Adaptive intervention to improve self-management behaviours among hypertensive patients in rural primary care settings: protocol for a Sequential Multiple Assignment Randomised Trial (SMART).

Hypertension blood pressure control rates remain low in rural China, primarily due to inadequate self-management behaviours among patients.

• The study identifies hypertension as 'a major public health challenge in rural China'.
• Physician-patient interaction is identified as a critical mechanism for shaping self-management behaviours.
• Few interventions leveraging physician-patient interaction and tailored to individual behavioural trajectories have been implemented in rural primary care.

The trial uses a SMART design with two initial intervention strategies tested in the first stage.

• Strategy 1 is a standard strategy involving monthly interactive follow-ups.
• Strategy 2 is an enhanced strategy incorporating behavioural incentives into the standard protocol.
• 320 patients were recruited from 16 villages and randomised to either strategy.
• All interventions are delivered via a Smart Medical Assistant Telephone Robot (SMAT-R) integrated within routine primary care services.

After 6 months, patients are assessed for response and non-responders are re-randomised to one of two more intensive intervention strategies.

• Patients with adequate improvement continue their original strategy.
• Patients with suboptimal progress are re-randomised to either an enhanced intervention with a reminder or a further version with both the reminder and physician feedback.
• This constitutes the second stage of the SMART design.

The primary outcome is patient self-management behaviour, assessed using the Hypertension Patient's Self-Management Behaviour Rating Scale.

• Secondary outcomes include blood pressure, quality of life, and acceptability of the intervention.
• Data will be collected at baseline, 6 months, and 12 months post-implementation.
• Secondary outcome data will be collected by trained personnel using standardised procedures and the SMAT-R digital system.

Marginal structural models will be used to assess the dynamic effects of the adaptive intervention.

• The SMART design will 'generate evidence on optimal sequencing and tailoring of strategies based on behavioural responses'.
• The analytic approach is intended to handle the dynamic, two-stage nature of the intervention assignments.
• The trial is registered on ClinicalTrials.gov as NCT06869031.

The trial was approved by the Ethics Committee of West China Fourth Hospital and West China School of Public Health, Sichuan University.

• Ethics approval reference: Gwll2024130.
• The study was conducted in accordance with the Declaration of Helsinki.
• All participants provided written consent before participation.
• Trial results will be shared through peer-reviewed publications, ClinicalTrials.gov, and with healthcare providers and local health authorities, without publication restrictions.