The effectiveness of daily SMS reminders in pharmaceutical care of older adults on improving patients' adherence to antihypertensive medication (SPPA): study protocol for a randomized controlled trial

Background: Despite a variety of efficient and cost-effective antihypertensive medication, hypertension remains a serious health and economic burden. High consumption of cardiovascular drugs in the Slovak Republic does result neither in better hypertension control nor in significant decrease in cardiovascular mortality. At the same time, Slovakia has alarmingly low patients' adherence to medication intake. Studies have shown the efficiency of short messaging service (SMS) reminders to improve patients' adherence and health outcomes at low costs. Since SMS is popular among Slovaks, this approach may be feasible also in Slovakia. The primary objective is to assess if daily SMS reminders of antihypertensive medication intake provided by pharmacists in addition to the standard pharmaceutical care increase the proportion of adherent older hypertensive ambulatory patients. Methods: The SPPA trial is a pragmatic randomized parallel group (1:1) trial in 300 older hypertensive patients carried out in community pharmacies in Slovakia. Trial pharmacies will be selected from all main regions of Slovakia. Trial intervention comprises daily personalized SMS reminders of medication intake embedded into usual pharmaceutical practice. The primary outcome is a combined adherence endpoint consisting of subjective self-reported medication adherence via the eight-item Morisky Medication Adherence Scale (MMAS-8) and objective pill count rate. Secondary outcomes include: change in the MMAS-8; comparison of adherence rates using pill count; change in systolic blood pressure; and patient satisfaction. Also, direct treatment costs will be evaluated and a cost-effectiveness analysis will be carried out. Discussion: The SPPA trial engages community pharmacists and mobile health (mHealth) technologies via evidencebased pharmaceutical care to efficiently and cost-effectively addresses current main healthcare challenges: high prevalence of hypertension; overconsumption of cardiovascular medicines; low adherence to medication treatment; and resulting uncontrolled blood pressure. The results may identify new possibilities and capacities in healthcare with low additional costs and high value to patients.