Development and Validation of a Self-Management Motivation Scale for Children with Chronic Diseases.

BACKGROUND: Self-Determination Theory highlights the role of motivation in sustaining self-management behaviors among children with chronic diseases, but validated instruments for assessing this construct in pediatric populations are limited. This study developed and validated a self-management motivation scale for children aged 8-18 years with chronic diseases. METHODS: Scale development proceeded in sequential phases. First, the initial item pool was developed by integrating evidence from relevant literature with findings from semi-structured interviews (n = 22). Second, items were refined through a two-round Delphi consultation with 20 experts to evaluate item importance and relevance, with expert authority and consensus assessed, followed by two rounds of cognitive interviews (n=13) and a pilot survey, yielding a 24-item preliminary scale. Third, item analysis was conducted in 143 children to remove poorly performing items. Finally, psychometric evaluation was performed in 386 children, including content validity, factor structure through EFA (n = 155) and CFA (n = 231), convergent and discriminant validity, internal consistency, split-half reliability, and test-retest reliability (n=30). RESULTS: The final scale comprised 21 items across four dimensions: autonomous motivation, introjected regulation, external regulation, and amotivation. Content validity was strong (I-CVI=0.875-1.000; S-CVI/Ave=0.988). A four-factor structure emerged from the exploratory factor analysis, explaining 75.84% of the variance. Confirmatory factor analysis demonstrated a good model fit (χ2/df=1.755, RMSEA=0.057, CFI=0.965, IFI=0.965, TLI=0.960). AVE ranged from 0.612 to 0.778 and CR from 0.887 to 0.942, supporting convergent validity; discriminant validity was also satisfactory. At the subscale level, Cronbach's α, split-half reliability, and test-retest reliability coefficients ranged from 0.879 to 0.941, 0.865 to 0.932, and 0.763 to 0.944, respectively. CONCLUSION: The scale demonstrated satisfactory reliability and validity for assessing self-management motivation in children with chronic diseases. Further longitudinal and multicenter studies are needed to examine its predictive validity and intervention responsiveness.