Effectiveness of mobile phone text messages sent as reminders for self-monitoring of blood pressures and blood glucose at home among low income patients in Kenya: an open label randomized controlled trial

Abstract Background Self-measurements of blood pressure or blood glucose at home are effective in reducing blood pressure or blood glucose among patients with hypertension or diabetes. However adherence to these measurements is poor in low income settings including Kenya. We assessed the effectiveness of mobile phone text message (SMS) reminders for self-measurements on blood pressure, and blood glucose control. Methods This was an open-label randomized controlled trial among low income patients from healthcare facilities in three Kenyan counties (Nairobi, Kiambu, and Vihiga). To be eligible, patients had to be an adult (18 years and above) with a diagnosis of hypertension or type 2 diabetes, own a mobile phone, and accept self-measurements at home. Patients with hypertension were randomized into three arms each with 94 patients receiving daily, weekly, and no SMS respectively. Patients with diabetes were randomized into two arms (weekly versus no SMS) each with 64 patients. The proportion of patients with controlled blood pressure (< 140/90 mmHg), and controlled random blood glucose (< 11∙00 mmol/L) estimated through a survey conducted after 12 months of follow-up were our primary outcomes. Our secondary outcome was the effect of SMS reminders on self-measurements. We used intention to treat analysis. Results Between January and December 2020, 252/282 (86∙2%) patients with hypertension completed the study. The frequency of self-measurements increased among patients with hypertension who received weekly SMS. Using a multivariate Poisson regression, weekly SMS was associated with blood pressure control; RR = 1∙34, 95%CI (1∙01–1∙78) but daily SMS was not associated (RR = 0∙89; 95%CI (0∙63 − 1∙27)]. For diabetes, 104/128 (78∙9%) completed the study and there was no significant effect of weekly SMS on blood glucose control. Conclusions Weekly SMS reminders among patients on blood pressure self-monitoring substantially improved blood pressure control. SMS reminders are recommended as an adjunct intervention to improve adherence to self-measurements of blood pressure at home. Trial registration: This study was registered in the Pan African Clinical Registry (PACTR202003783697033) on 30 Mar 2020.