Although the linear model was not the best fitting of those examined, it was the most interpretable, and thus a linear model was adopted, and modified through the freeing of residuals after consulting modification indices. The resulting modified growth model yielded a chi-square of 50.04; df = 37; p > .05. The fit of this model was acceptable, with a comparative fit index (CFI) of .99, and root mean square error of approximation (RMSEA) = .06. Baseline PDA was a significant predictor of the PDA intercept (level at Month 3; B= 0.43; z=4.33; p < .001), but was not a significant predictor of slope. The overall slope was positive (B=.09), indicating that PDA increased modestly over time from the posttreatment point on.
