Introduction: Catastrophizing about pain has been identified as one of the most important psychological variables in transition of acute pain to chronic disabling pain. This study aimed at investigating the psychometric properties of a Persian-language version of the pain catastrophizing scale (PCS) amongst a sample of patients with chronic pain.

Materials & methods: This cross-sectional study was conducted on 195 patients with chronic pain using convenience method. Participants completed a group of self-report measures including the Persian versions of PCS, pain severity, daily pain-related interference, physical disability, depression, anxiety, catastrophising, positive and negative effects and pain self-efficacy beliefs. Data were analyzed by Pearson correlation and exploratory and confirmatory factor analysis methods.

Findings: The factor structure of the PCS was examined, using exploratory and confirmatory factor analysis. The results indicated that PCS is conceptualized within a two-factor model, namely magnification and rumination/helplessness. Results also indicated that the PCS and its two subscales have good internal consistency (alphas range from 0.80 to 0.89) and test-retest reliability (rs range from 0.71 to 0.81 (with a 7-14 days interval)). The results of correlation analysis among PCS and its two subscales with measures of pain, interference, disability, depression, anxiety, catastrophising, positive and negative effects and pain self-efficacy beliefs support both the convergent and divergent validity for the PCS and the two subscales of magnification and rumination/helplessness.

Discussion & conclusions: To sum up, the Persian version of the PCS has satisfactory psychometric properties and can be administered amongst the Iranian population with chronic persistent pain.