Shop-to-Stop Hypertension: A multicenter cluster-randomized controlled trial protocol to improve screening and text message follow-up of adults with high blood pressure at health kiosks in hardware retail stores.

High blood pressure (BP) is the leading preventable risk factor for death, but only one in three patients achieve target BP control. A key contributor to this problem is poor population awareness of high BP, as the majority of patients are asymptomatic. The Shop-To-Stop Hypertension study is a multicenter, cluster-randomized controlled trial to identify, refer and follow adults in need of hypertension care, whilst raising population-wide awareness. In participants with high BP measured by SiSU Health Stations located in major hardware chain stores across New South Wales, Australia, we will determine whether text message-based nudges will encourage repeat BP checks and visits to their doctor. Based on pilot data, we anticipate 65,340 participants will be screened over 12 months, of which 18% will have high BP. Thirty hardware stores will be randomized (1:1) to: (i) Intervention: participants detected with high BP (≥140/≥90 mmHg) will receive text message-based nudges to return for a repeat SiSU Health Station BP check and to visit their general practitioner (GP) to check and manage their BP; (ii) Control: participants with high BP will not receive text messages. The primary outcome is the difference in the proportion of participants with high BP having a repeat BP check at hardware Health Stations in the intervention vs. control group at 12 months. This novel setting for screening utilises a novel 'citizen science' approach inviting the general public to perform their own BP screening at health kiosks and foster behavioral change. This will allow screening in a low-stress environment.