SMS text intervention for uncontrolled hypertension among hypertensive homeless adults in shelter clinics of New York City: protocol for a pragmatic randomised trial study

INTRODUCTION: Uncontrolled hypertension (HTN) is prevalent in persons experiencing homelessness (PEH) and contributes to significant suffering and financial cost. Mobile health approaches such as short messaging service (SMS) texting have led to better control of HTN in the general population. Despite the high utilisation of mobile phones by PEH, SMS texting to support HTN control has not been evaluated among this population. We hypothesise that an SMS testing programme will enhance health communication, information management, outreach and care coordination, and provide behavioural support to address some barriers to HTN management in PEH. METHODS AND ANALYSIS: This study will use a mixed-methods study design to address two objectives: First, it will evaluate, in a randomised controlled trial, the efficacy of a 6-month SMS texting strategy vs an attention control on blood pressure reduction and adherence to medications and clinical appointments in 120 adults PEH with uncontrolled HTN. Outcomes will be measured at 0, 2, 4 and 6 months. Second, it will assess patients’ and providers’ acceptability and experience of SMS texting using semistructured interviews with PEH (n=30) and providers (n=10). The study will be conducted in shelter clinics in New York City in collaboration with community organisations. The primary statistical analysis will be on an intention-to-treat basis. The trial results will be reported as comparative summary statistics (difference in response rate or means) with 95% CIs and in accordance with the Consolidated Standards of Reporting Trials (CONSORT). Interviews will be transcribed, coded and analysed using an inductive grounded theory analysis. ETHICS AND DISSEMINATION: This study has been approved by the Institutional Review Board (IRB) at George Washington University. Written consent will be obtained from participants. The findings will be disseminated in peer-reviewed journals. TRIAL REGISTRATION NUMBER: NCT05187013.