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

The aim of the study was to predict smoking from early adolescenceto adulthood by using longitudinal data. The data was gatheredin connection with the North Karelia Youth Project. The projectwas started in 1978 with students in the seventh grade of juniorhigh school (aged 13 years) and finished in 1980 when the studentsreached the ninth grade. The follow-up study included four additionalsurveys over 15 years, the last being in 1993–94. Theresults show that two-thirds of the smokers in the ninth gradeof junior high school (aged 15 years) were still smoking atthe age of 28. About half of the smokers at the age of 28 weresmokers in the ninth grade and the other half had started afterthat. Previous smoking status and smoking by friends were themost important predictors of smoking. The continuity of smokingand non-smoking from adolescence to adulthood supports the importanceof 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 continueafter junior high school.