ABSTRACT
Anticoagulation with warfarin is under-prescribed in eligible patients. The quality of anticoagulation as measured by Time in Therapeutic Range (TTR) is below the 60-70% standard in clinical practice (outside anticoagulation clinics) with lower rates in SubSaharan Africa when compared with Western Europe, Canada and the United States. WhatsApp is a free smartphone application that is increasingly used for telemedicine applications. In this retrospective study, we reviewed the use of WhatsApp for physician-patient communication of INR results and Warfarin dose adjustments. From March 5th, 2018 to May 15th, 2019, all patients (n=938) attending a private Cardiology clinic were offered WhatsApp as a means of direct communication with the Cardiologist on an as needed basis. 21 (2.2%) used it for INR reporting and Warfarin dose adjustment. The median age was 62 years, with a male to female ration of 10:11. The median TTR was 37% by Linear Interpolation, and 42.9% by percentage of therapeutic INRs. The median follow-up duration was 82 days. 23% of patients managed to achieve TTR of more than 72%. Most patients (61.9%) continued on warfarin during the study period, 9.5% switched to a Directly Acting Oral Anticoagulant, 9.5% stopped Warfarin due to bleeding while on therapeutic INR, 14.2% switched to another provider for INR monitoring, 9.5% were lost to follow-up. Smartphone technology may provide a solution for reduced Warfarin prescription for eligible patients, with some patients (23% in this study) achieving TTRs of more than 72%. However, overall TTR rates remained low in this study