摘要：Objectives. We compared smoking quit rates by age in a nationally representative sample to determine differences in cessation rates among younger and older adults. Methods. We used data on recent dependent smokers aged 18 to 64 years from the 2003 Tobacco Use Supplement to the Current Population Survey (n=31625). Results. Young adults (aged 18–24 years) were more likely than were older adults (aged 35–64 years) to report having seriously tried to quit (84% vs 66%, P <.01) and to have quit for 6 months or longer (8.5% vs 5.0%, P <.01). Among those who seriously tried to quit, a smoke-free home was associated with quitting for 6 months or longer (odds ratio [OR]=4.13; 95% confidence interval [CI]=3.25, 5.26). Compared with older smokers, young adults were more likely to have smoke-free homes (43% vs 30%, P <.01), were less likely to use pharmaceutical aids (9.8% vs 23.7%, P <.01), and smoked fewer cigarettes per day (13.2% vs 17.4%, P <.01). Conclusions. Young adults were more likely than were older adults to quit smoking successfully. This could be explained partly by young adults, more widespread interest in quitting, higher prevalence of smoke-free homes, and lower levels of dependence. High cessation rates among young adults may also reflect changing social norms. A key goal of tobacco control is to increase smoking cessation among young adults, because quitting at an early age increases the chances that a smoker will avoid the more serious health consequences of smoking. 1 During the 1980s and 1990s, older smokers (50 years and older) were the most successful quitters, 2 , 3 and annual rates of successful quitting increased for all age groups. 2 However, increases in cessation rates in the 1990s were greatest among young adults aged 20 to 34 years. 2 Furthermore, among young adult smokers, but not older smokers, the increase in cessation rates was higher in states with higher cigarette prices and highest of all in California, which had a comprehensive statewide tobacco control program, 2 suggesting that environmental factors may especially influence cessation rates among young adults. Projecting these national trends, we hypothesized that by 2003, young adults may have been the most successful quitters of any age group. Understanding recent changing influences on successful quitting could help increase the effectiveness of public health programs that aim to encourage cessation. Rates of successful quitting can differ between age groups because of differences in the proportion of smokers who try to quit, or because of differences in success rates among those who try. There is evidence that changes in the social norms surrounding smoking can lead to changes in the proportion of smokers who try to quit and that these norms can be influenced by tobacco-related news coverage 4 and mass media advertising campaigns, 5 both of which increased in the United States in the late 1990s with the Master Settlement Agreement and with the start of the American Legacy Foundation campaign. 6 Young people (aged 0–29 years) may be particularly responsive to such influences, 7 and throughout the 1990s, California’s tobacco control program used targeted media campaigns to specifically influence social norms about smoking. 8 Changes in social norms can also influence behavior associated with success in quitting. In particular, a decrease in levels of nicotine dependence among recent cohorts of smokers could partly explain higher rates of successful quitting among younger adults. Less-dependent smokers are more likely to successfully quit, presumably because of less-intense withdrawal symptoms. 9 – 11 Following the 1992 Environmental Protection Agency report classifying environmental tobacco smoke as a carcinogen, 12 there was a rapid increase in social norms supporting restrictions on smoking, 13 and increased restrictions on smoking at work and in public places have been associated with reduced levels of daily cigarette consumption. 14 , 15 During the 1990s, an increasing proportion of smokers, particularly parents, banned smoking in the home. 16 There is a strong association between smoke-free homes and successful quitting, 17 , 18 perhaps in part because a lapse, for example after a meal, is less likely. It is possible that recent birth cohorts who took up smoking under these restrictions at home and work may develop lower levels of dependence than previous cohorts, 19 and they may themselves be more likely to live in a smoke-free home. During the 1990s, pharmaceutical aids became available to help overcome withdrawal symptoms, and these aids were associated with quitting success. 20 , 21 However, once these aids became easily available over the counter in 1996, their apparent effectiveness in population studies disappeared. 22 , 23 More in-depth analysis has suggested that effective use of pharmaceutical aids may be limited to smokers who are motivated to quit, such as those with a smoke-free home. 24 Thus, differences in patterns of use of pharmaceutical aids between age groups may also contribute to recent differences in quitting success rates. We used a large nationally representative survey to compare US smoking cessation rates and associated tobacco-related behaviors between age groups. We compared attempted quitting rates across age groups each year as well as success rates among those who tried to quit smoking and explored whether there were important differences between age groups in prevalence of known correlates of cessation. We used multivariate logistic regression to establish whether differences in such correlates could account for differences in cessation rates, or whether younger smokers were quitting at higher rates than might be predicted by, for example, lower levels of addiction and a higher prevalence of smoke-free homes.
