Secondly, results from the IRT analyses showed that in all EDs the current DSM-IV criteria tap people in the middle-upper end of the alcohol use disorder continuum. Data on alcohol consumption (amount and frequency of use) can be used in all EDs with the current DSM-IV diagnostic criteria to help tap the middle to lower part of this continuum, as first reported by Saha [6]. Nevertheless, as expected, there is no single alcohol consumption measure that is, by itself, invariant (both on severity and discrimination values) within these diverse ED populations. Even when in all ED samples a single dimension of alcohol use disorders exists and alcohol consumption may be used to tap people at the low end of the continuum, differences in severity and discrimination was observed across samples in some of the 11 alcohol use disorder criteria and in three of the four alcohol consumption variables. Prior qualitative research in the scope of current nosological classifications [30] and quantitative analyses at the criterion level for an alcohol dependence diagnosis [31] has warned that not all criterions are similarly
