Improving the Recruitment and Retention in the Intensive Diabetes Prevention Program at Hong Kong in District Health Centers

Objectives: The IDPP provides lifestyle support for people with prediabetes at DHCs in Hong Kong. However, low recruitment and retention limit its impact. This study aims to examine whether optimized implementation strategies improve recruitment and retention while maintaining or improving participants' health outcomes.

Hypotheses to be tested: Compared with usual program delivery. optimized implementation strategies will improve recruitment. retention, and other outcomes while maintaining the clinical outcomes.

Design and subjects: This is a implementation study using a two arms cluster randomized controlled trial. The study will recruit 170 adults aged 18 or above with prediabetes.

Instruments: Program records and structured checklists will assess participation and delivery of the implementation strategies. The Chinese Patient Perceptions of Empowerment Scale and the Chinese 12-item Short Form Health Survey version 2 will assess empowerment and quality of life. Interviews will explore participants' and staff members' experiences.

Intervention: The intervention group will receive the one-year IDPP with enhanced nurse consultations, staff training, appointment reminders, and follow-up after missed appointments. Nurse consultation will include personal goal-setting and shared decisions about lifestyle changes. The control group will receive the usual local IDPP services.

Main outcomes: The primary outcomes are recruitment and retention rates. Other implementation outcomes include acceptability, adoption and sustainability. Secondary health outcomes include blood sugar control, BMI, quality of life and empowerment.

Data analysis: Generalized estimating equations will examine changes in clinical outcomes over time and differences between groups. Recruitment and retention rates will be compared between groups. Interview will undergo thematic analysis.

Expected results: The optimized strategies are expected to help more people join and remain in the IDPP while maintaining or improving health outcomes. The findings will inform the delivery and long-term use of diabetes prevention services in community settings.

Participant will receive the one year IDPP with enhanced nurse consultations and follow-up.

Behavioral: IDPP With optimized Implementation Strategies

Participants will receive the one year IDPP according to existing DHC services.

Behavioral: Usual IDPP

The implementation includes an enhanced nurse consultations. Nurses will help participants understand prediabetes, set personal goals and review lifestyle changes. DHC staff will send reminders three days before scheduled consultations. Provider training and ongoing feedback will support program delivery.

The usual IDPP offers four voluntary group education sessions delivered by DHC staffs. There is also a nurse consultation at the DHC.

Plazo: 12 - month

Feasibility (Primary outcome: Recruitment and Retention rates) Recruitment will be calculated as the proportion of eligible patients who agree to participate in the IDPP out of the total eligible population that reached the DHCs.

Retention rate will be defined as the proportion of participants who complete both nurse consultation sessions and at least two of the four group-based educational sessions over a one-year period.

Plazo: 12 - month

Acceptability will be evaluated using semi-structured interviews with participants and providers following the implementation phase.

Plazo: 12 - month

Adoption will assess the extent to which participants and providers engage with and adhere to the optimized IDPP strategies.

Plazo: 12-month

The perceived relevance and compatibility of the implementation strategies with participant needs, existing workflows, and center resources. Data will be collected through semi-structured interviews with participants and staff.

Plazo: 12 - month

Fidelity, or the extent to which the implementation strategies are delivered as consistently and as intended

Plazo: 12 m- month

Implementation cost will be assessed from an organizational perspective, capturing direct cost associated with delivering the optimized IDPP. Data will be collected through tracking staff time and operational expenses, and by conducting analysis of incremental cost-effectiveness.

Plazo: 12 - month

Sustainability will be assessed as the extent to which the optimized strategies remain integrated into routine DHC operations after external research support ends.

Plazo: Baseline, 6-month, 12-month, 18-month

Mean change in HbA1c level will be measured from blood samples drawn by DHC nurses and analyzed to reflect average blood glucose levels over the previous 2-3months.

Plazo: Baseline, 6-month, 12-month, 18-month

Change from baseline in BMI, calculated as weight in kilograms divided by height in meters squared.

Plazo: Baseline, 6-month, 12-month, 18-month

Lipid profile ( including cholesterol level, high-density lipoprotein, and low-density lipoprotein) will be collected by DHC nurses.

Plazo: Baseline, 6-month, 12-month, 18-month

Perceptions of empowerment will be measured using the Chinese version of the Patient Perceptions of Empowerment Scale (PPES) , an 11-item validated tool with a content validity index of 0.93. The PPES evaluates empowerment across four domains: information (three items), decision-making (two items), individualized autonomy (three items), and staff-management (three items). This tool has proven reliable for assessing empowerment in clinical and research settings.

Plazo: Baseline, 6-month, 12-month, 18-month

QoL will be assessed using the Chinese version of the 12-item Short Form Health Survey version 2 (SF-12), which has demonstrated reliability in local populations.

Plazo: Baseline, 6-month, 12-month, 18-month

Health services utilizations will be assessed by tracking unscheduled visits to general outpatient departments, general practitioners, emergency departments, and hospitals during the six months preceding each data collection timepoint.

Optimizing Implementation of the Intensive Diabetes Prevention Program in District Health Centres: A Hybrid Type 3 Study to Enhance Recruitment and Retention for Prediabetes Management