Twenty-four participants aged 60 years and older will be randomized to either the monitoring intervention or to receive usual care and education; they will be followed-up for 12 weeks. See Figure 1 for patient flow during usual care. The clinicians in the study will identify patients with uncontrolled hypertension during their visits to the clinic. Nurses rooming the patients will record their BP by using an automated BP monitor following the AHA guidelines [16]. The study coordinator will approach prospective patients, that is, those who are 60 years and older, have uncontrolled hypertension (ie, SBP>130 mmHg or DBP>80 mmHg), and have two or more BP medications on their medication list. Nurses will interview the participants in a private room and those with less than college education and with an MAQ score of 0 to 6 will be classified as nonadherent and will be invited to participate in the study. The MAQ cut-off score of ≤6 was chosen for this study because it has been used in previous studies and serves a highly sensitive tool for identifying medication nonadherence [17-19]. Low education has been used a proxy for low socioeconomic status [2]. The study coordinator will assess the potential participant’s phone ownership, text messaging ability, text messaging willingness, and receptivity to the intervention (and record all this information). Participants will be excluded if they have end-stage renal disease (on hemodialysis or peritoneal dialysis), a kidney transplant recipient, unable to afford BP medications, institutionalized (hospice or nursing home care) or unable or unwilling to provide consent to participation in this study (ie, dementia or cognitive impairment), or diagnosed with a terminal illness (eg, cancer, chronic respiratory failure, or requiring oxygen support). Participants who are unable to pay for their medications will be excluded as the study will not provide BP medications. The sample size of 12 patients in each group was chosen based on the feasibility and budget [20] (Figure 2).

Participants will be randomized to the two study groups by using a computer-based random number generating algorithm. Baseline demographic characteristics of the participants will then be collected. All participants will receive a previously validated Omron Bp785n 10 Series arm blood BP monitor and printed instructions in English or Spanish (as per the AHA) on how to perform HBPM [16]. Participants will be instructed on checking their BP at home at least twice a week [21,22]. Text messages used in the intervention were vetted by patients with hypertension in three focus groups held in the Spring of 2019. A programmer will build the SMS text messaging system to be used for the study intervention by using the Research Electronic Data Capture (REDCap)/Twilio platform, keeping a record of the participants contacted via SMS (sent and received messages). Twilio is a cloud communication platform that embeds messaging directly into REDCap. An example of the SMS system is as follows:

If the participants report SBP below 90 mmHg and or above 180 mmHg and/or DBP below 50 mmHg and/or above 120 mmHg on more than one occasion, those numbers will be considered to be outside of the threshold range. These thresholds are made based on the recommendations by AHA/ACC hypertension guidelines, which designate a hypertensive urgency to be 180/120 mmHg or higher and hypotension urgency to be 90/50 mmHg or lower [23]. The study coordinator will be alerted with any outlier BP recordings, who in turn will alert clinicians through an in-basket message in the electronic medical record (Wake One). The patient will then receive an SMS and a phone call and will be prompted to make a clinic visit.

Patients who do not show up to the follow-up visit will be contacted via phone to assess adherence barriers. The study coordinator will create a telephone encounter in the patient’s electronic health record to document their discussion and route it to the patient’s primary care provider. Patients who refuse participation in the study will be asked for the reason, and their responses will be recorded to determine any barriers to participation. The study coordinator will attempt to contact patients who miss follow-up visits every week up to three times; if the patient still cannot be contacted after three attempts, the patient will be considered “lost to follow-up.” Participants will receive a stipend to compensate them for their time in participating in the study.

The personnel performing the outcome assessments will be blinded to the participants’ study assignments.

All statistical analyses will be performed using SAS 9.3 To accomplish Aim 1, we will examine the number of participants enrolled into the study at each study clinic by month over the course of recruitment phase, as well as the average and overall number of participants enrolled per month within each clinic. These rates will assist us in determining the feasibility of recruiting a sufficient sample for the larger trial, and it will potentially inform protocol adjustments. We will estimate additional indicators for feasibility throughout the trial, including measures of retention of participants through the 12 weeks and adherence to the protocol within each group, as well as acceptability of the intervention as measured by the questionnaire (Table 1). We will quantify missing data and dropouts, and we will examine the reasons for ineligibility and discontinuation in the study. For Aim 2, we will examine all data distributions and calculate summary statistics by group using an intention-to-treat approach. Although we will not have adequate statistical power for testing our hypotheses of improved BP control and medication adherence as a result of the intervention, we will conduct an exploratory analysis of any treatment effects (Table 1). An important end product of the trial will be our estimates of variance and correlation for these and other potential outcomes of interest for the larger trial. These estimates will be compared with estimates from studies similar to ours but focusing on other populations and will be used to inform power for the larger trial.

The proposed study presents small risks to participants. They will receive usual medical care. The principal investigator will be responsible for the overall monitoring of the data and safety of the study participants. We will use REDCap, a secure online platform designed for research, to collect all patient data. Participants’ demographics (including their education level), comorbidities, number of medications, number of BP medications prescribed, and BP measures will be extracted from Wake One records when available. The level of education will be confirmed verbally with each participant during consent process. Only one participant identifier will appear in the data collection forms.