Psychometric Validation of the Simplicity of Diabetes Treatment Questionnaire (Sim-Q) for Type 2 Diabetes.

INTRODUCTION: Over the past 2 decades, treatment for type 2 diabetes (T2D) has evolved with the introduction of medications that offer greater simplicity. The Simplicity of Diabetes Treatment Questionnaire (Sim-Q™) was developed to assess the simplicity or complexity of treatment for T2D. This study assessed the psychometric properties of the Sim-Q. METHODS: Eight clinical sites in the USA recruited participants treated for T2D with a variety of medications, including oral medications, insulin, glucagon-like peptide 1 (GLP-1) receptor agonists, and a dual glucose-dependent insulinotropic polypeptide and GLP-1 receptor agonist. Psychometric analysis of the Sim-Q focused on item performance, item selection, exploratory factor analysis (EFA), reliability (internal consistency and test-retest), and validity (construct and known-groups). RESULTS: The study included 250 participants (mean age 59.7 years; 54.4% female). On the basis of item performance and EFA, eight items were retained for the Simplicity of Diabetes Management Subscale assessing simplicity of treatment attributes. Two global items assessing simplicity of medication for diabetes and simplicity of overall diabetes management were scored separately. The Simplicity of Diabetes Management Subscale had good internal consistency reliability (Cronbach's alpha 0.90). The Simplicity of Diabetes Management Subscale and two global items had acceptable test-retest reliability (intraclass correlation coefficients 0.80, 0.72, and 0.73). Convergent validity was supported by significant correlations (P < 0.0001) with related measures. The Sim-Q distinguished between groups of participants who differed in their satisfaction with the ease and convenience of their treatment. For example, the two global items differentiated between groups receiving different treatments (tirzepatide and injectable semaglutide). CONCLUSION: The Sim-Q demonstrated good reliability and validity in this psychometric study. This measure may be useful for assessing individuals' perceptions of treatment simplicity in clinical trials and clinical practice.