Cigarette smoking among college students: longitudinal trajectories and health outcomes.

INTRODUCTION: Light and intermittent patterns of cigarette smoking are prevalent among U.S. college-aged individuals. It is unclear whether intermittent smokers maintain their use over time or are transitioning to daily use or nonuse, and whether they experience more adverse health outcomes than nonsmokers.
METHODS: This study examined the trajectories of tobacco cigarette smoking, their predictors, and health outcomes among students (N = 1,253) assessed during their first year of college (Y(1)) and annually thereafter (Y(2), Y(3), and Y(4)).
RESULTS: In Y(1), 3.4% smoked daily and 4.1% exhibited signs of dependence (first cigarette within 30 min of waking). Growth curve modeling identified five distinct smoking trajectories. After stable nonsmokers (71.5%(wt)), the low-stable smoking trajectory was the most common (13.3%(wt)), outnumbering both low-increasing (6.5%(wt)) and high-stable smokers (5.5%(wt)) by 2:1 and high-decreasing smokers (3.2%(wt)) by 4:1. The likelihood of maintaining a low level of smoking over time was inversely related to Y(1) smoking frequency. Few demographic, smoking, and alcohol use characteristics measured in Y(1) distinguished low-increasers from low-stable smokers or high-decreasers from high-stable smokers. By Y(4), high-stable smokers rated their health significantly worse than all others except low-increasers. High-stable smokers had the most Y(4) health problems (i.e., provider visits for health problems and days of illness-related impairment), but only among nonWhites.
CONCLUSIONS: Many college students smoke, but few smoke daily or are nicotine dependent. Intermittent smoking patterns are often stable throughout college and are associated with adverse health outcomes. Prevention strategies should be designed to mitigate the possible long-term health consequences of light and intermittent smoking.