Age-related smoking progression among adolescents in China

This study examined the differences in smoking progression between middle and upper school students.

The China Seven Cities Study (CSCS) is a longitudinal cohort study. The current sample consists of subjects with both baseline and one-year follow-up measures collected between October 2002 and December 2003. There were 4842 students from 62 middle schools and 5806 students from 83 upper schools. Multilevel random-coefficient modeling techniques were applied.

Among male never or lifetime ever smokers, middle school students were susceptible to transitioning more rapidly than upper school students (never--RR: 1.272, 95% confidence interval [CI]: .985-1.642; lifetime ever--RR: 1.497, 95% CI: .979-2.290). Among female lifetime ever smokers, middle school students were more likely to progress than upper school students (RR: 1.353, 95% CI: 1.038-1.763).

This longitudinal study is the first to explore differences in smoking progression among adolescents in China. The results revealed that over a one-year interval, there was greater progression across smoking trajectories during early adolescence (corresponding to middle school) than later adolescence (upper school). This is consistent with the neurological development hypothesis, but does not rule out alternative explanations. These findings are important to consider relative to the content and timing of prevention interventions in China where smoking rates approach 70% in adult males and are increasing rapidly in women.