An exploration of the psychometric properties of the PASS-20 with a nonclinical sample

Abstract

The Pain Anxiety Symptoms Scale-20 (PASS-20) assesses 4 factorially distinct components of pain-related anxiety (ie, cognitive, fear, escape/avoidance, physiological). The PASS-20 has good factor stability, reliability, and internal consistency in clinical samples. Psychometric data for nonclinical populations are not yet established. This study had 4 purposes: (1) To assess the factor structure of the PASS-20 with a nonclinical sample; (2) to assess concurrent validity of PASS-20 subscales with related self-report instruments; (3) to compare our results with findings of a similar study using a clinical pain sample; and (4) to suggest a preliminary cut-off score to identify individuals with significantly elevated pain-related anxiety. A sample of 155 undergraduates completed the PASS-20 as part of a larger study. Confirmatory factor analysis supported the existing 4-factor model, and internal consistencies for total and subscale scores were comparable with previous research. PASS-20 total and subscale scores were moderately correlated with other related measures, providing evidence of concurrent validity. On all PASS-20 subscales the nonclinical sample had significantly lower (P < .01) scores than those for a clinical pain sample. The majority of individuals classified as having high pain-related anxiety had PASS-20 total scores greater than 30. Implications and future research directions are discussed.

Perspective: A nonclinical sample is used to explore the psychometric properties of the PASS-20. Confirmatory factor analysis, comparisons with a clinical pain sample, and preliminary cut-off scores indicative of high levels of pain-related anxiety are discussed. Pain-related anxiety is identified as a continuous construct, robust across both clinical and nonclinical samples.