Study Overview
Objective. To evaluate whether a digital intervention comprising self-monitoring of blood pressure (BP) with reminders and predetermined drug changes combined with lifestyle change support resulted in lower systolic BP in people receiving treatment for hypertension that was poorly controlled, and whether this approach was cost effective.
Design. Unmasked randomized controlled trial.
Settings and participants. Eligible participants were identified from clinical codes recorded in the electronic health records of 76 collaborating general practices from the National Institute for Health Research Clinical Research Network, a United Kingdom government agency. The practices sent invitation letters to eligible participants to come to the clinic to establish eligibility, take consent, and collect baseline data via online questionnaires.
Eligible participants were aged 18 years or older with treated hypertension, a mean baseline BP reading of more than 140/90 mm Hg and were taking no more than 3 antihypertensive drugs. Participants also needed to be willing to self-monitor and have access to the internet (with support from a family member if needed). Exclusions included BP greater than 180/110 mm Hg, atrial fibrillation, hypertension not managed by their general practitioner, chronic kidney disease stage 4-5, postural hypotension (> 20 mm Hg systolic drop), an acute cardiovascular event in the previous 3 months, terminal disease, or another condition which in the opinion of their general practitioner made participation inappropriate.
Of the 11 399 invitation letters sent out, 1389 (12%) potential participants responded positively and were screened for eligibility. Those who declined to take part could optionally give their reasons, and responses were gained from 2426 of 10 010 (24%). The mean age of those who gave a reason for declining was 73 years. The most commonly selected reasons for declining were not having access to the internet (982, 41%), not wanting to participate in a research trial (617, 25%) or an internet study (543, 22%), and not wanting to change drugs (535, 22%). Of the 1389 screened, 734 were ineligible, and 33 did not complete baseline measures and randomization. The remaining 622 people who were randomized in a 1:1 ratio to receive the HOME BP intervention (n = 305) or usual care (n = 317).
Intervention vs usual care. The HOME BP intervention for the self-management of high BP consisted of an integrated patient and health care practitioner online digital intervention, BP self-monitoring (using an Omron M3 monitor), health care practitioner directed and supervised titration of antihypertensive drugs, and user-selected lifestyle modifications. Participants were advised via automated email reminders to take 2 morning BP readings for 7 days each month and to enter online each second reading. Mean home BP was calculated, accompanied by feedback of BP results to both patients and professionals with optional evidence-based lifestyle advice (for healthy eating, physical activity, losing weight if appropriate, and salt and alcohol reduction) and motivational support through practice nurses or health care assistances (using the CARE approach – congratulate, ask, reassure, encourage).
Participants allocated to usual care were not provided with self-monitoring equipment or the HOME BP intervention but had online access to the information provided in a patient leaflet for hypertension. This information comprised definitions of hypertension, causes, and brief guidance on treatment, including lifestyle changes and drugs. These participants received routine hypertension care that typically consisted of clinic BP monitoring to titrate drugs, with appointments and drug changes made at the discretion of the general practitioner. Participants were not prevented from self-monitoring, but data on self-monitoring practices were collected at the end of the trial from patients and practitioners.