Next, to assess whether these transition patterns varied by age, we compared pathway classifications in the three age cohorts who entered the study at ages 9, 11 and 13 respectively. As Table 1 shows, relative to other pathways to CD, the likelihood of simultaneous CD and ODD onset was stable across cohort and a CD diagnosis with no history of ODD became more usual with increasing age. The ODD→CD pathway, by contrast, became significantly less common across age, relative to the other pathways to CD (OR for a 1 year increase in age =.6, 95% CI: .3, .9, p=.019).
