AUDIT C trajectory fit, as measured by the Bayesian Information Criterion (BIC), improved substantially when increasing from 3 to 4 groups, but only slightly between 4 and 5 groups. Lower-level group membership was stable, with differences in assignment occurring only at the higher AUDIT-C levels. In the analytic sample, the highest level of the 4-group model contained 98 people. We chose the 4-group model to avoid unstable estimates that could result from using a 5-group model with even fewer subjects in the highest level. The AUDIT-C trajectory groups were designated as infrequent, lower risk, potentially hazardous and consistently hazardous.
