Psychometric Properties of a Korean Version of the Pain Anxiety Symptoms Scale-20 in Chronic Pain Patients

The Pain Anxiety Symptoms Scale (PASS-20) consists of 20 items designed to assess four aspects of pain-related anxiety: cognitive anxiety, escape-avoidance behaviors, fear of pain, and physiological symptoms of anxiety. Although the PASS-20 is a well-established measure of pain-related anxiety in Western samples, different cultures may yield a different factor structure or different associations with pain-related outcome variables. The purposes of this study were (1) to examine the factor structure of a Korean language version of the PASS-20 (KPASS-20); (2) to examine reliability and construct validity of the KPASS-20; and (3) to compare the findings of this study with those of the original psychometric study using a Western sample. A total of 166 patients seeking treatment in a university pain management center located in Seoul, Korea participated. Results indicated that the KPASS-20 consists of three factors, "fearful thinking," "physiological response," and "avoidance," and has adequate reliability and construct validity estimates. On the mean total score of the KPASS-20, the Korean sample had a significantly higher score than the original Western sample. In addition, in correlation analyses between the total score of the KPASS-20, physical functioning, and pain severity, the Korean sample had significantly higher coefficients, whereas similar differences were not found in the analyses of psychological functioning and depression. The findings provide preliminary support for the reliability and validity of the KPASS-20.