Parallel analyses of diagnostic categories used ODD at wave 1 as the predictor, and CD at any later childhood/adolescent wave as the outcome. Controlling for age and sex, a wave 1 ODD diagnosis predicted later CD diagnosis (OR=7.9, 95% CI: 3.6, 17.6; p<.001). After controlling for baseline levels of CD the relationships were more complicated. Whereas ODD functioned as a clear risk for later CD in boys, effects in girls appeared to be attenuated by a high rate of comorbidity between the two disorders at first assessment, and strong CD persistence. After controlling for wave 1 CD diagnosis, ODD predicted later CD in boys (OR=6.5, 95% CI: 1.8, 23.2; p=.004) but not in girls (OR=.5, 95% CI: .1, 2.3; p=.407) (interaction p=.011). Initial levels of ODD and CD were more strongly related in girls (OR=64.7, 95% CI: 19.6, 213.4; p<.001) than in boys (OR=7.6, 95% CI: 3.4, 16.8; p<.001) (interaction p=.003). Continuity from wave 1 CD to later CD was also stronger in girls (OR=54.8, 95% CI: 13.7, 218.8; p<.001) than in boys (OR=8.6, 95% CI: 3.2, 23.2; p<.001) (interaction p=.032). Controlling for ADHD at wave 1 did not substantively impact upon these results.
