Implementation and evaluation of a warfarin patient self-management (PSM) program among experienced patients in a U.S. academic health system.

Warfarin patient self-management (PSM) is when a patient independently manages their warfarin therapy using a decision-support tool provided by their anticoagulation provider. Clinical trials of PSM, conducted predominantly in Europe, have consistently demonstrated superior efficacy without compromising safety. However, the evidence-based practice of PSM is rarely utilized in the United States (U.S.). We describe initiatives completed to implement a successful PSM program among experienced warfarin-taking patients in a U.S. academic health system by overcoming perceived barriers. The results showed PSM resulted in similar or improved INR control, and an estimated 68% reduction in pharmacist workload.

A risk-stratified approach to venous thromboembolism prophylaxis with aspirin or warfarin following total hip and knee arthroplasty: A cohort study.

INTRODUCTION: Venous thromboembolism (VTE) and bleeding events following total knee and hip arthroplasty (TKA/THA) are associated with significant morbidity. Clinical guidelines recommend administration of pharmacologic VTE prophylaxis post-operatively, although controversy exists regarding optimal prophylactic strategies. METHODS: We performed a retrospective cohort study in patients who underwent elective TKA/TKA in an academic medical center. Patients were stratified by surgery type (TKA/THA) and VTE risk determined by a novel risk stratification protocol and compared pre- and post-protocol implementation. Patients received warfarin pre-protocol and either aspirin or warfarin post-protocol for VTE prophylaxis. Natural language processing identified VTE events and ICD codes were used to identify bleeding events, with all events validated manually. RESULTS: A total of 1379 surgeries were included for analysis, 839 TKAs and 540 THAs. Post-protocol implementation, 445 (94.1%) patients following TKA and 294 (97.4%) patients following THA received aspirin for VTE prophylaxis. A significant reduction in bleeding events (hazard ratio [HR] = 0.19, p = 0.048) was observed in low-risk THA patients treated with aspirin (post-protocol) compared patients treated with warfarin (pre-protocol). Bleeding events did not differ significantly between low-risk TKA patients treated with aspirin or warfarin. No significant differences in VTE events were observed following the protocol implementation. CONCLUSIONS: The use of a novel risk stratification system to guide VTE prophylaxis selection between aspirin or warfarin following TKA and THA appears safe and effective. Among low-risk patients, aspirin use was associated with fewer bleeding events following THA, without an observed increase in VTE events.

Patterns and Appropriateness of Thrombophilia Testing in an Academic Medical Center.

BACKGROUND: Clinical guidelines recommend against routine use of thrombophilia testing in patients with acute thromboembolism. Thrombophilia testing rarely changes acute management of a thrombotic event. OBJECTIVE: To determine appropriateness of thrombophilia testing in a teaching hospital. DESIGN: Retrospective cohort study. SETTING: One academic medical center in Utah. PARTICIPANTS: All patients who received thrombophilia testing between July 1, 2014, and December 31, 2014. MAIN MEASUREMENTS: Proportion of thrombophilia tests occurring in situations associated with minimal clinical utility, defined as tests meeting at least 1 of the following criteria: discharged before results available; test type not recommended; testing in situations associated with decreased accuracy; duplicate testing; and testing following a provoked thrombotic event. RESULTS: Overall, 163 patients received a total of 1451 thrombophilia tests for stroke (50% of tests; 35% of patients), venous thromboembolism (21% of tests; 21% of patients), and pregnancy-related conditions (15% of tests; 25% of patients). Of the 39 different test types performed, the most common were cardiolipin IgG and IgM antibodies (9% each), lupus anticoagulant (9%), and ß2-glycoprotein 1 IgG and IgM antibodies (8% each). In total, 911 tests (63%) were performed in situations associated with minimal clinical utility, with 126 patients (77%) receiving at least one such test. Only 2 patients (1%) had clear documentation of being offered genetic consultation. CONCLUSIONS: Thrombophilia testing in this single-center study was often associated with minimal clinical utility. Strategies to improve testing practices (eg, hematology specialty consult prior to inpatient testing, improved order panels) might help minimize inappropriate testing and promote value-driven care.

Comparison of two point-of-care international normalized ratio devices and laboratory method.

: A number of factors contribute to interlaboratory variation of international normalized ratio (INR) results. This variability can lead to differences in clinical decision-making. This prospective cohort study evaluated the accuracy, precision, and clinical decision-making variability of two point-of-care (POC) devices (CoaguChek XS and the Coag-Sense) to a clinical laboratory method of INR measurement as the 'reference' and by using the laboratory's accuracy standard (±25% of the reference INR). Study subjects included adults taking warfarin undergoing a POC INR with each device and a laboratory INR on the same day and evaluated differences in clinical decision-making using a warfarin nomogram. A correction factor was derived for each POC method to estimate the corresponding laboratory INR for POC INRs more than 3.0. A total of 100 patient encounters (76 unique patients) included INR testing by all three methods. Both POC devices demonstrated excellent precision across the entire range (r = 0.98), but poor accuracy relative to the laboratory standard for POC INRs greater than 3.0 (accuracy CoaguChek 19% and Coag-Sense 35%). A correction factor applied to POC INRs greater than 3.0 improved accuracy to 99% for both devices. Applying the correction factor also significantly reduced differences in clinical decision-making (49-28% for CoaguChek and 56-40% for Coag-Sense, P < 0.001). Both POC devices demonstrated poor accuracy for INRs over 3.0. A device-specific, institution-specific correction factor applied to POC INRs greater than 3.0 can provide better accuracy of INR measurement and can significantly reduce variability in warfarin dosing decisions. More study is needed to assess impact on clinical adverse events.