Background: Approximately 40-45% interpatient variability in response to warfarin is still conspicuous. These uncertainties contribute to warfarin’s underuse in patients who could benefit from anticoagulation. Anticoagulation clinics provide systematic method for anticoagulation management, warfarin dosage adjustment and patient education.
Methods: Prospective case-control study was conducted from May to September 2012 at surgical outpatient department at Shahid Gangalal National Heart Center, Nepal to compare physician-pharmacist collaborative anticoagulation clinic (PPAC) approach on warfarin therapy management (case) to usual anticoagulation therapy (UAT) provided by physicians (control). Control (n=75) and case group (n=75) were selected by systematic random sampling in such a way that ratio of control to case is 1:1. Participants who required warfarin for their mechanical heart valve replacement for at least three months via UAT approach were included. They were counseled on dosage regimen, diet, signs and symptoms of hemorrhagic or thromboembolic events. Patient anticoagulation therapy leaflet was provided to case group. Data related to warfarin were analyzed using repeated measure ANOVA. A p<0.05 was considered statistically significant.
Results: Baseline international normalized ratio (INR) value in UAT approach (4.45 ± 2.00) was changed to 4.21 ± 1.75, 4.45 ± 2.00 and 4.21 ± 1.75 with p 0.807, 0.000 and 0.807 during first, second and third follow ups. In PPAC, baseline INR value (0.99 ± 0.81) was constantly maintained to 2.21 ± 0.77 with p 0.000 throughout all follow ups. In PPAC, baseline monthly cost minimizations were statistically significant, with p 0.000 on each.
Conclusion: INR value of patient in PPAC approach was statistically within recommended range (p 0.000 on each condition). The study showed that INR value of the patients can be kept within the recommended range when physicians and pharmacist collaboratively manage patients’ warfarin therapy.