Assessing the reliability and validity of the Slovenian version of the Appraisal of Diabetes Scale (ADS-S) in type 2 diabetes patients

Abstract

Managing type 2 diabetes (T2D) effectively is a considerable challenge. The Appraisal of Diabetes Scale (ADS) has proven valuable in understanding how individuals perceive and cope with their condition. This study aimed to evaluate the psychometric properties of the Slovenian version of ADS (ADS-S). We recruited a sample of 400 adult individuals with T2D from three primary healthcare centers in Slovenia, ensuring an average of 57 cases per individual item. The psychometric evaluation included internal consistency, test-retest reliability, construct validity, and discriminant validity. Confirmatory factor analysis (CFA) was additionally performed to evaluate the fit of one- and two-factor models. After excluding incomplete questionnaires, 389 individuals participated, averaging 72.0±7.5 years, with 196 men and 193 women. ADS-S exhibited acceptable internal consistency (Cronbach’s α = 0.70) and strong test-retest reliability (interclass correlation = 0.88, p <0.001). Criterion validity was established through significant correlations between ADS-S score and EQ-5D utility score (r = -0.34, p <0.001), EQ-VAS score (r = -0.38, p <0.001), and HbA1c >7.5% (r = 0.22, p = 0.019). Discriminant validity assessment found no significant correlation between ADS-S score and age, but a significant correlation with female gender (r = 0.17, p = 0.001). CFA results supported a two-factor structure (psychological impact of diabetes and sense of self-control) over a one-factor structure, as indicated by model fit indicators. ADS-S stands as a valid and reliable tool for assessing psychological impact and self-control in Slovenian T2D patients. Future research should explore adding items for capturing secondary appraisal of diabetes and studying the influence of female gender on ADS scores.