Factors affecting in-hospital mortality among warfarin patients after implementing the warfarin management guideline of Lampang Hospital

Abstract

Background: Previous studies found that patients with a warfarin overdose had five times the risk of in-hospital mortality. Lampang Hospital has established guidelines for the care of patients receiving warfarin and the patients are closely monitored by pharmacists intensively. The guidelines were last updated in the fiscal year 2015 and are still in use today.
Objective: To study the factors affecting in-hospital mortality among warfarin patients after providing intensive monitoring.
Methods: A retrospective cross-sectional analytical study was done. Electronic medical records of patients who were prescribed warfarin during the fiscal year 2017 were reviewed retrospectively. An INR greater than four was used to identify warfarin overdose and the Charlson Comorbidity Index (CCI) was used to identify the clinical severity. Patient characteristic data was analysed using descriptive statistics. Factors associated with in-hospital mortality were analysed using a multivariable logistic regression model and was statistically significant at p<0.05.
Results: A total of 1,140 warfarin-treated patients were enrolled; 13.2% of warfarin overdose was reported. Most of them were on the Universal Health-care Coverage Scheme (74.3%) and were admitted in internal medicine wards (61.3%). Almost all of patients had the CCI less than or equal to 2 (91.7%). The length of hospital stay was 1 to 77 days with a median of 5 (3, 8) days, and were discharged when symptoms improved (89.9%). The in-hospital mortality was 4.8%. The factor significantly associated with in-hospital mortality was CCI (adjusted OR 1.2, p=0.041).
Conclusion: The risk factor for in-hospital mortality among patients taking warfarin was the severity of the patient's disease.