Clinical Outcomes of Telephone Service for Patients on Warfarin: A Systematic Review and Meta-Analysis
Itsarawan Sakunrag, Kwanjit Danwilai, Piyameth Dilokthornsakul, Nathorn Chaiyakunapruk, Teerapon Dhippayom
Abstract
Objective: To evaluate clinical outcomes of telephone-based service for patients on warfarin. Methods: Five bibliographic databases and gray literature were searched for articles that reported the effects of telephone interventions provided to patients using warfarin compared with those receiving usual clinic-based care. Mean difference (MD) and relative risk (RR) were used to calculate the effects of telephone intervention on time in therapeutic range (TTR) and visit in range (VIR), respectively. Adverse events (AEs) were pooled and reported as incidence rate ratios. Results: A total of 1,840 articles were examined. Eight articles involving 8,087 subjects were included in the quantitative synthesis. The pooled estimates from seven studies showed no difference on TTR between the telephone service group and the usual care group (MD 2.30; 95% confidence interval [CI] −3.56 to 8.16). In addition, VIR in the telephone service group was not different from the usual care group (RR 1.22, 95% CI 0.87–1.71). Moreover, patients in telephone service groups appeared to have a lower incidence of AEs compared with usual care groups. Discussion: Telephone-based service could be considered as an alternative anticoagulant management. However, owing to a lack of evidence from well-designed studies, further high-quality randomized control trials are warranted.