Measuring Type 1 diabetes stigma: development and validation of the Type 1 Diabetes Stigma Assessment Scale (DSAS-1)

AIMS: To develop and validate a self-report measure designed to assess perceived and experienced stigma for adults with Type 1 diabetes: the Type 1 Diabetes Stigma Assessment Scale (DSAS-1). METHODS: A large item-pool (64 items) was drafted based on qualitative data from interviews with 27 adults with Type 1 diabetes. Eleven adults with Type 1 diabetes completed the draft questionnaire (responding to items using a five-point Likert scale), and participated in cognitive debriefing interviews. Based on their feedback, the item-pool was reduced and refined. Adults with Type 1 diabetes (N=898) completed an online survey including the draft stigma questionnaire (41 items) and other validated measures. Psychometric validation included principal components analysis and confirmatory factor analysis (split samples), internal consistency reliability assessment and Spearman's rho correlations. RESULTS: Scale reduction techniques resulted in 19 items (α=0.93). An unforced three-factor solution suggested three subscales: Treated Differently (six items, α=0.89); Blame and Judgement (six items, α=0.88); and Identity Concerns (seven items, α=0.89). This was corroborated with a confirmatory factor analysis, which demonstrated reasonable model fit with the three factors; less so for a single-factor model. Satisfactory concurrent, convergent and discriminant validity were demonstrated. CONCLUSIONS: The 19-item DSAS-1 is a valid and reliable measure of the perceptions and experiences of Type 1 diabetes stigma. This novel, relatively brief measure has satisfactory psychometric properties. The DSAS-1 is now available for investigations into the nature and magnitude of the relationships between diabetes stigma and diabetes self-care behaviours and outcomes.