Improving treatment adherence for blood pressure lowering via mobile phone SMS-messages in South Africa: a qualitative evaluation of the SMS-text Adherence SuppoRt (StAR) trial
BACKGROUND
Effective use of proven treatments for high blood pressure, a preventable health risk, is challenging for many patients. Prompts via mobile phone SMS-text messaging may improve adherence to clinic visits and treatment, though more research is needed on impact and patient perceptions of such support interventions, especially in low-resource settings.


METHOD
An individually-randomised controlled trial in a primary care clinic in Cape Town (2012-14), tested the effect of an adherence support intervention delivered via SMS-texts, on blood pressure control and adherence to medication, for hypertensive patients. (


TRIAL REGISTRATION
ClinicalTrials.gov NCT02019823). We report on a qualitative evaluation that explored the trial participants' experiences and responses to the SMS-text messages, and identified barriers and facilitators to delivering adherence support via patients' own mobile phones. Two focus groups and fifteen individual interviews were conducted. We used comparative and thematic analysis approaches to identify themes and triangulated our analysis amongst three researchers.


RESULTS
Most participants were comfortable with the technology of using SMS-text messages. Messages were experienced as acceptable, relevant and useful to a broad range of participants. The SMS-content, the respectful tone and the delivery (timing of reminders and frequency) and the relational aspect of trial participation (feeling cared for) were all highly valued. A subgroup who benefitted the most, were those who had been struggling with adherence due to high levels of personal stress. The intervention appeared to coincide with their readiness for change, and provided practical and emotional support for improving adherence behaviour. Change may have been facilitated through increased acknowledgement of their health status and attitudinal change towards greater self-responsibility. Complex interaction of psycho-social stressors and health service problems were reported as broader challenges to adherence behaviours.


CONCLUSION
Adherence support for treatment of raised blood pressure, delivered via SMS-text message on the patient's own phone, was found to be acceptable, relevant and helpful, even for those who already had their own reminder systems in place. Our findings begin to identify for whom and what core elements of the SMS-text message intervention appear to work best in a low-resource operational setting, issues that future research should explore in greater depth.