Quality of oral anticoagulant therapy in patients who perform self management: warfarin versus phenprocoumon

Background The quality of oral anticoagulant therapy may be related to which type of coumarin is used. The aim was to investigate whether phenprocoumon or warfarin provide the highest quality of oral anticoagulant therapy in patients who manage the therapy themselves. Methods and results In a cohort study 519 patients on self managed oral anticoagulant therapy were included. Quality control parameters, were, the percentage of time spent in the therapeutic range and the variability in the patients’ INR values. Time within therapeutic INR target range in the patient group treated respectively with warfarin and phenprocoumon was 70.2% and 74.0% (P = 0.008).The median variance in the warfarin group was 0.35 (95% CI (0.32–0.38)) and 0.29 (95% CI (0.25–0.33)) in the phenprocoumon group (P = 0.0004). Conclusion Phenprocoumon provides a higher percentage of time spent in therapeutic INR interval and a lower variation of INR-values compared with warfarin.