A STUDY OF VALIDITY AND RELIABILITY OF THE PERSIAN VERSION OF THE PADUA INVENTORY-WASHINGTON STATE UNIVERSITY REVISION (PI-WSUR) IN A SAMPLE OF HEALTHY IRANIAN STUDENTS

Objective: Evaluation of the validity of the factor structure of Persian Padua Inventory (PPI) (a measure of obsessive-compulsive phenomena) on a sample of 348 non-clinical students of Tehran University, School of Medicine. Method: Subsequent to translating the questionnaire to Persian and its back translation to original language and final control by the author of the inventory (Burns), a pilot study based on cultural differences was carried out on twenty students. The total subjects participating in this study comprised of 348 individuals in the age range of 18-44 years. The subjects completed PPI, OCI-R, MOCI, BAI, STAI, BDI-II and demographic inventory. Results: The factor analysis of the PPI exhibited eight factors similar but not identical to previous studies: contamination obsessions, washing compulsions, ordering compulsions, checking compulsions, obsessive thoughts about harm to self/others, obsessive thoughts about violence, obsessive impulses to harm self/others, and obsessive impulses to theft. The results of the present study indicate reliability and internal consistency (Cronbach's alpha= 0.92), Spearman splite test (0.95) and test- retest (r=0.77). We assessed the concurrent validity of the PPI in relation to the Obsessive Compulsive Inventory-Revised (OCI-R), and the Maudsley Obsessive- Compulsive Inventory (MOCI) and the results were 0.69 and 0.58 respectively. Conclusion: In correlation with its original version, the PPI is a relatively reliable and valid questionnaire in Iran.