Pharmacist-led medicine use review in community pharmacy for patients on warfarin

Background Medicine use review by pharmacists has the potential to improve anticoagulation therapy management in patients on warfarin. Objective To develop, implement and evaluate a pharmacist-led medication use review service for patients on warfarin. Setting Six community pharmacies in Malta. Method Patients (N = 100) aged 18 or older and on warfarin were recruited through pre-selected community-pharmacies. These patients were then invited to attend two sessions: a review session (t₁) and a follow-up session after 2 months (t₂). During the medication use review session, medication reconciliation was performed (a) to detect drug-related problems using the DOCUMENT classification system, (b) to develop an individualised care plan for each patient and (c) to recommend an action for each identified problem for physician, pharmacist or patient consideration. At t₂, the degree of acceptance of the recommendations was determined by assessing the number of drug-related problems for which action was taken to address the problem. International normalisation ration (INR) control was evaluated by calculating the percentage Time in Therapeutic Range (TTR) at t₁ and t₂ using the Rosendaal linear interpolation method. Main outcome measures Frequency and type of drug-related problems detected; percentage of accepted recommendations; and INR control. Results A total of 481 drug-related problems were identified; 40% (n = 190) were related to warfarin treatment. Need for monitoring (30%; n = 145), lack of compliance (20%; n = 97) and need for patient education (19%; n = 90) were the top three problems identified. There was a significant correlation between frequency of the problems and number of chronic medications (Spearman Correlation 0.583, p < 0.001), number of comorbidities (Spearman Correlation 0.327, p = 0.001) and older age (Spearman Correlation 0.285, p = 0.04). A total of 475 recommendations were followed-up; 49% (n = 234) were referred for consideration by the physician. The percentage of recommendations accepted (84%; n = 397) was significantly higher than the percentage of recommendations not accepted (16%; n = 78) (p < 0.001). The time in therapeutic range improved significantly from 68.7% at t₁ to 79.8% at t₂ (p = 0.01). Conclusions The high percentage of accepted recommendations and the improvement in INR control indicate that a pharmacist-led medication use review service in community pharmacy contributes to improving anticoagulation therapy management in patients on warfarin.