Psychometric testing of a Mandarin Chinese Version of the Clinically Useful Depression Outcome Scale for patients diagnosed with type 2 diabetes mellitus

Background: The Clinically Useful Depression Outcome Scale (CUDOS) is a self-report instrument that assesses symptoms and the severity of depression, but its psychometric properties in patients with type 2 diabetes mellitus in Chinese-Speaking populations are unknown. Objectives: To examine the psychometric properties of the Mandarin Chinese version of the CUDOS (CUDOS-Chinese). Design: A methodological research design. Setting: Endocrinology and metabolism outpatient clinics at 2 university-affiliated hospitals in northern Taiwan. Participants: Two-hundred and fourteen type 2 diabetic patients with the mean age of 62.6 years were enrolled, and two-hundred and twelve of them completed the study. Methods: Internal consistency, test-retest reliability, concurrent, and contrasted-groups validity were assessed. A receiver operating characteristic curve analysis was performed to assess sensitivity and specificity. Construct validity by means of confirmatory factor analysis was conducted. Results: Internal consistency (Cronbach α of total scale and four subscales. =. 0.93, 0.80, 0.66, 0.80, and 0.83, respectively), test-retest reliability (intra-class correlation coefficients of total scale and four subscales. =. 0.92, 0.89, 0.94, 0.89, and 0.91, respectively), and strong correlations with the Beck Depression Inventory-II (. r=. 0.87) suggested good reliability and validity. The confirmatory factor analysis supported a four-factor model. A cut-off score of 19/20 yielded 77.8% sensitivity and 75.6% specificity. Conclusions: The CUDOS-Chinese demonstrated satisfactory validity and reliability for detecting depression in type 2 diabetic patients in Taiwan.