300 Cost to Correct International Normalized Ratio Among Patients With Warfarin-Associated Major Bleeding in Clinical Practice

Abstract

To assess differences in total inpatient costs among patients whose international normalized ratio (INR) remained uncorrected versus corrected following use of fresh frozen plasma in the management of warfarin-associated major bleeding. A retrospective database analysis was undertaken using electronic medical record data from a large integrated health system. Patients who received fresh frozen plasma between 01/01/2004 and 12/31/2010, and who met the following criteria were selected: major hemorrhage diagnosis the day before to the day after initial fresh frozen plasma administration; INR ≥ 2 on the day before or the day of fresh frozen plasma and another INR result up to 1 day after fresh frozen plasma; and supply of warfarin within 90 days prior to hospitalization. INR correction (defined as INR ≤ 1.3) was evaluated at the last available test up to 1 day following fresh frozen plasma start. Costs were evaluated for each patient's inpatient stay, including those for procedures, medications, physician visits, and facility usage. Statistical differences in costs between patients whose INR remained uncorrected versus corrected were evaluated with the Wilcoxon Rank-Sum test with statistical significance defined as P<0.05. All costs were adjusted to 2009 USD using the medical care component of the consumer price index. 414 patients met selection criteria (mean age 75 years, 53% male, mean baseline Charlson score of 2.5). The majority of patients presented with a gastrointestinal bleed (58%), followed by intracranial hemorrhage (38%) and other bleed types (4%). Thirty-three percent of patients were corrected at the last available test up to 1 day following receipt of fresh frozen plasma. Mean volume of fresh frozen plasma, packed red blood cells, platelets, vitamin K, and albumin received were not significantly different among patients whose INR was corrected versus uncorrected. Total inpatient costs (mean+SD) were not significantly different among patients whose INR was corrected at 24 hours following receipt of fresh frozen plasma versus patients who remained uncorrected ($18,941 ± $20,806 vs. $21,521 ± $20,767; P=0.09). Similarly, total costs were not significantly different by INR correction when stratified by quartiles of hospital length of stay or presenting bleed type. Using an alternative definition of INR correction at ≤ 1.5, total costs were also not significantly different (P=0.10). Timely and improved correction of INR values to a target of 1.3 or 1.5 among patients receiving fresh frozen plasma for warfarin-related major bleeding does not appear to be associated with greater total inpatient costs.