Background: The optimal control of type 2 diabetes (T2D) is defined by the innate mastery of self-management behaviours. This study is designed to condense the lived experiences of people with T2D in relation to factors 'exterior' to themselves into a universal self-management inventory (Assessment of Self-Management Questionnaire in Diabetes Mellitus-External Reality; ASQ-DM-EX).
Methods: We collected responses to an online and physical survey from people living with T2D through a quantitative cross-sectional study. First, we tested the contextual validity and cultural preciseness of ASQ-DM-EX prototype through a preliminary pilot testing phase. These processes culminated in the development of a 91-item version of the questionnaire which was disseminated widely to evaluate the predictive strength of the ASQ-DM-EX.
Results: All constructs within ASQ-DM-EX showed internal consistencies within good to excellent range (Cronbach's ⍺ = 0.70-0.94), except for the Influence construct (Cronbach's ⍺ = 0.33). An increase in ASQ-DM-EX scores was associated with a reduction in HbA1c control (r = -0.17, P < 0.05). The ASQ-DM-EX model had excellent goodness-of-fit [root mean square error of approximation < 0.01; comparative fit index = 1.00; Tucker-Lewis index = 1.00].
Conclusion: The ASQ-DM-EX is a novel and holistic inventory that broadens the scope of diabetes assessment absent from contemporary self-management tools.
Keywords: behavioural change; health services research; lived experience; psychometric inventory; self-management; type 2 diabetes mellitus; validation.
© The Author(s) 2025. Published by Oxford University Press.