The Development of Drug Related Problems Record Forms and Pharmacist’s Dosage Recommendations at Warfarin Clinic, Saimoon Hospital, Yasothon Province

Abstract

Background: The Warfarin Clinic at Sai Mun Hospital was established in 2016. However, treatment outcomes remained suboptimal. In 2024, only 40.41% of patients achieved an INR in the target range. A review identified the primary problems as inadequate screening for drug-related problems (DRPs) and a warfarin dose adjustment approach inconsistent with standard guidelines.

Objective: To develop and evaluate the effectiveness of a Drug-Related Problem Record and Warfarin Dose Adjustment Guideline on the quality of patient care. Outcomes were measured in terms of INR target percentage, Time in Therapeutic Range (TTR), physician acceptance of pharmacist recommendations, pre- and post-intervention knowledge of warfarin among personnel, and satisfaction with the new record form.

Methods: This was a Prospective Quasi-experimental Study conducted at the Warfarin Clinic from April 1 to August 31, 2025. The study population consisted of personnel using the new record form and 60 outpatients receiving warfarin. The intervention utilized the self-developed Drug-Related Problem Record and Dose Adjustment Guideline. Data were collected using the Warfarin Registry Network (WaRN) program, comparing results before and after the intervention. Data analysis involved descriptive statistics, Paired t-test, and One-Way ANOVA, with statistical significance set at a p-value < 0.05.

Results: The overall percentage of patients with an INR in target significantly increased from 47.09% to 58.03% (p < 0.05). Specifically, the INR target value in both the normalized group and the poor control group increased significantly (p < 0.05). Percentage of TTR slightly decreased by 2.1% after the intervention. Physicians accepted pharmacist dose adjustment recommendations through the record form at a rate of 89.58%. Warfarin knowledge scores among personnel significantly increased, and personnel satisfaction with the record form was at the "Highest" level. No patients experienced major bleeding events.

Conclusion: The Drug-Related Problem Record and Warfarin Dose Adjustment Guideline improved the efficiency of patient care in the Warfarin Clinic by significantly increasing the INR in the target range. Increase knowledge and understanding of warfarin among multidisciplinary staff and promote systematic communication among personnel.