Optimizing Implementation of the Intensive Diabetes Prevention Program

Recruitment rate will be defined as the proportion of eligible individuals at participating DHCs who are successfully recruited into the study.

Retention rate will be defined as the percentage of enrolled participants who complete both scheduled nurse-led consultations and attend at least two of the four group education sessions within the 12-month intervention period.

Acceptability will be assessed through semi-structured focus group interviews with participants and providers after the implementation phase. Participants will share their satisfaction with key program components, and discuss perceived benefits and challenges. Providers will reflect on the practicality and relevance of the training sessions and enhanced workflows, and how these strategies affected their ability to deliver the IDPP effectively.

Participant adherence will be measured using attendance records from nurse consultations and group workshops.

Provider adherence will be assessed through meeting logs and fidelity checklists that capture consistent application of optimized protocols in clinical practice.

Appropriateness will be evaluated through semi-structured interviews with key stakeholders, including DHC managers, nurses, dietitians, physiotherapists, and participants. Interviews will explore how well the optimized implementation strategies fit within existing DHC workflows, address operational challenges, and support patient engagement.

Fidelity, defined as the extent to which implementation strategies are delivered consistently and as intended, will be assessed using structured performance checklists completed by the PI during random audits of nurse consultations, along with reviews of audio-recorded sessions and provider self-reported logs.

Implementation cost will be assessed from an organizational perspective by capturing direct costs associated with delivering the optimized IDPP. Data will include staff time and operational expenses, with incremental cost-effectiveness analyses conducted alongside sensitivity analyses to test key cost assumptions; results will be presented using cost-effectiveness planes and bootstrapped confidence intervals.

Sustainability will be evaluated by examining the extent to which optimized strategies remain embedded in routine DHC operations after external research support concludes. Focus groups with DHC managers and nurses at the end of the sustainment phase will explore long-term feasibility, while metrics will assess continued use of optimized workflows, provider adherence to protocols, and sustained patient engagement.

Changes in HbA1c, which reflects average blood glucose levels over the previous 2-3 months, will be assessed from blood samples collected by DHC nurses. Results are typically in mg/dL.

Lipid profile (including cholesterol level, high-density lipoprotein, and low-density lipoprotein) will be collected together with the HbA1c from the blood samples drawn by DHC nurses. Results are typically in mg/dL.

Weight will be measured in kilograms (kg), without shoes, and recorded to the nearest 0.1 kg. Body Mass Index (BMI) will be calculated using participants' weight (kg) divided by height (m²).

Height will be measured in meters (m), without shoes, and recorded to the nearest 0.1 cm. Body Mass Index (BMI) will be calculated using participants' weight (kg) divided by height (m²).

Perceptions of empowerment will be assessed using the Chinese version of the Patient Perceptions of Empowerment Scale (PPES). Its scores range from 11 to 55, with higher scores indicating higher perceived empowerment.

Quality of Life will be assessed using the Chinese version of the 12-item Short Form Health Survey version 2 (SF-12v2). Scores on the SF-12v2 range from 0 to 100, with higher scores indicating better quality of life.

Health service utilization will be tracked by documenting unscheduled visits to general outpatient clinics, general practitioners, emergency departments, and hospitals over the six months preceding each assessment point. With participants' consent, utilization data will be obtained from the HA Go and eHRSS platforms and supplemented with self-reported information to ensure completeness.