A k-means cluster analysis of the 15 standardized variables was used to differentiate Type A and Type B alcoholics. Agreement among the three classification methods was calculated by Cohen’s kappa. The subtypes derived using each of the three approaches [Type A vs. Type B for Babor et al. (1992) or early onset vs. late onset for the two age-of-onset typologies] were compared on baseline characteristics with independent samples t-tests for continuous variables and chi-square [or Fisher’s Exact Test (FET) when cell frequencies were small] for categorical variables.
