Abstract

Warfarin therapy is effective for the treatment of thromboembolic diseases, yet is underused and poorly managed because delivery of treatment is complex. A pharmacist-managed anticoagulation clinic resulted in improved warfarin management, fewer adverse outcomes related to poor anticoagulation control, and cost savings. These results support decisions in Ontario to expand the scope of pharmacist practice. Background: Warfarin therapy is effective for the treatment of thromboembolic diseases, yet is underused and poorly managed because delivery of treatment is complex. Inadequate anticoagulation can result in thromboembolic events such as stroke and excessive anticoagulation increases risk of bleeding. Anticoagulant management services (AMS) can improve access to and management of warfarin therapy. This study assessed the efficacy of a unique pilot AMS in Alberta where all direct care is provided by pharmacists with an extended scope of practice and work in consultation with specialist physicians.

Methods: Patients were eligible for inclusion if they were prescribed warfarin for at least four months before referral and to have continued treatment for four months or more at the AMS. After referral to the AMS, patients received a standard individual educational session and an information package where they were informed of the importance of compliance to therapy, risks and benefits of warfarin therapy, factors that can affect effectiveness of therapy, and signs and symptoms of complications. Adequacy of anticoagulation was assessed by measuring the proportion of time patients spent in their target international normalized ratio (INR) range. Other outcomes of interest included rates of complication and associated health care utilization; both were measured using hospital utilization data coded according to the International Classification of Diseases (ICD-9 and ICD-10) specifications. All outcomes were evaluated before and during AMS care.

Findings: 125 patients were eligible to this study. The proportion of time that patients were in their indicated INR rate before referral was found to be 48.8%, while during AMS care this proportion increased to 66.5%. . Before AMS care, significantly more patients were admitted to the emergency department and were hospitalized due to thromboembolic events than during AMS care (49 events/100 patient years compared to 3.6 events/100 patient years). The associated cost of hospital stays was substantially lower during AMS care ($12,765.20 versus $134,910.60).

Conclusions: AMS care was significantly associated with improvements in warfarin management and fewer adverse outcomes related to poor anticoagulation control. AMS care also resulted in monthly savings of 53 emergency department hours and $11,415.46 in hospital costs. These results highlight that a pharmacist-managed anticoagulation clinic is safe and effective, and supports Ontario policy-makers' proposal to expand pharmacists' role in reviewing and monitoring medication , which may be a good way to address rising physician shortages in Canada and provide better care outcomes for o patients.

References

Bungard TJ, Gardner L, Archer SL, Hamilton P, Ritchie B, Tymchak W, et al. Evaluation of a pharmacist-managed anticoagulation clinic: Improving patient care. Open Medicine, 2009; 3(1): 16-21