Predicting adult smoking: the influence of smoking during adolescence and smoking among friends and family

Abstract

The aim of the study was to predict smoking from early adolescence to adulthood by using longitudinal data. The data was gathered in connection with the North Karelia Youth Project. The project was started in 1978 with students in the seventh grade of junior high school (aged 13 years) and finished in 1980 when the students reached the ninth grade. The follow-up study included four additional surveys over 15 years, the last being in 1993–94. The results show that two-thirds of the smokers in the ninth grade of junior high school (aged 15 years) were still smoking at the age of 28. About half of the smokers at the age of 28 were smokers in the ninth grade and the other half had started after that. Previous smoking status and smoking by friends were the most important predictors of smoking. The continuity of smoking and non-smoking from adolescence to adulthood supports the importance of prevention programs in junior high school. On the other hand, about half of the smoking adults had started smoking after that. This indicates that the prevention programs should continue after junior high school.