Self-oriented and Socially Prescribed Perfectionism: The Psychometric Properties of the Persian Version of the Eating Disorder Inventory-Perfectionism Scale

BACKGROUND: Perfectionism is a key construct for understanding psychopathology. In societies with varying cultures, studying the psychometric properties of tools can help with their external validity. This research aimed at standardization and validation of the Eating Disorder Inventory-Perfectionism (EDI-P) scale in Iran. METHODS: The Persian version of EDI-P was formed through forward translation, reconciliation, and back translation. A total of 302 students were selected using convenience sampling method and’ they completed a set of questionnaires, including the EDI-P, Weight Efficacy Lifestyle Questionnaire-Short Form (WEL-SF), Eating Attitude Test-16 (EAT-16), Self-esteem scale (SES), Difficulties in Emotion Regulation Scale-16 (DERS-16), and Self-compassion scale (SCS) Short Form. The construct validity of the EDI-P was assessed using confirmatory factor analysis and divergent and convergent validity. Internal consistency and test-retest reliability (2 weeks’ interval) were applied to evaluate reliability. LISREL (version 8.8) and SSPS (version 22) software were used for data analysis purpose. RESULTS: EDI-P scales and subscales were found to be a valid and reliable measure, with good internal consistency and good test-retest reliability in the nonclinical sample. Cronbach's alpha coefficient for the whole scale, socially prescribed, and self-oriented were found to be 0.74, 0.68, and 0.67, respectively. Test-retest reliability for the whole scale, socially prescribed, and self-oriented were found to be 0.88, 0.80, and 0.87, respectively. Convergent validity and divergent validity were good (Normed Fit Index [NFI] = 0.94, Incremental Fit Index = 0.95, root mean square error of approximation = 0.08, goodness of fit index = 0.97, Non-normed Fit Index [NNFI] = 0.91, and comparative fit index = 0.95). The results of this study provide support for the two-factor model of EDI-P. CONCLUSION: The EDI-P showed good validity and reliability and could be useful in assessing perfectionism in Iranian population. The EDI-P shows notable promise as a measure for use in eating research and clinical settings.