Comparative Properties of Two Self-Report Measures of Avoidant/Restrictive Food Intake Disorder: Psychometric and...

We compared two measures of Avoidant/Restrictive Food Intake Disorder (ARFID)-the NIAS and the PARDI-AR-Q to determine which demonstrates better psychometric and clinical utility.

The study was pre-registered (OSF; DOI 10.17605/OSF.IO/N8WBF). Participants (aged ≥ 18 years, BMI > 18.5) were recruited via Prolific and screened via a short written description of their fussy eating behaviors. After review, eligible participants (N = 156) were invited to complete a second online survey, consisting of the NIAS, PARDI-AR-Q, GAD-7, PHQ-9, CIA, and EDE-Q7. Exploratory factor analyses were conducted separately for the NIAS and PARDI-AR-Q dimensions, and then on combined items. Pearson's correlations examined associations within and across both ARFID measures. Categorical agreement between measures was examined. Correlations and multiple regressions determined the extent to which ARFID subscales accounted for variance across the broader clinical outcomes.

All subscales within and across the NIAS and PARDI-AR-Q were significantly and positively correlated. The weakest association was observed between the NIAS Picky Eating subscale and the PARDI-AR-Q Sensory Sensitivity subscale-a pattern supported by the combined exploratory factor analysis, which yielded a four-factor model. The NIAS and PARDI-AR-Q showed significant, moderate case agreement. The PARDI-AR-Q showed much stronger evidence of clinical validity.

Overall, the PARDI-AR-Q demonstrated greater clinical validity than the NIAS. The weak association between Picky Eating and Sensory Sensitivity suggests these measures capture distinct behavioral and motivational components of ARFID.