The role of smoking intentions in predicting future smoking among youth: findings from Monitoring the Future data.

AIMS To demonstrate that intentions predict long-term future levels of smoking, irrespective of level of past smoking experience. A growing body of research suggests that intentions about future smoking might play an important role in addition to the influence of past smoking experience on the likelihood of smoking in future. DESIGN Using logistic regression analyses, we assessed the relationship between baseline smoking experience and a firm intention 'not to be smoking cigarettes 5 years from now' with four outcome measures of smoking at follow-up: 30-day smoking at a 3/4- and 5/6-year follow-up and current established smoking (self-described regular smokers or former smokers who had smoked in the past 30 days) at a 3/4- and 5/6-year follow-up. PARTICIPANTS US nationally representative samples of 12th graders who responded to the Monitoring the Future (MTF) survey from the years 1976 to 1993, inclusive. For these panels, we linked stage of smoking and intentions at 12th grade to follow-up measures of smoking collected at 3/4 years after baseline and 5/6 years after baseline. FINDINGS Analysis of 3/4-year follow-up data (weighted n = 4544) and 5/6-year follow-up data (weighted n = 3885) for both definitions of smoking outcome indicated that there was a dose-response relationship between levels of baseline smoking experience and the likelihood of future smoking. In addition, independent of baseline smoking experience, there was a statistically significant protective effect for a firm intention not to smoke in five year's time on future smoking behavior. CONCLUSIONS The findings suggest that evaluative studies of tobacco control policies and programs might usefully employ smoking uptake categories that incorporate smoking intentions as early indicators of outcome.