title: Efficacy of a text messaging (SMS) based intervention for adults with hypertension: protocol for the StAR (SMS Text-message Adherence suppoRt trial) randomised controlled trial.
abstract: BACKGROUND
  Interventions to support people with hypertension in attending clinics and taking their medication have potential to improve outcomes, but delivery on a wide scale and at low cost is challenging. Some trials evaluating clinical interventions using short message service (SMS) text-messaging systems have shown important outcomes, although evidence is limited. We have developed a novel SMS system integrated with clinical care for use by people with hypertension in a low-resource setting. We aim to test the efficacy of the system in improving blood pressure control and treatment adherence compared to usual care.
  
  
  METHODS
  The SMS Text-message Adherence suppoRt trial (StAR) is a pragmatic individually randomised three-arm parallel group trial in adults treated for hypertension at a single primary care centre in Cape Town, South Africa. The intervention is a structured programme of clinic appointment, medication pick-up reminders, medication adherence support and hypertension-related education delivered remotely using an automated system with either informational or interactive SMS text-messages. Usual care is supplemented by infrequent non-hypertension related SMS text-messages. Participants are 1:1:1 individually randomised, to usual care or to one of the two active interventions using minimisation to dynamically adjust for gender, age, baseline systolic blood pressure, years with hypertension, and previous clinic attendance. The primary outcome is the change in mean systolic blood pressure at 12-month follow-up from baseline measured with research staff blinded to trial allocation. Secondary outcomes include the proportion of patients with 80% or more of days medication available, proportion of participants achieving a systolic blood pressure less than 140 mmHg and a diastolic blood pressure less than 90 mmHg, hospital admissions, health status, retention in clinical care, satisfaction with treatment and care, and patient related quality of life. Anonymised demographic data are collected on non-participants.
  
  
  CONCLUSIONS
  The StAR trial uses a novel, low cost system based on widely available mobile phone technology to deliver the SMS-based intervention, manage communication with patients, and measure clinically relevant outcomes. The results will inform implementation and wider use of mobile phone based interventions for health care delivery in a low-resource setting.
  
  
  BACKGROUND
  NCT02019823.
authors.affiliation: University of Oxford, Institute of Biomedical Engineering, Oxford, UK. klbobrow@gmail.com.
authors.forename: Kirsty
authors.initials: K
authors.lastname: Bobrow
authors.forename: Thomas
authors.initials: T
authors.lastname: Brennan
authors.forename: David
authors.initials: D
authors.lastname: Springer
authors.forename: Naomi S
authors.initials: NS
authors.lastname: Levitt
authors.forename: Brian
authors.initials: B
authors.lastname: Rayner
authors.forename: Mosedi
authors.initials: M
authors.lastname: Namane
authors.forename: Ly-Mee
authors.initials: LM
authors.lastname: Yu
authors.forename: Lionel
authors.initials: L
authors.lastname: Tarassenko
authors.forename: Andrew
authors.initials: A
authors.lastname: Farmer
mesh_terms: D000328:Adult; D001071:Appointments and Schedules; D001794:Blood Pressure; D040421:Cell Phone; D006304:Health Status; D006801:Humans; D006973:Hypertension / Q000188:drug therapy*; D055118:Medication Adherence; D017063:Outcome Assessment, Health Care; D010353:Patient Education as Topic / Q000379:methods*; D011788:Quality of Life; D012107:Research Design; D013019:South Africa; D060145:Text Messaging