The relation of the IRT-derived severity score with demographic variables is depicted in Table 2. The severity score was higher among men than women, as was also the case with alcohol dependence but not involvement. The score was negatively related to age, suggesting that younger patients tended to obtain higher alcohol severity scores than older patients. Both alcohol dependence and involvement were also negatively related to age. Conversely, traitedness, or the extent to which people fit the expected pattern of responses, was positively correlated with age, suggesting that older patients were more likely to have an alcohol use trajectory that fits the developmental course of alcohol as defined by the empirically derived model. With regard to ethnicity, White participants had a higher score than Hispanic participants and were less traited than either Hispanic or Black participants. There were no ethnic differences on alcohol dependence or involvement scores.
