경구용 항응고제 치료적적성 분석법 비교

Abstract

Background: Various methods have been described to evaluate efficacy of anticoagulant therapy using the international normalized ratio(INR) of prothrombin time. We compared the following approaches: (1) cumulative INR which considers the number of INR measurements within the target range of the total number of values obtained; (2) cross-section-of-the-files that considers only the most recent INR; (3) percent time within therapeutic range, with INR changing directly or halfway between visits. Methods: For the assessment of therapeutic quality control in Yonsei Cardiovascular Center, 848 patients with warfarin therapy for cardiovascular diseases in the period from December 1 to December 31, 1996 were assessed by cross-section-of-the-files method. The target anticoagulant ranges were 2.0~3.0 INR for most diseases and 2.5~3.5 for the mechanical valve replacement. We also analysed three assessment methods using INR results from 52 patients who had been treated for one year or longer. Results: With the results by cross-section-of-the-files, the patients(n=848) during the year 1996 were found to be anticoagulanted in 41.5%, within the therapeutic range in 37.0% and over-anticoagulated in 21.5%. Using three assessment methods(n=52), 34.8%, 30.8% and 34.7% of INRs obtained were within the therapeutic range by cumulative INR, cross-section-of-the-files and percent time approaches, respectively. Conclusions: Our results by cross-section-of-the-files method have shown that many patients with oral anticoagulation were not in optimal therapeutic ranges. The comparative results of the three different methods were not significantly different for the assessment of oral anticoagulation. We concluded that cross-section-of-the-files method can be easily applied in clinical situations.