[A]n adolescent who had smoked just one cigarette at age 11 was twice as likely to be a regular smoker at age 14 than those who had not tried a cigarette at age 11. This was true even for the kids who did not smoke again in the intervening years.
How can the 14 year old be considered a 'regular smoker' when he hasn't smoked in three years?
I assume those were years in which he was 11, 12, and 13?
If it's worth saying, but not worth its own post, even in Discussion, it goes here.