An Evaluation of Pharmacist Counseling to Patients Receiving Warfarin at Samutprakarn Hospital

Abstract

Objective: To assess outcomes of pharmacist’s counseling on outpatientsreceiving warfarin therapy at Samutprakarn hospital. Method: This beforeafteraction research study design compared patients’ knowledge,International Normalized Ratio (INR), bleeding events, thromboembolicevents, number of hospitalization (including emergency room visits), as wellas cost saving from hospitalization which could be avoided. Method: Thestudy participants were out-patients receiving warfarin since January, 2007,and had been followed up at warfarin clinic for at least 6 months. Patients’knowledge on warfarin was tested before and after establishing the clinic.Results: Based on 132 patients, their mean age was 57 years, and themajority was female (62.1%), with 50.8% having warfarin for atrialfibrillation, and 67.4% having an INR out of therapeutic range. Knowledgescore on warfarin was increased significantly after counseling (from 2.52 to8.84, P < 0.001). After the 3rd visit, such score was slightly decreased to8.13 but significant (P < 0.001). Frequencies of INR within therapeuticrange post-counseling (77.5%) were significantly higher than pre-counseling(22.1%), P < 0.001. Other significant improvements included bleeding(3.6% to 1.7%, P = 0.027) and number of hospitalization (1.8% to 0.5%, P= 0.029). Thromboembolic events were also decreased but not significant(2.2% to 1.6%). Cost saving of hospitalization was 242,357 baht/year.Conclusion: Patient counseling on warfarin by pharmacist improvespatients’ knowledge, clinical outcomes, and cost saving.Keywords: warfarin, warfarin clinic, program evaluation, pharmacistcounseling, clinical outcomes, cost saving