Psychometric evaluation of the Persian version of the adult Nine Item ARFID screen (Persian- NIAS)

Abstract

Background Avoidant/restrictive food intake disorder (ARFID) is an eating disorder characterized by restrictive eating that leads to weight loss or failure to grow, nutritional deficiency, supplement dependence, and/or psychosocial impairment. The aim of the present study was to culturally adapt and investigate the psychometric properties of the Persian version of the adult Nine Item Avoidant/Restrictive Food Intake disorder screen (NIAS), among general population of Iranian adults. Methods This methodological cross-sectional study was conducted among 936 Persian-speaking adults, living in Isfahan, Iran. Translation of the NIAS was performed using forward-backward method. Intra Class Correlation (ICC) and Cronbach's alpha were used to assess test-retest reliability and internal consistency, respectively. Construct validity was investigated by using exploratory factor analysis (EFA), and confirmatory factor analysis (CFA). Convergent and divergent validity was determined using BMI, adult eating behavior questionnaire (AEBQ), and Hospital Anxiety and Depression Scale (HADS). Results Persian version of the NIAS showed excellent test-retest reliability in all domains (ICCs: 0.989-0.995). The computed Cronbach's alpha coefficients for dimensions of Persian-NIAS were in the range good to excellent (alpha: 0.803-0.879). Persian-NIAS showed good known-group validity and differentiated persons with different levels of BMI from each other (P < 0.05). Construct validity evaluated by EFA led to extraction of three factors (picky eating, appetite, and fear), and the CFA confirmed the adequacy of extracted construct from EFA (CFI = 0.979, TLI = 0.958, SRMR = 0.037 and RMSEA = 0.077). Convergent and divergent Validity revealed significant positive or negative correlations between Persian-NIAS dimensions and different dimensions of the AEBQ, and HADS. Conclusions The Persian version of the NIAS is a reliable and valid instrument with applicability in a broad range of the population of Persian-speaking adults for assessing AFRID eating disorders in research projects.