Abstract
Visit non-attendance is a common barrier to hypertension control in low and middle-income countries (LMICs). We aimed to evaluate the effectiveness of mobile text messaging in improving visit attendance among patients with hypertension in primary healthcare facilities in Bangladesh. A randomized A/B testing study was conducted with two patient groups: (1) patients regularly attending visits (regular patients) and (2) patients overdue for their follow-up clinic visit (overdue patients). Regular patients were randomized into three groups: a cascade of three text reminders, a single text reminder, or no text reminder. Overdue patients were randomized into two groups: a single text reminder or no text reminder. 20,072 regular patients and 12,708 overdue patients were enrolled. Among regular patients, visit attendance was significantly higher in the cascade reminder group and the single reminder group compared to the no reminder group (78.2% and 76.6% vs. 74.8%, p < 0.001 and 0.027, respectively). Among overdue patients, the single reminder group had a 5.8% higher visit attendance compared to the no reminder group (26.5% vs. 20.7%, p < 0.001). The results remained consistent in multivariable analysis; adjusted prevalence ratio (PR) was 1.04 (95% CI 1.02-1.06) for the cascade reminder group and 1.02 (95% CI 1.00-1.05) for the single reminder group among regular patients. The adjusted PR for the single reminder group vs. the no reminder group among overdue patients was 1.23 (95% CI 1.15-1.33). Text message reminders are an effective strategy for improving retention of patients in hypertension treatment in LMICs, especially for patients overdue to care.