The Pain Anxiety Symptoms Scale Fails to Discriminate Pain or Anxiety in a Chronic Disabling Occupational Musculoskeletal Disorder Population

Abstract

Background: The Pain Anxiety Symptoms Scale (PASS) was developed to measure fear and anxiety responses to pain. Many studies have found associations between PASS scores and self-report measures of pain, anxiety, and disability as well as among inhibited movement patterns and activity avoidance behaviors (eg, kinesophobia). This study aimed to identify clinically meaningful cut-off points to identify high or low levels of pain anxiety and to determine if the PASS provides additional useful information in a functional restoration (FR) treatment program for chronic disabling occupational musculoskeletal disorder (CDOMD) patients. Methods: A consecutive cohort of 551 patients with CDOMD, who entered and completed a FR program, was administered a battery of psychosocial assessments, including the PASS, at admission and discharge. Socioeconomic outcomes were collected 1 year after discharge. After identifying clinical ranges for mild, moderate, and severe pain anxiety, the three groups were compared on self-report measures of psychosocial distress, clinical diagnoses of psychosocial disorders, and 1-year socioeconomic outcomes. Results: Correlations between the PASS and all measures of pain, anxiety, and disability were statistically significant. However, only the Pain Disability Questionnaire showed a large correlation coefficient (r > 0.5). Patients with the highest PASS scores were more likely to be diagnosed with a number of Axis I (depression, opioid dependence) or Axis II (Borderline Personality) psychiatric disorders. They were more likely to display treatment-seeking behavior at 1 year after discharge. However, the PASS failed to differentiate between any other 1-year outcomes. Conclusions: The PASS is elevated when other measures of psychosocial distress are also elevated. However, the PASS fails to discriminate between different indices of depression and anxiety and it is not highly related to 1-year outcomes in a CDOMD cohort. If time and resources are limited, a different measure of psychosocial distress that does relate to socioeconomic outcomes might be a better option in a CDOMD evaluation process.