Use of text messages to promote medication adherence and reduce blood pressure in patients with hypertension: the ESSENCE study.

The ESSENCE study evaluated the effect of sending text messages with and without reminders of the time of medication use on adherence to medication treatment and the reduction of blood pressure in patients with hypertension. This was a randomized, crossover, double-blind, active-controlled clinical trial, which included patients aged 30-69 years, followed up at a community pharmacy. Messages were automatically sent using a software and were received on the participants' smartphones. Group 1 included patients who received health information via text messages regarding antihypertensive medications and hypertension control for 90 days, whereas group 2 included those who received information messages along with reminder messages at the time of each drug dose for 90 days. After a 30-day washout period, the groups were switched and received interventions for another 90 days. The 157 evaluated individuals had a mean age of 52 (±8.8) years, and most were female (76.4%). No significant difference was found in intra- and inter-group self-reported adherence in the pre- and post-crossover periods. A significant reduction was found in the pre-crossover period in both groups rather than between the groups for systolic and diastolic blood pressures. At the end of the study, group 1 had a significantly lower mean blood pressure than group 2. However, we could not differentiate which intervention was more effective in terms of outcomes, thus presenting an equivalent effect between the two interventions. These results suggest the possibility of implementing message transmission in health services.