Abstract
A longitudinal design was used to examine the psychometric properties of the Self-Efficacy for Diabetes Self-Management (SEDM) for children and adolescents with a diagnosis of type 1 diabetes (T1D). The SEDM was adapted to Spanish and the best factorial solution was selected to test the invariance of the measures of age and gender. Individuals between the ages of 10 and 19 years old with a diagnosis of T1D completed a self-reported questionnaire (167 at Time 1 [mean age = 14.49, SD = 2.76; 56.9% boys] and 122 at Time 2 [mean age = 14.77, SD = 2.58; 56.6% boys]). Two unifactorial solutions were tested. The psychometric properties of the scale were validated. The proposed validation obtained excellent reliability indices (χ(2) (26) = 25.59, p > 0.49, RMSEA = 0.00, 95% CI [0.00, 0.07], CFI = 1.00, GFI = 0.96, AGFI = 0.92, TLI = 1.00, and CMIN = 0.98), and it appeared to be invariant for gender and for age groups. The Cronbach's α was 0.85. The test-retest reliability was high (r = 0.69 [p < 0.001]). Convergent, discriminant, and external validity were proven. The nine-item SEDM is a brief measure with satisfactory structural validity. From our knowledge, this study provides the first reliable tool to assess self-efficacy in the management of T1D for Spanish children and adolescents.