Improving Anticoagulation Therapy Using Point-of-Care Testing and a Standardized Protocol

Abstract

Many patients in primary care require anticoagulation with warfarin for the prevention of venous and systemic embolism. Achieving the goal international normalized ratio (INR) with warfarin is challenging. The purpose of this quality improvement initiative was to increase the proportion of patients taking warfarin with an INR value within the goal range. We included all patients identified on an anticoagulation log in the family medicine residency practice during 3 time periods: baseline, after point-of-care (POC) testing was initiated (intervention period 1), and after a standardized warfarin-dosing protocol was implemented (intervention period 2). Educational sessions were conducted during each intervention period. Measures included the frequency of INR monitoring and the percentage of office visits in which patients' values were within the goal INR range. Data were analyzed using descriptive statistics, the Student t test, and the chi2 test. At baseline, patients had an average of 2.6 INR tests performed, and 30.8% were within the INR goal range. Using POC testing, the frequency of monitoring increased to 4.3 INR tests per patient (P = .04), but the percentage of patients within the INR goal remained low at 32.1% (P=.88). When physicians implemented the standardized protocol to guide warfarin dosing, the frequency of testing was similar (3.8 tests per patient), but the percentage of patients within the INR goal increased to 45.9% (P<.04). POC testing increased the frequency of INR testing, and additional use of a standardized protocol for warfarin dosing increased the percentage of patients within the INR goal range. This model of anticoagulation management could be easily implemented in any family medicine office.