Reliability and validity of clinically useful depression outcome scale identifying mixed features in patients with manic episode

Objectives This study aims to explore the reliability, validity, and feasibility of Clinically Useful Depression Outcome Scale (CUDOS) in screening mixed features in patients diagnosed with mania. Methods A total of 109 patients with (hypo-) manic episode were recruited. The reliability of Chinese version of CUDOS (CUDOS-C) were analyzed with Cronbach's alpha and intraclass correlation coefficient (ICC). Spearman correlation coefficient was used to analyze the validity by comparing the correlation between CUDOS-C and Patient Health Questionnaire-9 (PHQ-9), 32-item Hypomania Checklist (HCL-32). The score of MINI (hypo-) manic episode with mixed features-DSM-5 Module-Chinese version(MINI-M-C) >= 2 was considered as the gold standard of mixed features, and the receiver operating characteristic (ROC) curve analysis was used to calculate the optimal cut-off values of CUDOS-C score. Results The Cronbach's alpha value of CUDOS-C was 0.898, and the ICC of CUDOS-C test-retest was 0.880 (95% CI: 0.812-0.923, p < .05).The CUDOS-C score was significantly correlated with PHQ-9 score (r = 0.893, p = .000), but not with HCL-32 score(r = 0.088, p = .364).The area under ROC curve was 0.909 (95% CI: 0.855 to 0.963, p < .001) for CUDOS-C identifying mixed features in mania. The optimal cut-off value was 11 with a sensitivity of 0.854 and a specificity of 0.868. The CUDOS-C (score >= 12) identified 40.4% of the patients with mixed features, which was higher than those diagnosed by clinicians (18.3%) and screened using MINI-M-C (37.6%). Conclusions The results indicate the CUDOS-C is a reliable and valid self-administered questionnaire for assessing depressive symptoms and screening patients with mixed mania.