Reliability, validity and cut-off score of the Chinese version of the panic disorder severity scale self-report form in patients with panic disorder.

BACKGROUND: Panic disorder (PD) is often undiagnosed, misdiagnosed, or untreated in non-psychiatric clinical settings. Therefore, a cost-effective, accurate and easy-to-administer instrument for PD assessment is still needed. For that reason, the self-report version of the Panic Disorder Severity Scale (PDSS-SR) has been developed and suggested to be a reliable and useful tool in clinical and research settings. The current study aims to evaluate the reliability and validity of the Chinese version of the PDSS-SR and determine the cut-off score of the PDSS-SR. METHODS: A total of 133 patients with PD in Shanghai were assessed by the PDSS-SR, PDSS and Hamilton Anxiety Rating Scale (HAMA). Moreover, 117 patients with non-PD anxiety and 51 healthy subjects also completed the PDSS-SR to construct a receiver operating characteristic (ROC) curve with the scores of PD patients. RESULTS: The internal consistency (Cronbach's alpha) of the PDSS-SR was 0.72-0.80, and the interrater correlation coefficient was 0.78. The results of principal component analysis and varimax rotation indicated that the PDSS-SR had a two-factor structure, with all seven items having salient loadings. The cut-off score was 4, which was associated with high sensitivity (96.03%) and specificity (61.31%). CONCLUSIONS: The findings demonstrate that these items and the total score of the PDSS-SR have acceptable reliability and validity in patients with PD and that the PDSS-SR can be used by general doctors for clinical screening in China.