Internal consistency and discriminant validity of the Structured Clinical Interview for Panic Agoraphobic Spectrum (SCI‐PAS)

Abstract

AbstractThis paper reports on the feasibility, acceptability and psychometric properties of the Structured Clinical Interview for Panic‐Agoraphobic Spectrum (SCI‐PAS). This interview was designed to assess the lifetime presence of symptoms and other clinical features considered to comprise the panic‐agoraphobic spectrum. The interview has 114 items grouped into nine domains. A total of 422 subjects, from 11 centres located throughout Italy, participated in this study. Data were collected from three groups of subjects: psychiatric patients meeting DSM‐IV criteria for panic disorder (n = 141), cardiovascular patients (n = 140), including 29 with post‐myocardial infarction, and university students (n = 141). The inter‐rater reliability and the internal consistency of the SCI‐PAS measures were assessed using the intra‐class correlation coefficient and the Kuder‐Richardson coefficient, respectively. Discriminant validity was assessed by comparing results in patients with panic disorder to those in the other groups. The interview required an average of 25 (±5) minutes to administer. Patients and clinicians found the scale to be highly useful, providing information not previously obtained. Internal consistency was good (>0.70) for six out of nine SCI‐PAS domains. The inter‐rater reliability was excellent (>0.70) for all the domains except for ‘other phobias’ (0.467). Patients with panic disorder scored significantly higher on each domain, and on the overall panic spectrum, than did the control subjects. In conclusion, the SCI‐PAS is a useful clinical interview, which can be administered in a reasonable period of time. This assessment further demonstrates good internal consistency, discriminant validity, and inter‐rater reliability. Copyright © 1999 Whurr Publishers Ltd.