4 years’ experience with a pharmacy warfarin dosing service for orthopedic rehabilitation inpatients

Abstract

Rationale Complex, surgical patients are routinely referred to rehabilitation hospitals for subacute and transition care. Before 2003, there was no anticoagulation service at Providence Healthcare (PH). Objectives The goals of the pharmacy warfarin service were: (1) to optimize anticoagulation management; and (2) to improve patient outcomes. Design The key ingredients were a strong interdisciplinary team; certified anticoagulation pharmacists; an evidence-based medicine approach to anticoagulation management; and continuous quality improvement. Retrospective evaluations were completed 2003–2006, comparing two control groups to the anticoagulation service patients. Results The 2003/2004 (5month) pilot project started on an orthopedic rehabilitation unit. The control groups showed less favourable patient outcomes. Without warfarin nomograms, protocols or anticoagulation training, there was delayed time to therapeutic INR (3.03 days); less therapeutic INR results (50.9%); more subtherapeutic INRs (33.2%) and supratherapeutic INRs (14.9%); increased morbidity and mortality (e.g. 1 fatal PE, 2 major bleeds, 5 doses of vitamin K). The results showed that the warfarin dosing service was safer and more effective. Advantages included faster time to therapeutic INR (2.84 days); more INR results (67.9%) within the therapeutic range; less subtherapeutic INR results (22.7%) and supratherapeutic INR (9.4%); no vitamin K or FFP; no new diagnoses of DVT, PE or CVA; and no deaths. Two more 12-month evaluations were completed, also showing favourable results (for 2004/2005 and 2006). Upon demand, the anticoagulation service expanded into stroke and transitional rehabilitation units in 2006. Conclusion This cost-effective anticoagulation service is supported by a strong interdisciplinary team and 4 years of data analysis.