Smoking prevalence in a cohort of adolescents, including absentees, dropouts, and transfers.

This study reports daily smoking rates among older adolescents obtained by a unique follow-up of a cohort originally identified in the seventh grade. Those no longer in their original school districts were located and interviewed by telephone. Smoking rates among dropouts exceeded 70 per cent in all age-sex groups. Smoking rates among transfers were as high as those among absentees. Including these subgroups raised smoking prevalence rates among older adolescents substantially.