Anticoagulation Control of Warfarin in Pharmacist-Led Clinics Versus Physician-Led Clinics: A Prospective Observational Study

Purpose: Warfarin is an affordable drug used for numerous indications, and still a favorable choice for patients with a history of bleeding from direct oral anticoagulants or presence of valvular heart diseases. However, warfarin requires regular international normalized ratio (INR) monitoring for safety and efficacy. Warfarin's efficacy and safety is correlated with actual time spent within the therapeutic INR. Time in therapeutic range (TTR) is an estimate that measures the percentage of actual time spent within the therapeutic INR. Our aim was to investigate differences in anticoagulation control of warfarin using TTR between pharmacists and other health-care providers. Methods: This prospective observational study was conducted in an ambulatory-care setting of a tertiary hospital to compare anticoagulation management using TTR between clinics run by pharmacists versus other health-care providers. Results: A total of 62 patients were enrolled: 33 in the pharmacist-led clinic and 29 in the physician-led clinic. TTR levels were statistically higher among patients in the pharmacist-led clinic than than the physician-led clinic (87.27%+/- 3.82% and 52.48%+/- 5.49%, respectively; p<0.001). For 27 patients followed retrospectively by physicians and prospectively by clinical pharmacists, TTR was statistically higher during clinical pharmacists' care (91.70% +/- 2.93% versus 61.39%+/- 5.11%, respectively; p<0.001). During the study, approximately 82% of patients reached their target INR in the pharmacist-led clinic compared to 24% in the physician-led clinic. Conclusion: The findings of our study found that patients followed in the pharmacist-led clinic had higher TTR levels than those followed in the physician-led clinic.