Influence of movie smoking exposure and team sports participation on established smoking.

OBJECTIVE To examine the joint effects of movie smoking exposure and team sports participation on established smoking. DESIGN Longitudinal study. SETTING School- and telephone-based surveys in New Hampshire and Vermont between September 1999 through November 1999 and February 2006 through February 2007. PARTICIPANTS A total of 2048 youths aged 16 to 21 years at follow-up. Main Exposures Baseline movie smoking exposure categorized in quartiles assessed when respondents were aged 9 to 14 years and team sports participation assessed when respondents were aged 16 to 21 years. Main Outcome Measure Established smoking (having smoked > or =100 cigarettes in one's lifetime) at follow-up. RESULTS At follow-up, 353 respondents (17.2%) were established smokers. Exposure to the highest quartile of movie smoking compared with the lowest increased the likelihood of established smoking (odds ratio = 1.63; 95% confidence interval, 1.03-2.57), and team sports nonparticipants compared with participants were twice as likely to be established smokers (odds ratio = 2.01; 95% confidence interval, 1.47-2.74). The joint effects of movie smoking exposure and team sports participation revealed that at each quartile of movie smoking exposure, the odds of established smoking were greater for team sports nonparticipants than for participants. We saw a dose-response relationship of movie smoking exposure for established smoking only among team sports participants. CONCLUSIONS Team sports participation clearly plays a protective role against established smoking, even in the face of exposure to movie smoking. However, movie smoking exposure increases the risk of established smoking among both team sports participants and nonparticipants. Parents, teachers, coaches, and clinicians should be aware that encouraging team sports participation in tandem with minimizing early exposure to movie smoking may offer the greatest likelihood of preventing youth smoking.