Assessing the Utility of a Novel SMS- and Phone-Based System for Blood Pressure Control in Hypertensive Patients: Feasibility Study

Abstract

Background: Although hypertension (HTN) is a major modifiable risk factor for arterial damage, blood pressure (BP) remains poorly controlled in the hypertensive population. Telemedicine is a promising adjunct intervention that may complement traditional therapies and improve adherence rates; however, current approaches have multiple barriers to entry, including the use of relatively expensive Bluetooth devices or the dependence on smart phone utilization, which tend to exclude low-income and more elderly populations.

Objective: The aim of this study was to design and implement a new phone call- and short message service text messaging-based intervention, Epharmix's EpxHypertension, in a quality improvement project that demonstrates the feasibility of this system for BP control in a family medicine setting.

Methods: We recruited 174 patients from a community clinic in St Louis from a database of patients diagnosed with HTN. An automated call or text messaging system was used to monitor patient-reported BPs. If determined to be elevated, physicians were notified by an email, text, or electronic medical record alert. Mean systolic BPs (SBPs) and diastolic BPs (DBPs) were compared at the beginning and end of 12 weeks.

Results: After 12 weeks on the system, patients with a baseline SBP of 140 mm Hg or higher reduced SBP by 10.8 mm Hg (95% CI -14.5 to -7.2, P<.001) and DBP by 6.6 mm Hg (95% CI -9.9 to -3.4, P=.002), but no significant changes were observed in overall BPs and BPs in the group with baseline SBP less than 140 mm Hg.

Conclusions: EpxHypertension provides a viable means to control HTN in patients with high baseline BPs despite previous therapy. This community implementation study demonstrates the feasibility of implementing EpxHypertension across a primary care setting without the need for smartphones or Bluetooth-linked BP cuffs. Future studies should evaluate its effectiveness in a randomized control trial compared with standard of care.

Keywords: disease management; eHealth; hypertension; mHealth; primary care; quality improvement; telemedicine; text messaging.

Figure 1

Study flow diagram detailing the stages of the implementation and the number of patients.

Figure 2

Patient satisfaction with message frequency.

Figure 3

Change in self-reported bimonthly average systolic blood pressures (SBPs) for all patients. No response indicates patients who did not report any BPs during the 2-week period.

Figure 4

Change in self-reported bimonthly average systolic blood pressures (SBPs) for patients with a baseline SBP greater than or equal to 140 mm Hg. Within the subpopulation of patients with a baseline greater than or equal to 140 mm Hg, there is a significant decline in the proportion of reported SBP averages greater than/equal to 140 mm Hg. The 44 enrolled patients who did not complete baseline analysis and illogical self-reported BPs because of SMS formatting discrepancies were excluded from the analysis. No response indicates patients who did not report any BPs during the 2-week period.