Reliability and validity of a new post-stroke depression scale in Chinese population.

Background: Nowadays there is still a lack of effective method to evaluate post-stroke depression. To distinguish patients with and without depression after stroke reliably, this study proposes a new Post-Stroke Depression Scale (PSDS).

Methods: PSDS was developed based on various depression scales and clinician experiences. 158 stroke patients who were able to finish PSDS and Hamilton Depression Rating Scale (HDRS) were recruited. Cronbach α, Spearman rank coefficient and Kruskal-Wallis test were respectively used to examine reliability, internal consistency and discriminate validity. Then the Receiver Operating Characteristic (ROC) curve was used to determine the ability of scale and categorized scales to the range of depression. Finally, the factors of the PSDS were classified by average clustering analysis.

Results: The Cronbach α of PSDS was 0.797 (95% CI) indicted a good reliability. The Spearman correlation coefficient between PSDS and HDRS was 0.822 (P<0.001) showed an excellent congruent validity. The discriminate validity displayed significant difference between patients with and without depression (P<0.001). 6/24 was set to be the cut-off value by ROC analysis. Moreover, the different severity was distinguished by the value 6/24, 15/24 and 17/24.

Limitations: The small sample size maybe the main limitation, the larger sample used in different fields according sex, age and side-lesion was needed to verity the results. The cut off value calculated by ROC curve maybe react the severity of the disease to some extent, but it is not absolute.

Conclusions: PSDS is a valid, reliable and specific tool for evaluating post-stroke depression patients and can be conveniently utilized.