The inflated and count slope factors had means of αis = −.79, p < .01 and αcs = −.04, p < .01 for Caucasian respondents, and αis = −.13, p < .01 and αcs = −.05, p < .01 for African American respondents. The estimated changes based on combined inflated and count slopes are depicted in Figure 1, which shows upward increase from early adolescence to adulthood that then levels off. The Caucasian respondents’ incidence of HED increased at a faster rate than the African American respondents throughout the 20-year age range of this study (i.e., 12 to 31 years old), as suggested by the Wald test of group difference in the count slope (χ2Wald = 145.67, df = 2, p < .01). The variances of these two slope factors were significantly different from zero in both the Caucasian subsample (ψis = .65, ψcs < .00, p < .01) and African American subsample (ψis = .65, ψcs = .00, p < .01), implying that individuals changed differently as age increased yearly.
