DIF analyses was performed for each of the 11 alcohol use disorder criteria contrasting at the same time severity (thresholds) and discrimination (slopes) parameters (Table 5). Four dependence items (withdrawal, time spent, larger/longer and quit/control) showed heterogeneity across study site (p < 0.05), while three abuse items and three consumption variables showed heterogeneity in threshold estimates. DIF was also found in discrimination (slopes) for two dependence criterions (time spent and phys/psych problems), one abuse criterion (social/interpersonal) and three consumption variables, suggesting heterogeneity of discrimination estimates across EDs sites. Next, the test response curves were plotted to examine whether these item specific differences canceled out in the total alcohol use disorder continuum. The results were very similar for most alcohol consumption variables (with the exception of usual 5+/4+) and suggested that there was no evidence of DIF between study site at the total score level. As an example, Figure 6 shows the DIF results that incorporated the variable 5+ drinks weekly/monthly for men/women. The DIF curves for all sites were virtually identical, suggesting that even if consumption variables had different severities
