Validity and reliability of the DMSES UK: a measure of self-efficacy for type 2 diabetes self-management

Objectives: Self-efficacy is an important outcome measure of self-management interventions. We aimed to establish UK validity and reliability of the diabetes management self-efficacy scale (DMSES). Methods: The 20 item DMSES was available for Dutch and US populations. Consultation with people with type 2 diabetes and health professionals established UK content and face validity resulting in item reduction to 15. Participants were adults with type 2 diabetes enrolled in a randomised controlled trial (RCT) of the diabetes manual, a self-management education intervention, with an HbA1c over 7% and who understood English. Baseline trial data and follow-up control group data were used. Results: A total of 175 participants completed all 15 items. Pearson’s correlation coefficient of 20.46 (P,0.0001) between the DMSES UK and the problem areas in diabetes scale demonstrated criterion validity. Intra-class correlation between data from 67 of these participants was 0.77, demonstrating test-retest reliability. The correlation coefficients between item scores and total scores were .0.30. Cronbach’s alpha was 0.89 over all items. Conclusion: This evaluation demonstrates that the scale has good internal reliability, internal consistency, construct validity, criterion validity, and test-retest reliability. Practice Implications: The 15 item DMSES UK is suitable for use in research and clinical settings to measure the selfefficacy of people living with type 2 diabetes in managing their diabetes.