Background: Data on smoking prevalence from four cross-sectional community-based surveys (1979-1990) are presented for 2,605 adolescents and young adults 12-24 years of age.
Methods: The surveys were conducted in two treatment and two control cities in Northern California as part of the Stanford Five-City Project, a multifactor cardiovascular disease prevention study.
Results: Over the 12-year study period, prevalence of daily smoking declined in all cities by approximately 50% among 16- to 19- and 20- to 24-year-olds but showed little change among those 12-15 years old. Although the declines were especially large in the two treatment cities and in one control city, the declines in treatment cities were not significantly different from those in control cities. During each period, smoking prevalence escalated most sharply between the ages of 12-15 and 16-19, the period of development when students advanced from junior high to high school.
Conclusions: Despite impressive secular declines, it appears that the Five-City Project community intervention, which targeted smoking in adults, did not have a diffusion effect on the tobacco use habits of adolescents.