Development of computer adaptive tests to assess the psychological status of individuals with an eating disorder or type 2 diabetes.

Background: Individuals with type 2 diabetes and eating disorders must change their eating behaviors, which are often influenced by psychological factors like depression and anxiety. To efficiently assess daily psychological status, the present study aimed to develop computerized adaptive tests (CAT) based on item response theory (IRT).

Methods: Individuals with depression, anxiety disorders, eating disorders, type 2 diabetes, and healthy persons participated in the study. Participants completed six questionnaires, including momentary and most recent one-week depression, anxiety, and positive affect. We selected items meeting the IRT assumptions, applied a graded response model, and conducted CAT simulations.

Results: Across all six questionnaires, the CAT simulations used a smaller number of items and exhibited substantial Pearson's correlation coefficients exceeding 0.95 between simulated and full item-set mood status estimates. These estimated mood scores demonstrated satisfactory concurrent validity with the Hospital Anxiety and Depression Scale and sufficient discriminant validity between the clinical group and healthy controls.

Conclusion: These findings suggest that these scales offer efficient measurement of the mood status of individuals with an eating disorder or type 2 diabetes.