Text messaging and home blood pressure monitoring for patients with uncontrolled hypertension: a pilot randomized controlled trial

Objective: Improving adherence to antihypertensive medications is the most significant modifiable patient related factor to achieving blood pressure (BP) control. Elevated BP remains the leading cause of death globally. BP trends show disparities in the burden of hypertension in black and low socioeconomic status (LSES) populations, accompanied by low levels of awareness, treatment and control rates. Telehealth systems using text messaging (SMS) and home blood pressure monitors (HBPM) represent attractive scalable tools to reduce BP in those with health disparities. Design and methods: In three ambulatory clinics that serve a large number of those with LSES affiliated with an academic institution, we conducted a randomized controlled pilot study for low medication adherent patients with poorly controlled hypertension (BP > 130/80). The pilot aimed to (1) evaluate the feasibility of recruiting LSES participants to an effectiveness trial of SMS plus HBPM vs HBPM only; (2) measure the acceptability of the SMS system and (3) estimate the effects of the SMS approach on lowering BP. Satisfaction was measured using the validated systems usability survey (SUS). The SMS system was designed with the input of LSES focus groups and used Twilio® as its bidirectional platform. From February 2021 to October 2021, 24 participants were randomized (1:1) to either SMS intervention plus HBPM with an Omron BP cuff or HBPM alone for 12 weeks. Results: During the study period, the study coordinator enrolled 24 participants, averaging 3 per month. Demographics: participants were male (N = 14/24), predominantly African American (AA); (n = 19/24); 13/24 had high school education or less; mean age 55.7 (SD 12); weight 97.4 kg (SD 14); Mean initial SBP 156 mmHg (SD 20), DPB 100 mmHg (SD 11). Acceptability: 8/12 participants responded via SMS with at least one BP measurement in the SMS arm. Two participants were lost to follow up in each arm. Mean SUS was 81.6 (scale of 0 to 100, > 68 is considered above average). Reduction in SBP at 12 weeks in the SMS group and control group was 15 mmHg and 13 mmHg respectively (p = 0.58). Conclusion: Recruiting and retaining LSES participants with uncontrolled HTN for a larger trial of telehealth with SMS and HBPM is feasible and well accepted. Similar BP reductions were achieved in both arms. Utilizing the SMS and HBPM shows promise in reducing BP in the LSES population. A larger efficacy trial is needed to determine best practice and reduce cardiovascular health disparities.