OBJECTIVE: To test the hypothesis that subjective reports of pain severity, pain intensity and functional disability correlate positively with catastrophizing.PATIENTS: Adults with chronic low back pain for six months or longer presenting to a tertiary care Pain Management Unit.METHODS: Catastrophizing was measured with the Pain Catastrophizing Scale (PCS) in 40 subjects (23 males, 17 females). Functional disability was measured with the Pain Disability Index and pain severity/intensity was quantified with the McGill Pain Questionnaire. Statistical analysis included Student's t test and Pearson correlation analysis.RESULTS: Student's t tests on all dependent variables showed no significant sex differences. Correlational analysis revealed a significant relationship between catastrophizing and pain severity (r=0.35, P<0.05), between catastrophizing and pain intensity (r=0.39, P<0.05), and between catastrophizing and disability (r=0.55, P<0.001). Further analysis revealed the helplessness component of the PCS correlated most strongly with functional disability. Analysis of the relationship between pain intensity and disability revealed no significant relationship.CONCLUSIONS: These observations support the finding that disability in chronic pain results from various causes, and is not solely a function of pain or pathology. The helplessness component of catastrophizing is most strongly related to disability. The implication of this finding is that psychological variables need proper assessment when there is significant disability. The PCS appears to be a useful tool to delineate further psychological components of chronic pain.