Reliability of the self-report version of the Panic Disorder Severity Scale

The interview-administered Panic Disorder Severity Scale (PDSS) has been demonstrated to be a reliable and valid measurement of panic disorder severity. The purpose of this paper is to report on the reliability and usefulness of the self-report form (PDSS-SR). The PDSS and PDSS-SR were administered to 108 psychiatric outpatients with and without panic disorder. The internal consistency of the instruments was analyzed with Cronbach's alpha. Test-retest reliability was assessed on 25 of these subjects by using intraclass correlation coefficient (ICC). In addition, decrease in panic symptoms was measured after cognitive-behavioral treatment (CBT) treatment on 27 subjects. Cronbach's alpha was .917 for PDSS-SR and .923 for the PDSS. The PDSS-SR had good test-retest reliability (ICC=0.81) and was sensitive to change with treatment, with a mean decrease of 7.3 (S.D.=5.1). The self-report version of the PDSS is a reliable format, which could be useful in clinical and research settings. (C) 2002 Wiley-Liss, Inc.