Juvenile and early adulthood smoking and adult educational achievements--a 31-year follow-up of the Northern Finland 1966 Birth Cohort.

AIMS: To investigate the association between juvenile and early adult cigarette smoking and educational achievements up to the age of 31 years.
METHODS: As a part of the follow-up of the North Finland 1966 Birth Cohort (n = 10542) from 1966 to 1997, smoking was assessed at the ages of 14 and 31 by postal questionnaires. The highest level of educational attainment was obtained from the National Education Registry of Statistics Finland up to the age of 31 years.
RESULTS: Adult smoking (at age 31) and prolonged smoking (at ages 14 and 31) were both associated with an approximately two- to sixfold, adjusted odds for educational underachievement. Smoking only at age 14 showed none of these associations.
CONCLUSION: These results are unlikely to be causal, but may be explained by other characteristics associated with smoking such as personality or lifestyle factors, as well as the effect of knowledge related to smoking gained during higher education.