Risk factors associated with warfarin overdose and complications related to warfarin overdose in the emergency department

The aim of this study was to investigate risk factors of bleeding and mortality in patients with warfarin overdose (WOD). Totally, 783 patients were included, of which, 272 patients (34.7%) with an INR below 5,364 patients (46.5%) with an INR between 5–10, and 147 patients (18.8%) with an INR of 10 or above. Demographic, clinical, and laboratory findings of the patients were obtained from the Real Life Data Provision Center and Hospital Information Management System. Admittance in autumn (OR = 1.75; p = 0.012), INR = 5–10 (OR = 2.65; p < 0.001), INR ≥ 10 (OR = 9.06; p < 0.001), and antiplatelet use alongside warfarin (OR = 1.93; p < 0.001) were found to be independent risk factors for bleeding in this study. The age (OR= 1.03; p = 0.005), bleeding (OR = 1.69; p = 0.020), primary hypertension (OR = 1.72; p = 0.031), and INR ≥ 10 (OR = 2.02; p = 0.025) were found to be independent risk factors for mortality. The cutoff value for INR in predicting bleeding was found to be >6.35 with 74.2% sensitivity and 72.7% specificity. The significant risk factors were determined in WOD development. INR level, autumn, and antiplatelet use were independently associated with bleeding due to WOD. In addition, bleeding, hypertension and INR levels were independently related to in-hospital-mortality due to WOD.