problems were no longer significant. Of the significant associations between AFD at ages 15-17 and the various outcomes, only one -- drinking more or longer than intended -- remained significant, with the others both losing significance and being slightly reduced in magnitude. Although this pattern of results suggests that only the earliest ages at first drink are clearly associated with an increased risk of the incidence of any alcohol problems, such a conclusion must be made with caution, as none of the OR derived from the common risk group were significantly different from their counterparts in Table 2, and loss of significance may have resulted from the reduced sample size upon which the models using the common risk group were based. The results of this experiment do not rule out any of the previous inferences regarding causal mechanisms.
