In all cases, risk increased with lower ERO values. For the onset of regular alcohol use in the entire sample, ERO values were only significant for the group with earliest ages of onset, under 16 years of age. For the onset of regular alcohol use in the illicit drug use subsample, ERO values were significant for the earliest ages of onset, and weakly significant in the oldest age range, over 19 years of age. However, the size of the at-risk group in the oldest age range is so small as to make the results of questionable relevance to the study at large.
