Introduction: Catastrophizing is defined as exaggerated negative thoughts during actual or anticipated painful experience. Pain catastrophizing scale (PCS) is a 13 item instrument designed to measure catastrophic thinking. The patient replies to the items according to his/her. Feeling or thoughts when experiencing pain on a 5 point scale. Scones higher than 30 indicate higher probability for chronic pain/disability and necessity for psychological interventions. The original (English) version of the PCS has been shown to be valid and reliable. But to the best of out knowledge; Its Iranian version has not been evaluated yet.
This research was done for assessing validity and reliability of the Farsi version of PCS.
Methods: After taking permission from Professor Sullivan, translation was done according to the standard forward - backward translation method. The preliminary version was completed b 15 volunteers with non - malignant musculoskeletal pain syndromes. They reported no problem with completing the questionnaire and we used it without any change as the final version.
The final version was completed by volunteer patients in three medical centers in Tehran. Validity and reliability was evaluated using the acquired data.
Results: one hundred and sixteen volunteers (64.7% male) participated in the study. Mean (SD) for the participants’ age and PCS scores were 41(0.48) years and 19.7(11.56) points, respectively.
Reliability and validity were assessed using “internal contingency” and “known groups method” respectively. Factor analysis was performed to determine the principal components.
Internal contingency revealed that all three subscales of the Farsi version minimum reliability is 0.93, we can thus conclude that the instrument is reliable.
Known groups method analysis showed that PCS can differentiate subgroups according to sex, so the questionnaire is valid.
Factor analysis identified tow principal components accounted for 58/56% of the variance.
Conclusion: the Farsi version of PCS is valid and reliable in measuring the “pain catastrophizing” in Farsi speaking population.