A psychometric evaluation of a Chinese version of the Cardiac Depression Scale

Objective: This study aimed to evaluate the validity, reliability, and cultural relevance of the Cardiac Depression Scale (CDS) as a disease-specific screening tool for Chinese cardiac patients. Methods: The language equivalency and content validity of the Chinese version of the CDS (C-CDS) were evaluated. Measurement performance was tested on 200 Chinese cardiac patients and repeated on 40 patients for test-retest reliability. Results: One item pertaining to sexual activity was removed from the Chinese version due to poor cultural relevance. The C-CDS demonstrated acceptable internal consistency (Cronbach's α of .91 for the total scale and .53-.78 for the subscales). The high correlation (r=.64-.89) between items and the remainder of their own scale provides further evidence of internal consistency. The test-retest reliability was satisfactory with intraclass correlation coefficients of .94 for the overall scale and .73-.92 for the six subscales. The total and subscale scores that were not significantly different (P>.05) over a 2-week period further support the stability of the instrument. There was acceptable concurrent validity with moderate (r≥.3, P<.001) correlations between the C-CDS and the Chinese version of the Hospital Anxiety and Depression Scale. Principal component analysis revealed six factors, and one dimension was extracted from the data set, which closely resembles the structure of the original instrument. Conclusion: Empirical data support the C-CDS as a valid and reliable disease-specific tool in assessing depressed mood in Chinese-speaking patients with cardiac disease.