Background: Managing the chronic illness type 1 diabetes (T1D) is extremely demanding, especially during adolescence. Self-efficacy is belief in one's own capabilities and this is crucial for diabetes management. Having a valid method for measuring self-efficacy is important.
Objective: Our aims were to psychometrically validate a Danish version of the self-efficacy in diabetes management (SEDM) questionnaire, and to examine the relationship between background variables and self-efficacy.
Methods: All Danish adolescents with T1D (n = 1075) were invited to participate in our study. In total, 689 agreed to participate and 602 completed the study. Data were collected using a web-based survey. All participants were asked to provide a blood sample for HbA1c measurement. Graphical log-linear Rasch modeling (GLLRM) was used to validate the questionnaire and its reliability was assessed using Monte Carlo simulation.
Results: We found the questionnaire to be valid and reliable, but it had a dual structure that suggested a need for 2 separate subscales. One subscale related to practical (SEDM1) and the other to emotional (SEDM2) aspects of diabetes management. Both subscales were targeted toward adolescents with lower self-efficacy and were associated with HbA1c. SEDM1 was influenced by treatment modality and age. In SEDM2 we found an interaction between age and sex.
Conclusion: The Danish version of the SEDM questionnaire should be divided into two parts, each with a valid and reliable subscale for self-efficacy measurement. The relationship between self-efficacy and age seems to differ between boys and girls.
Keywords: adolescent; diabetes mellitus type 1; reproducibility of results; self-efficacy; sex characteristics.
© 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.