The alternative algorithm results in improved discrimination across diagnostic categories as measured by both IRT-based severity estimates (F=4428.56, p<.001, η2=.85) and symptom count (F=2563.91, p<.001, η2=.77). As evidenced by comparing the η2 (i.e., explained variance) for the current DSM-IV algorithm versus the alternative algorithm, the difference in our ability to predict the severity of AUDs is marked, predicting 85% of the variance under the alternative diagnostic algorithm versus 69% under DSM-IV.
