The Comparative Effectiveness and Safety of Ambulatory Care Warfarin Management by Non-physician Providers Versus Usual Medical Care: A Systematic Review and Meta-analysis.

Introduction: Growing evidence suggests that non-physician providers (NPPs) can effectively and safely manage warfarin therapy. This systematic review and meta-analysis aimed to evaluate warfarin management by NPPs compared to usual medical care (UMC) in ambulatory patients. Methods: We conducted a systematic search of PubMed (MEDLINE), Ovid Embase, Ovid International Pharmaceutical Abstracts, Scopus, CINAHL (EBSCO), and the Cochrane Central Register of Controlled Trials (CENTRAL) from inception to January 2024. Studies were included if they were randomized controlled trials or quasi-experimental designs comparing warfarin management across professions. Two independent reviewers performed title and abstract screening, full-text review, data extraction, and risk of bias assessment. Results were pooled using random effects models. Results: Of 19 122 citations identified, 6 met the inclusion criteria. NPPs included pharmacists (4), nurse practitioners (1), and multidisciplinary teams (1). Meta-analysis showed no significant difference in time spent in therapeutic range (TTR) (mean difference [MD] 1.64%; 95% confidence interval [CI]-1.86 to 5.16, I² = 0%)) for NPPs vs UMC. There were no differences in thrombosis (relative risk [RR] 1.23; 95% CI 0.36 to 4.23, I² = 0%), hemorrhage (RR = 1.07; 95% CI 0.44 to 2.63, I² = 0%), mortality (RR = 0.94; 95% CI 0.33 to 2.67, I² = 0%), or patient satisfaction (standardized mean difference [SMD] 0.56; 95% CI -0.04 to 1.15, I² = 85%). Conclusion: NPP management resulted in similar TTR as UMC. Due to few thromboembolic and hemorrhagic events, more studies are needed to determine the effects of NPP warfarin management on clinical outcomes.