Point-of-care Capillary HbA1c Testing for Type 2 Diabetes Screening Among At-risk Individuals in Rural Dali, China

This is a cluster randomised controlled trial conducted in rural Dali, Yunnan, China, to evaluate the effectiveness and cost-effectiveness of point-of-care capillary HbA1c testing (POC-cHbA1c) for screening type 2 diabetes among high-risk individuals. The study will involve six township health centres in rural Dali. The intervention group will receive immediate on-site POC-cHbA1c testing, while the control group will undergo fingerstick RBG testing, with both groups having confirmatory vHbA1c testing for validation. Primary outcome is the detection rates of T2DM, while secondary outcomes include the detection rate of pre-diabetes, sensitivity, specificity, and economic evaluations such as the incremental cost-effectiveness ratio (ICER). The findings are intended to inform optimized screening strategies in rural settings, potentially leading to earlier diagnosis, better treatment adherence, and improved health outcomes in rural populations at high risk of diabetes.

• POC-cHbA1c (Diagnostic test): Research staff will use quality-certified POC HbA1c devices to perform finger-prick capillary HbA1c testing for participants. Testing will be completed on site and results will be provided immediately.
• Fingerstick RBG (Diagnostic test): Research staff will use standardised glucometers and test strips to measure fingerstick random blood glucose. Test results will be provided on site.

Primary outcomes

• Detection rate of T2DM [1 week]

Secondary outcomes

• Detection rate of pre-diabetes [1 week]
• Sensitivity and specificity [1 week]
• Number needed to screen [1 week]
• Incremental cost-effectiveness ratio [3 months and 6 months]

Other outcomes

• Proportion of treatment adherence [3 months and 6 months]: Treatment adherence will be measured by the Medication Adherence Report Scale - 5 items, MARS-5
• Score of diabetes self-management [3 months and 6 months]: The level of diabetes self-managment will be calculated as a score using the Summary of Diabetes Self-Care Activities - 6 items (SDSCA-6).
• Venous HbA1c levels [3 months and 6 months]
• Treatment-related adverse event [3 months and 6 months]: Hypoglycaemia, anxiety and depression, etc.
• Level of satisfaction with the screening method [3 months and 6 months]: The level of satisfaction with the screening method will be evaluated using a 5-point Likert item (very disappointed, disappointed, neutral, satisfied, very satisfied).

Sex: All, ages: 18 Years to any

Inclusion Criteria:

* Aged 18 years or above;
* Permanent residents of Dali City who have lived locally for at least six consecutive months;
* Registered as rural residents;
* No known history of diabetes;
* Meet at least one of the high-risk criteria for T2DM specified in the Chinese Guidelines for the Prevention and Treatment of Diabetes issued by the Chinese Diabetes Society;
* Able to understand the study information and provide written informed consent.

Exclusion Criteria:

* Known history of T2DM or currently receiving glucose-lowering treatment;
* HbA1c testing with a clear result within the past three months, or completion of standardised diabetes screening within the past six months;
* Pregnant or breastfeeding at the time of recruitment;
* Active thyroid disease or other active endocrine disorders at recruitment, such as Cushing's syndrome or acromegaly;
* Known haemoglobinopathy, severe anaemia, recent acute blood loss, or history of blood transfusion or blood donation within the past three months;
* Currently receiving treatment that may substantially affect interpretation of HbA1c, such as erythropoietin therapy or recent high-dose iron therapy.

• William Chi Wai Wong, MD, Principal investigator, The University of Hong Kong