Comprehensive measurement invariance of alcohol outcome expectancies among adolescents using regularized moderated nonlinear factor analysis

Alcohol outcomes expectancies (AOEs) are robust predictors of alcohol initiation and escalation of drinking behavior among adolescents. Although measurement invariance is a prerequisite for inferring valid comparisons of AOEs across groups (e.g., age), empirical evidence is lacking. In a secondary data analysis study, we employed regularized moderated nonlinear factor analysis (MNLFA) to simultaneously test differential item functioning (DIF) across age, sex, race, ethnicity, socioeconomic status (SES), and alcohol initiation for a 22-item, two-factor measure of positive and negative AOEs among adolescents (analytic n = 936 drawn from a parent study of 1023 adolescents). Evidence of DIF was minimal, with no DIF for the negative AOE factor and DIF for only two items of the positive AOE factor. The item “feel grown up” exhibited DIF by age, and the item “feel romantic” exhibited DIF by SES. After accounting for DIF, the positive AOE latent factor mean differed by SES, age, and alcohol initiation, and exhibited lower variability by alcohol initiation. The negative AOE latent factor mean differed by sex and SES, with greater variability by SES and age and lower variability by alcohol initiation. Group-differences findings for age and alcohol initiation are consistent with prior work, and differences by sex and SES are a new contribution to the literature that should prompt additional research to ensure replicability. The present study demonstrates the utility of the MNLFA technique for examining comprehensive measurement invariance, particularly for applied researchers who seek to examine substantive research questions while accounting for any DIF present in the scales used.