Development and Pilot Implementation of a Shared Decision-Making Intervention for Type 2 Diabetes Using the Ottawa Framework

Measured by the Control Preferences Scale (CPS) , originally developed by Lauri et al. and translated into Chinese by Ma Lili (2004). The scale consists of two parts: attitude toward participation in treatment decision-making and actual participation in treatment decision-making. This study uses the part measuring actual participation. The Chinese version has a content validity index of 0.890 and a Cronbach's α coefficient of 0.851 for the actual participation subscale. The 12 items reflect the shared decision-making process: items 1, 6, 7, 8, 9 assess weighing pros and cons; item 5 assesses providing information; items 2, 3, 4 assess expressing preferences; items 10, 11, 12 assess final decision-making. Scoring details follow the standard CPS protocol.

Diabetes-related distress measured by the Chinese version of the Diabetes Distress Scale (DDS), translated and revised by Yang Qing et al. (2010). The scale contains 17 items across 4 dimensions: emotional burden (5 items: 1,3,8,11,14), physician-related distress (4 items: 2,4,9,15), regimen-related distress (5 items: 5,6,10,12,16), and interpersonal distress (3 items: 7,13,17). Each item uses a 6-point Likert scale (1=no problem, 6=very serious problem). Scoring criteria: mean dimension/item score <2 = no distress, 2-3 = moderate distress, >3 = severe distress. Cronbach's α=0.9515.

Diabetes self-management behaviors measured by the Summary of Diabetes Self-Care Activities (SDSCA) scale developed by Toobert et al., Chinese version translated by Sun Shengnan et al. The scale contains 13 items across 6 dimensions: general diet (4 items), exercise (2 items), blood glucose monitoring (2 items), foot care (2 items), medication adherence (2 items), and smoking status (1 item). Total score is the sum of all dimension scores, with higher scores indicating better self-management behaviors. Cronbach's α for each dimension ranges from 0.62 to 0.92.

Glycemic control assessed by two complementary indicators: (1) Fasting blood glucose (FBG, mmol/L) - venous blood samples collected after an 8-hour overnight fast, analyzed using the glucose oxidase method, reflecting short-term glycemic status; (2) Glycosylated hemoglobin (HbA1c, %) - venous blood samples analyzed by high-performance liquid chromatography (HPLC), reflecting average blood glucose levels over the preceding 2-3 months. Lower values of both indicators indicate better glycemic control. According to Chinese Diabetes Society guidelines, target FBG is 4.4-7.0 mmol/L and target HbA1c is <7.0% for most non-pregnant adults with type 2 diabetes.

Decision-making satisfaction measured by the Satisfaction with Decision (SWD) scale adapted by Xu Xiaolin (2010). The scale contains 4 dimensions: information, communication and negotiation, decision-making, satisfaction and confidence. It demonstrates good reliability and validity, with a Cronbach's α coefficient of 0.899. Higher scores indicate greater satisfaction with medical decision-making participation.