Age interacts with heaviness of smoking in predicting success in cessation of smoking.

There is conflicting evidence regarding the relation between heaviness of smoking and the likelihood of quitting smoking. We investigated this issue using the data set of the 1986 Adult Use of Tobacco Survey, a telephone survey of the smoking behavior of noninstitutionalized, civilian, US adults aged greater than 16 years. Analyses were based on a subsample of 4,383 individuals who had made a serious attempt to stop smoking 1-10 years before the survey. Among younger smokers, the lighter smokers (less than 25 cigarettes/day) were the most likely to stop, whereas among older smokers, the heavier smokers (greater than or equal to 25 cigarettes/day) were the most likely to stop. These results indicate that age is an important factor in the relation between heaviness of smoking and success in quitting smoking.