients with 4189 INR tests in the after phase. The mean time in therapeutic range was 57.3% before and 59% after WMS implementation [mean difference, 1.64; 95% confidence interval (CI), −1.12–4.40]. In the before phase, the mean number of INR tests was 6.7, which dropped to 6.1 tests in the after phase (mean difference, −0.61; 95% CI, −0.97 to −0.24). Only 54.5% of the warfarin dosing prescriptions were consistent with the dosing recommendations of the WMS, and adherence to the WMS was poorest in the highest INR target range. Conclusions: For the first time in Iran, we demonstrated that a computerized system was as effective as a traditional experience-based method to monitor INR in VKA-anticoagulated patients. Furthermore, it could reduce both the number of INR tests and that of visits.