Comparing the effectiveness of pharmacist-managed warfarin anticoagulation with other models: a systematic review and meta-analysis

What is known and objectiveAnticoagulation management services are well known to improve the quality of patient care and to reduce the rates of hospitalization and emergency department visits following adverse events related to anticoagulation therapy. The complexity of managing warfarin has led to the development of a variety of specialized models managed by pharmacists, physicians, nurses, and self-managed care. The aim of the study is to compare the effectiveness of pharmacist-managed anticoagulation control of warfarin with other models. MethodsWe performed a systematic literature search of the PubMed, Medline@Web of Knowledge, EMBASE, Cochrane Library and Cumulative Index to Nursing and Allied Health Literature to identify randomized controlled trials (RCTs) from database inception up to July 2015. The search terms used for the study were warfarin', pharmacists', Vitamin K antagonist', anticoagulation' and management model.' We used the Cochrane Collaboration's tool from the Cochrane Handbook to assess the risk of bias of RCTs. We performed statistical analyses using RevMan 5.3 and used the Grading of Recommendations, Assessment, Development, and Evaluations profiler to rate the quality of evidence of the outcomes. The anticoagulation control outcomes were the percentage of time within the standard and expanded therapeutic range and thrombosis events; the safety outcomes were bleeding events and mortality, and patients' satisfaction of anticoagulation service. Results and discussionEight RCTs from 981 potentially relevant publications with a total of 1493 patients were included. Meta-analysis of the RCTs showed that a significant difference existed between pharmacist-managed care and other models for satisfaction (mean difference (MD)=0.41, 95% CI, 0.01-0.81, P=0.04, low-quality evidence) with heterogeneity, and the percentage of time within the standard therapeutic range (MD=3.66, 95% CI 2.20-5.11, P<0.00001, high-quality evidence) without heterogeneity. However, the pharmacist-managed group demonstrated no significant improvement on the percentage of time within the expanded therapeutic range (MD=2.85, 95% CI -0.56 to 6.26, P=0.10, moderate-quality evidence) with heterogeneity, mortality [odds ratio (OR)=0.97, 95% CI, 0.44-2.11, P=0.09, high-quality evidence] without heterogeneity, the prevention of bleeding events (OR=0.89, 95% CI, 0.56-1.44, P=0.64, high-quality evidence) without heterogeneity, and thrombosis events (OR=0.81, 95% CI, 0.34-1.92, P=0.64, high-quality evidence) without heterogeneity. What is new and conclusionThe advantage of pharmacist-managed warfarin anticoagulation therapy in terms of anticoagulation control, safety and mortality are unclear, but resulted in significantly better patient satisfaction. Compared with other models, the superiority of pharmacist-managed warfarin anticoagulation needs to be further evaluated and validated in future research.