to other indicators of AUD severity when defined solely in terms of its mildest symptoms. This observation is consistent with findings reported elsewhere (Harford et al., 2009; Kahler and Strong, 2006) that the withdrawal criterion had a low discrimination score and wide dispersion relative to AUD severity, particularly among young age groups. Kahler and Strong (2006) also reported that both sleep problems and vomiting exhibited differential item functioning with respect to sex, reflecting greater severity among women than men, reinforcing the negative psychometric properties of these symptoms as sole indicators of withdrawal.
