Open Access Highly Accessed Research article

Comparison of pharmacist managed anticoagulation with usual medical care in a family medicine clinic

Stephanie Young1*, Lisa Bishop12, Laurie Twells12, Carla Dillon12, John Hawboldt12 and Patrick O'Shea23

Author affiliations

1 School of Pharmacy, Memorial University, 300 Prince Philip Drive, St. John's, A1B 3V6, Canada

2 Faculty of Medicine, Memorial University, 300 Prince Philip Drive, St. John's, A1B 3V6, Canada

3 Newfoundland Drive Family Practice, 427 Newfoundland Drive, St. John's, A1A 4A5, Canada

For all author emails, please log on.

Citation and License

BMC Family Practice 2011, 12:88  doi:10.1186/1471-2296-12-88

Published: 17 August 2011



The beneficial outcomes of oral anticoagulation therapy are dependent upon achieving and maintaining an optimal INR therapeutic range. There is growing evidence that better outcomes are achieved when anticoagulation is managed by a pharmacist with expertise in anticoagulation management rather than usual care by family physicians. This study compared a pharmacist managed anticoagulation program (PC) to usual physician care (UC) in a family medicine clinic.


A retrospective cohort study was carried out in a family medicine clinic which included a clinical pharmacist. In 2006, the pharmacist assumed anticoagulation management. For a 17-month period, the PC group (n = 112) of patients on warfarin were compared to the UC patients (n = 81) for a similar period prior to 2006. The primary outcome was the percentage of time patients' INR was in the therapeutic range (TTR). Secondary outcomes were the percentage of time in therapeutic range within ± 0.3 units of the recommended range (expanded TTR) and percentage of time the INR was >5.0 or <1.5.


The baseline characteristics were similar between the groups. Fifty-five percent of the PC group was male with a mean age of 67 years; 51% of the UC group was male with a mean age of 71 years. The most common indications for warfarin in both groups were atrial fibrillation, mechanical heart valves and deep vein thrombosis. The TTR was 73% for PC and 65% for UC (p < 0.0001). The expanded TTR for PC was 91% and 85% for UC (p < 0.0001). The percentage of time INR values were <1.5 was 0.7% for PC patients and 1.9% for UC patients (p < 0.0001), and >5 were 0.3% for PC patients and 0.1% for UC (p < 0.0001).


The pharmacist-managed anticoagulation program within a family practice clinic compared to usual care by the physicians achieved significantly better INR control as measured by the percentage of time patients' INR values were kept in both the therapeutic and expanded range. Based on the results of this study, a collaborative family practice clinic using pharmacists and physicians may be an effective model for anticoagulation management with these results verified in future prospective randomized studies.