Translation and Evaluation of the Reliability and Validity of Eating Disorder Inventory-3 Referral form Questionnaire Among Iranian University Students: A Cross-sectional Study

Background: Undiagnosed eating disorders may lead to a life-threatening condition, then a validated and reliable tool that lets health providers use it for effective screening is a mandatory need. Objectives: This study aimed to assess the validity and reliability of the Persian version of the Eating Disorder Inventory-3 Referral Form (EDI-3 RF). Methods: In this cross-sectional study, 452 university students and employees were recruited by convenience sampling from the Iran University of Medical Sciences, Tehran, Iran. The content validity was assessed using the five specialists, and then the content validity index (CVI) and content validity ratio (CVR) was calculated separately. The reliability was measured with Cronbach’s alpha and test-retest. Results: Overall, 260 participants filled out the questionnaire completely. The mean age of participants was 22.34 ± 4.18 years. The mean weight was 64 kg (range: 40 - 115). This version of EDI-3 RF yields acceptable content validity and item correlation. According to the expert’s opinion, CVR was more than 0.99 for all inquiries. Also, the CVI for each item was greater than 0.79, which indicates the acceptable value of this index for different items in terms of relevance, clarity, and simplicity. Also, the face validity was approved according to participants’ and experts’ opinions. Cronbach’s alpha for measuring the three subscales of an eating disorder were acceptable (drive for thinness (DT) = 0.76 and 0.77, bulimia (B) = 0.71 and 0.72, and body dissatisfaction (BD) = 0.77 and 0.71, respectively). The correlation coefficient between two questionnaires was 0.48 (P < 0.01). The coefficient between the subscales and whole parts of this questionnaire was 0.58, 0.53, 0.66, 0.48, 0.34, and 0.43, respectively (P < 0.01). Conclusions: This questionnaire would be a beneficial self-response questionnaire, and because of its abbreviated format, it can be used as a screening and referral tool in the Persian population.