Chinese versions of the Northoff Catatonia Rating Scale and the Northoff Scale for Subjective Experience in Catatonia

Abstract

Objective Catatonia was increasingly recognized as a transdiagnostic psychomotor syndrome, but validated Chinese tools for multidimensional clinician-rated assessment and patient-reported subjective experience were limited. This study developed Chinese versions of the Northoff Catatonia Rating Scale (NCRS) and the Northoff Scale for Subjective Experience in Catatonia (NSSC) and evaluated their psychometric properties. Methods Participants completed clinician-rated and self-report assessments. Reliability was examined through internal consistency, inter-rater reliability and test-retest reliability. Validity was evaluated using content coverage, factor analyses, correlations with the Bush-Francis Catatonia Rating Scale (BFCRS), the Positive and Negative Syndrome Scale (PANSS) and the Brief Psychiatric Rating Scale (BPRS), known-groups comparisons, receiver operating characteristic (ROC) analysis and NSSC-NCRS associations. Results The complete-case analytic sample included 379 participants, including 181 with catatonia and 198 without catatonia. The NCRS showed good internal consistency (Cronbach's α=0.886; McDonald's ω=0.892), good inter-rater reliability (intraclass correlation coefficient [ICC]=0.784, 95% confidence interval [CI] 0.696-0.849) and excellent test-retest reliability (ICC=0.962, 95% CI 0.944-0.974). It correlated strongly with BFCRS (rho=0.862), showed weaker associations with PANSS and BPRS, and discriminated catatonia with an area under the curve (AUC) of 0.926. The NSSC correlated moderately with NCRS (rho=0.517, 95% CI 0.432-0.595) and differentiated catatonia status (median 12.0 vs 6.0; rank-biserial r=0.572). Conclusion The Chinese NCRS was a reliable multidimensional clinician-rated measure, and the Chinese NSSC provided a complementary patient-reported measure of subjective catatonic experience.