摘要：Objective. We sought to understand who constitutes the sizable population of nondaily, or some-day (SD), smokers. Methods. We analyzed descriptive statistics and regression results using the 1998–1999 Current Population Survey Tobacco Use Supplement to determine the prevalence of SD smokers, their sociodemographic characteristics, and the smoking patterns and histories of groups differentiated by the length and stability of their SD smoking. Results. SD smokers make up 19.2% of all current smokers. Among SD smokers, 44.6% have smoked less than daily for at least 1 year, no more than 14.4% are just starting to smoke, and the rest are likely in transition. Overall, SD smokers smoked a mean of 102 cigarettes per month (compared to 566.4 for daily smokers), on an average of 14.5 days out of the past 30. Conclusions. SD smokers make up a substantial segment of the smoking population. They are not just beginning to smoke nor trying to quit. Many have developed a long-standing pattern of nondaily smoking, smoking relatively few cigarettes on the days when they do smoke. They are not substantially younger than daily smokers, as one might expect. Until recently, nicotine addiction experts believed that the population of cigarette smokers included few smokers who were able to limit their consumption to just a few cigarettes per day. 1 The notion that a substantial proportion of smokers do not smoke every day seemed even less plausible. However, over the past decade we have learned that as many as one-fifth of current smokers do not smoke on a daily basis. 2– 4 Who are these “unorthodox” smokers, who seem to defy the laws of nicotine addiction as we thought we understood them? Given rising rates of smoking among youth through much of the 1990s and increasing restrictions on and social disapprobation of smoking by adults, one might suspect that these “some-day” (SD) smokers consist primarily, if not exclusively, of smokers in transition: young people beginning to smoke and older adults trying to quit. However, research suggests that many SD smokers may sustain this pattern for at least 1 to 2 years. 3, 4 Until now, we have not known how many of these smokers maintain this pattern for even longer periods of time. SD smoking is important to understand for at least 3 reasons. First, given strong evidence of dose–response effects in smoking and its disease sequelae, 5 SD smokers may well have a lower risk of tobacco-related illness than do daily (“every-day,” ED) smokers, although the same evidence indicates that they will still experience substantially greater risk than nonsmokers. Clearly, it is essential to understand the nondaily pattern to project the burden of smoking-produced disease in the future. Second, the SD smoker phenomenon is of interest in understanding how the changing social environment affects smoking behavior. Restrictions on where cigarettes can be smoked have grown dramatically over the past decade, the result of formal policies pertaining to public places and workplaces as well as informal policies within households. Research finds that such restrictions reduce both smoking prevalence and the daily consumption of continuing smokers. 6– 9 This is consistent with research on drug use in different societies that demonstrates that social context invariably defines how drugs are consumed. 10 A better understanding of SD smokers, both individually and as a group, would help us understand contemporary attitudes about smoking and, eventually, assist in the design of more effective tobacco control policies. Finally, it is important to understand how the SD smoking phenomenon will affect SD smokers’ exposure to cigarettes in the future. Will SD patterns of smoking persist for many smokers? Will they increasingly result in eventual cessation for most? Will many SD smokers lapse into daily smoking? Unfortunately, neither previous research nor the present study can fully address these questions, as none have longitudinal data spanning more than 2 years. However, the current study is able to shed some light on the answer. Knowledge of SD smoking derives primarily from state-specific surveys conducted in the early part of the past decade. 2– 4 The present analysis relies on a more recent (1998–1999) nationally representative sample to examine the phenomenon in its contemporary context. In addition, the detail available in this survey permits a distinction between smokers who have sustained an SD smoking pattern for many years, those in the process of becoming smokers, and those fluctuating among daily smoking, SD smoking, and abstinence. This distinction facilitates better (albeit imperfect) insight on the magnitude and smoking behaviors of these very different groups of SD smokers. The present study addresses 3 questions, updating and extending knowledge gleaned from earlier work: (1) Do SD smokers differ significantly from ED smokers in terms of sociodemographic characteristics and cigarette consumption on those days on which they do smoke? (2) What is the overall prevalence of SD smoking, and how is SD smoking distributed among initiating smokers, those apparently transitioning toward quitting, and smokers with stable smoking patterns? (3) Are there differences in smoking patterns and history among the SD smokers in the initiating, transitional, and stable-pattern groups?
