Evaluation of the clinical and safety outcomes of face-to-face vs a telephonic model of a pharmacist-led outpatient anticoagulation service

BackgroundThe traditional method of seeing warfarin patients face-to-face and titrating their international normalized ratio (INR) in anticoagulation clinics has advanced over the years to include an alternative telephonic consultation with expanded collaborative services involving outpatient polyclinics and use of self-testing coagulometers. Objective/SettingThis study evaluated the clinical and safety outcomes of using telephonic vs face-to-face consultation in a pharmacist-led outpatient anticoagulation service at National University Hospital (NUH), a tertiary hospital in Singapore. MethodA retrospective observational study was carried out in patients with atrial fibrillation whose warfarin therapy was managed by either standard or telephonic anticoagulation services. Patients on at least 2 months of warfarin therapy prior to study inclusion were recruited from January to June 2017 and followed up for 6 months. Main Outcome MeasureClinical outcomes included mean INR time in therapeutic range (TTR), INR TTR +/- 0.2 units and +/- 0.5 units variances, mid-point INR TTR, and patients with INR >5 within the 6-month study period. Safety outcomes included thromboembolic events, major bleeding, and clinically relevant nonmajor bleeding. ResultsA total of 152 patients were included in the analysis. The mean TTRs (including the variances) were all not statistically significant between face-to-face and telephonic consultations (TTR: 65.7% vs 64.6%, P = .853; TTR +/- 0.2 variance: 82.3% vs 87.3%, P = .098; TTR +/- 0.5 variance: 95.5% vs 95.9%, P = .966; TTR in 3 months: 66.3% vs 66.0%, P = .723). There were no statistically significant differences between groups in patients with INR >5 within 6 months, thromboembolic, and bleeding events. ConclusionClinical and safety outcomes of telephonic consultation were comparable to face-to-face consultation in the pharmacist-led outpatient anticoagulation service.