Figure 1 shows a graph of hazard and survival functions for each milestone, where survival corresponds to failure to reach the milestone. In addition, the timepoint at which the survivor function is .50 (the median, a measure of central tendency) is presented. The median age first drink was reached was ~age 12, with a peak period at age 15. For first drunk and first monthly drink, the median ages were roughly 14 and the peak period of risk for both was ages 14–16. For both first weekly heavy episodic drinking (HED) and daily HED, the peak period of risk was 16, although less than 50% of the sample reached these milestones.
