French adaptation and validation of the Panic Disorder Severity Scale-self-report

Background The aims of this study were to conduct a cross-cultural validation of the Panic Disorder Severity Scale - Self-Report (PDSS-SR) and to examine psychometric properties of the French-Canadian version. Methods A sample of 256 adults were included in the validation study based on data from the baseline interview of a clinical trial on transdiagnostic cognitive-behavioral therapy for mixed anxiety disorders. Participants completed the Anxiety and Related Disorders Interview Schedule (ADIS-5), and self-report instruments including the PDSS-SR, Beck Anxiety Inventory (BAI), Mobility Inventory for Agoraphobia (MIA), Sheehan Disability Scale (SDS), Patient Health Questionnaire (PHQ-9), Social Phobia Inventory (SPIN), Insomnia Severity Index (ISI) and Penn State Worry Questionnaire (PSWQ). The cross-cultural adaptation in French of the PDSS-SR included a rigorous back-translation process, with an expert committee review. Sensitivity to change was also examined with a subgroup of patients (n = 72) enrolled in the trial. Results The French version of the PDSS-SR demonstrated good psychometric properties. The exploratory factor analysis supported a one factor structure with an eigenvalue > 1 that explained 64.9% of the total variability. The confirmatory factor analysis (CFA) corroborated a one-factor model with a good model fit. Internal consistency analysis showed a .91 Cronbach's alpha. The convergent validity was adequate with the ADIS-5 clinical severity ratings for panic disorder (r = .56) and agoraphobia (r = .39), as well as for self-report instruments [BAI (r = .63), MIA (accompanied: r = .50; alone: r = .47) and SDS (r = .37)]. With respect to discriminant validity, lower correlations were found with the SPIN (r = .17), PSWQ (r = .11), ISI (r = .19) and PHQ-9 (r = .28). The optimal threshold for probable diagnosis was 9 for the PDSS-SR and 4 for the very brief 2-item version. The French version showed good sensitivity to change. Conclusions The French version of the PDSS-SR has psychometric properties consistent with the original version and constitutes a valid brief scale to assess the severity of panic disorder and change in severity over time, both in research and clinical practice.

Automated summary

The study aimed to validate the Panic Disorder Severity Scale - Self-Report (PDSS-SR) in a French-Canadian population and examine its psychometric properties. The French version of PDSS-SR demonstrated good psychometric properties and can be used to assess the severity of panic disorder and changes in severity over time in both research and clinical practice.