Pedersen and Skrondal18 examined the effects of AFD in a school-based cohort of 522 participants. They defined AFD as consumption of a half of bottle of beer, 100 mL of wine or 25 mL of spirits and chart initiation in annual waves of data collection, using the first reported age of drinking as a continuous variable for their analysis. Outcomes were measured in a single follow-up wave at age 18–21 years. After controlling for peer and parental influences in structural equation models they identify a large independent effect, strikingly estimating that a 10% delay in AFD would lead to a 35% reduction in subsequent alcohol consumption and also a large effect on alcohol problems. The authors acknowledged that more stringent control of confounding would weaken this association and that further studies were needed.
