Subsequent exploratory analyses considered an alternative way to define diagnostic categories (see Table 2 and Figure 4 c and d). These analyses were guided by the results of the previous analyses suggesting that the alcohol abuse and dependence symptoms comprise a single factor, the severity signals of the symptoms are interspersed, and the current diagnostic system does not optimally reflect differences in AUD severity. Under the alternative diagnostic algorithm, 0 or 1 endorsed abuse or dependence symptoms results in no alcohol diagnosis, 2 or 3 symptoms results in an abuse diagnosis, and 4 or more symptoms results in a dependence diagnosis. Figures 4 c and d clearly indicate that all of the inconsistencies for total symptom count, and the vast majority of the inconsistencies in IRT-based severity of AUDs are eliminated under this alternative diagnostic algorithm. AUD severity is approximately 0–1 SDs above the mean for those without a diagnosis, 1–2 SDs above the mean for those with an abuse diagnosis, and 2 or more SDs above the mean for those with a dependence diagnosis.
