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RESEARCH AND PRACTICE |
Donald H. Taylor Jr and Frank A. Sloan are with the Center for Health Policy, Law and Management, Terry Sanford Institute of Public Policy Studies, Duke University, Durham, NC. Vic Hasselblad is with Duke Clinical Research Institute, Duke University. S. Jane Henley and Michael J. Thun are with the American Cancer Society, Atlanta, Ga.
Correspondence: Requests for reprints should be sent to Donald H. Taylor Jr, PhD, 122 Old Chemistry Bldg, Duke University, Durham, NC 27708 (e-mail: dtaylor{at}hpolicy.duke.edu).
| ABSTRACT |
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Objectives. This study determined the life extension obtained from stopping smoking at various ages.
Methods. We estimated the relation between smoking and mortality among 877 243 respondents to the Cancer Prevention Study II. These estimates were applied to the 1990 US census population to examine the longevity benefits of smoking cessation.
Results. Life expectancy among smokers who quit at age 35 exceeded that of continuing smokers by 6.9 to 8.5 years for men and 6.1 to 7.7 years for women. Smokers who quit at younger ages realized greater life extensions. However, even those who quit much later in life gained some benefits: among smokers who quit at age 65 years, men gained 1.4 to 2.0 years of life, and women gained 2.7 to 3.7 years.
Conclusions. Stopping smoking as early as possible is important, but cessation at any age provides meaningful life extensions. (Am J Public Health. 2002;92:990996)
| INTRODUCTION |
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Life extension associated with smoking cessation may be a more tangible means of representing the reduction of mortality risk associated with quitting at various ages, compared with reductions in the relative or cumulative risk of death. The objective of this article is to quantify, with US-specific data, the benefit to a smoker of stopping smoking earlier rather than later in terms of life expectancy relative to never smokers and continuing smokers. Such estimates are needed to provide a sounder scientific basis for public health messages and clinical advice given to smokers about the effect of smoking cessation earlier in life on life expectancy. Furthermore, such messages need to be as simple as possible to have maximal effect.
Our goals were to identify the life-years that could be saved by stopping smoking at various ages and to determine whether even elderly smokers could reap benefits in terms of life years saved from smoking cessation. We used data from the Cancer Prevention Study II to construct a mortality-prediction model that included detailed information on smoking status and other potential confounding variables.4,5 We used relative risk of death by smoking category to predict mortality among 35-year-old Americans in 1990 under differing scenarios of age at smoking cessation. We compared life expectancy under the various cessation scenarios with life expectancy for persons aged 35 years in 1990 who had never smoked and for those who continued to smoke.
A major benefit of our study in comparison with past work was its use of the Cancer Prevention Study II to obtain relative risks of smoking. The Cancer Prevention Study II sample was large enough (> 10 million life-years of follow-up) to allow detailed modeling of the effect on mortality both of smoking duration and of age at smoking cessation; such controls would not be possible with a smaller database because of small-cell problems. Furthermore, the Cancer Prevention Study II database is somewhat more nationally representative than the Framingham Heart Study database,7 and in contrast to the British Doctors Study database,8 it pertains to the United States and includes a much broader population than that study's single group of professional workers. These other databases are the leading alternatives from which one could obtain relative risk estimates. Finally, we projected mortality decreases after cessation with the 1990 census population and the relative risks obtained from the Cancer Prevention Study II, which provides a realistic estimate of the benefits of smoking cessation on longevity in the American context and allowed us to compare our results with recent findings from Great Britain.6
| METHODS |
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Each participant completed a confidential, 4-page mailed questionnaire on smoking habits, alcohol intake, marital status, education, and other characteristics. We excluded participants who provided incomplete data on smoking habits or men who reported ever smoking a pipe or cigar (138 609 men and 72 459 women). We also excluded people who reported being sick at enrollment (34 824 men and 61 522 women), because they may have changed their smoking habits (by quitting smoking or smoking fewer cigarettes) as a result of their illness; their inclusion in the study most likely would have underestimated the mortality benefits of smoking cessation and would dilute the public health message that our article develops regarding what smokers can expect by way of life extension if they quit smoking at a given age. Analyses were based on the remaining 877 243 participants (334 918 men and 542 325 women).
Deaths occurring between date of enrollment and December 31, 1996, were ascertained through personal inquiries from American Cancer Society volunteers in September 1984, 1986, and 1988 and through automated linkage to the National Death Index in December 1989, 1991, 1994, and 1996.13 By the end of 1996, 20% of the original respondents had died, and follow-up for 0.2% had been truncated in September 1988 because of insufficient data to link to the National Death Index. We obtained death certificates or multiple cause-of-death codes for 98.6% of all deaths. The underlying cause of death was coded according to the International Classification of Diseases, 9th Revision.14 Our analysis included 149 351 deaths from all causes. Person-years at risk were accrued from month of enrollment through the last date in the study: the end of follow-up (December 31, 1996), date of death, or date lost to follow-up (because of insufficient information for National Death Index linkage), whichever occurred first. This resulted in 7.2 million female person-years and 4.3 million male person-years.
Deaths from all causes were identified from 1982 through December 31, 1996.
Estimation Strategy With Cancer Prevention Study II Data
We estimated the relative risk of death by smoking status, age, and sex using a Cox proportional hazards model, which was implemented using multiple logistic regression estimated by maximum likelihood methods.15 Age was controlled for in 1-year increments, with age younger than 40 years truncated at 40 and age older than 90 years truncated at 90. Models were estimated separately for men and women and for persons younger than age 70 years and those 70 years or older. Smoking status at the baseline survey was initially assumed to remain constant throughout the study period.
Current smokers were stratified by 10-year age increments: younger than 50, 50 to 59, 60 to 69, 70 to 79, and 80 years or older. Former smokers were stratified by 10-year age increments (as for current smokers) and years of cessation (cigarette abstinence: for 3 to 5, 6 to 10, 11 to 15, and 16 years or more). Those who had quit less than 3 years before baseline were combined with current smokers in the analyses because they have similar mortality rates and because relapse among recent quitters is high.4 Age and number of years as a former smoker were treated as time-dependent covariates and were advanced for each year in the study. For example, smokers who quit in 1978 and who were alive in 1983 were considered former smokers, 3 to 5 years after cessation, in 1983. The following year, the same people would be categorized with former smokers, 6 to 10 years after cessation.
Alcohol consumption was categorized into 5 groups: teetotalers, up to 2 drinks per day, 3 to 4 drinks per day, 5 or more drinks per day, and missing information on drinking. Education had 4 categories: less than high school, high school graduate, some college, and college graduate or more. Other variables were race (non-White vs White), marital status (married vs not), and self-reported history of cancer. All covariates other than age were modeled as dummy variables using the categories shown in Table 1
(see Table 3
note).
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We subsequently conducted sensitivity analyses to estimate the extent to which changes in smoking status would cause underestimation of the true risk in continuing smokers. For this estimation, we used follow-up information on smoking status, which was available in 1992 for a fraction of the cohort.12 Among participants in the 1992 survey who had been current smokers in 1982, 56.8% of the men and 52.7% of the women were no longer smoking, whereas 3.0% of the male and female former smokers had relapsed. The subsample (n = 184 194) that participated in the 1992 survey was a selfselected group that was more highly educated, was older, and included a higher proportion of White persons compared with the baseline Cancer Prevention Study II cohort.12 Smoking prevalence also was lower in the 1992 subsample (7% vs 20%).
We computed annual rates of cessation and relapse by age and sex. For example, among men who were aged 55 years in 1982, the annual cessation rate was 0.0705, and the annual relapse rate was 0.0042. We calculated a "true" relative risk for current smoking, correcting for misclassification due to cessation among the current smokers over the follow-up period. Because the rate of relapse among former smokers was so low, we did not adjust for it in our calculations. We estimated the proportion of current smokers who quit for each year of follow-up. Next, we used these proportions and the observed person-years for current smokers to calculate the number of person-years contributed by each smoking group (e.g., continuing smokers, former smokers who had quit 35 years previously). Then, we constructed an equation in which the observed relative risk for current smoking equaled the average "true" relative risk for current smoking plus the observed relative risk for former smoking weighted by the person-years in each group. Solving for the "true" relative risk corrected for misclassification due to change in smoking status.
Estimation of Smoking-Specific Mortality Rates in the United States
US census vital statistics data allow stratification of all-cause death rates by age, race, and sex but not by smoking status. To estimate mortality by smoking status, we first calculated the relative risk of death from all causes for stratified age, race, sex, and smoking-status groups in the Cancer Prevention Study II. We then multiplied these relative risks by the observed mortality rate in the United States for the corresponding age, race, and sex group in 1990 and divided by a factor (representing the weighted average of the category-specific relative risks) to obtain estimated US mortality rates for each age, race, sex, and smoking-status group.
Projecting Mortality by Cessation Scenarios
We projected smoking-specific mortality rates in the 1990 census population of men and women who were aged 35 years in 199016 under alternative scenarios in which all smokers quit at a particular age (we used ages 35, 45, 55, and 65). For cessation at ages 45, 55, and 65 years, we used only those persons aged 35 years in 1990 who survived to ages 45, 55, and 65, respectively. Projected mortality under each scenario was compared with the projected mortality if all current smokers had continued to smoke (Table 2
). We also projected mortality among persons aged 35 years assuming that the smoking behavior rates (prevalence, initiation, cessation, relapse) for each stratified age, sex, and education group from the 1991 National Health Interview Survey and the National Health and Nutrition Examination Survey I held true, as well as assuming that no person aged 35 years in 1990 had ever smoked cigarettes.17,18
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| RESULTS |
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Current smokers had higher all-cause mortality compared with never smokers, regardless of their age or sex (Table 3
), and the relative risk of death rose with increasing age, peaking at age 50 to 59 years in men and age 60 to 69 years in women and then declining among older smokers (although absolute risk of death for older smokers remained high). The relative increase in death rates from all causes among smokers was 2.34 (95% confidence interval [CI] = 2.21, 2.48) in men younger than age 50 years; 2.82 (95% CI = 2.76, 2.88) for those aged 50 to 59 years; 2.80 (95% CI = 2.76, 2.84) for those aged 60 to 69 years; 2.52 (95% CI = 2.46, 2.58) for those aged 70 to 79 years; and 1.81 (95% CI = 1.75, 1.88) for men 80 years and older. A similar pattern of rising and then declining relative risk of death was observed for female smokers.
Death rates among former smokers who were older than age 50 years in 1982 were nearly always higher than the rates among never smokers, regardless of how long before 1982 they had quit smoking. For former smokers younger than age 50 years, the risk of death usually was not different from that of never smokers. Among former smokers, the relative risk of death by years since cessation in 1982 generally rose with increasing age up to age 70 to 79 years and then declined. Alternatively, given a particular age group in 1982, the relative risk of death decreased as the years since cessation increased, showing that cessation at earlier ages reduced mortality. The pattern for women was similar.
Annual death rates of men aged 50 to 59 years who had quit smoking 16 or more years before enrollment were 13% higher than those of never smokers (relative risk [RR] = 1.13; 95% CI = 1.05, 1.21), rates of those aged 60 to 69 years were 23% higher (RR = 1.23; 95% CI = 1.19, 1.27), rates of those aged 70 to 79 years were 32% higher (RR = 1.32; 95% CI = 1.29, 1.35), and rates of those aged 80 years and older were 19% higher (RR = 1.19; 95% CI = 1.15, 1.23). For women, relative risk of death among those who were long-term quitters (16 or more years since cessation) also remained elevated at ages 60 to 69 years (RR = 1.11; 95% CI = 1.06, 1.16), ages 70 to 79 years (RR = 1.20; 95% CI = 1.16, 1.24), and age 80 years and older (RR = 1.21; 95% CI = 1.17, 1.25). Although we did not directly control for the age at cessation, the intersection of the age and quit duration in 1982 clearly illustrates that smoking cessation at a younger age reduces mortality risk.
Estimation of Misclassification Bias Due to Change in Smoking Status
Correcting for cessation rates increased the relative risk for current smokers by 8% to 28%; the increase was higher in people aged 60 to 79 years. For example, the observed relative risk of death for current smoking among men aged 50 to 59 years in 1982 was 2.82; after correction, the relative risk was 3.11 (Table 4
). The adjustment for misclassification fixed the relative risk of death for male current smokers at greater than 3.0 and for female current smokers at greater than 2.5, except for the youngest and oldest age groups of both male and female current smokers.
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| DISCUSSION |
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Our estimate of life extension gained from stopping smoking at age 35 years was much larger than that found by Tsevat et al.22 They used relative risk information from the Framingham study conducted from the 1950s to the 1980s and found that smoking cessation at age 35 years would yield an average life extension of 0.5 to 1.2 years for men and of 0.4 to 0.8 years for women, relative to the life expectancy of persons aged 35 years who continued to show population-based smoking behavior, including some smokers who subsequently stopped smoking. We used a national and much larger sample and found a much higher benefit for smoking cessation at age 35 years than Tsevat and colleagues did: 3.3 to 3.9 additional years for men and 2.2 to 2.6 years for women with the same comparison groups that they used. They did not quantify life expectancy changes relative to a person aged 35 years continuing to smoke until death (which we highlighted in this article) or relative to persons who had never smoked; instead, they compared complete cessation with population-based quit rates.
Our estimate of the effect of never smoking was more similar to that found in the second half (19711991) of the British Doctors Study.23 Doll and colleagues determined that never smokers aged 35 years had a life expectancy that was 8 years longer than that of men aged 35 years who smoked until death (see Figure 6 from the Doll et al. study23), compared with about 8.910.5 years for men and 7.48.9 years for women in our study. Life extension between 1951 to 1971 and 1971 to 1991 increased by more than 3 years in the British Doctors Study. If the survival benefit of smoking cessation continues to increase over time as it did during the British Doctors Study, we likely underestimated the benefit of cessation for life extension, because our study period (19821996) was later and our follow-up period was shorter.
Several projection methods have been developed that allow simulation of the effects of changes in disease risk factors on mortality. Examples include the Coronary Heart Disease Policy Model,19 which used data from the Framingham study; the Canadian Population Health Model20; and the PREVENT21 model, developed initially in Holland. Recently, a dynamic model in the United States was developed that is mechanically similar to our model, although it was designed to project the prevalence of a risk factor (in the United States) and not its effect on mortality.24 The key difference between models of this type is how the relative risk of death by smoking status (or other risk factor) is determined. Improvements of our projection method relative to other projection methods include the following:
Our work had several limitations. First, we used mortality only as an end point. Smoking cessation also leads to compression of morbidity and improvement in quality of life.25 Second, we do not know whether the decline in baseline cardiovascular deaths will continue.26 Lung cancer death rates in lifelong nonsmokers were stable from the Cancer Prevention Study I (19591965) to the Cancer Prevention Study II (19821988), but this stability could disappear.5 Third, our analyses did not directly control for duration of smoking or age at quitting, even though we controlled for age directly, and the specification we used did control for age at cessation somewhat. The fact that the relative risk of death for current smokers rises and then falls with increasing age despite the fact that age is highly correlated with duration of smoking suggests that further stratification that directly accounts for these 2 determinants of lung cancer might improve estimates; however, such a specification would result in small-cell problems even with a database as large as that of the Cancer Prevention Study II. Finally, we did not estimate the economic savings from reduced sickness or otherwise associated with smoking cessation, another relevant area of benefit.
Our calculation of the benefits of smoking cessation in terms of life extension agrees with recent findings documented with data from the British populationsmoking cessation at any age reduces the risk of mortality, and cessation by age 35 years avoids essentially all of the excess risk of smoking.6 Our study differs from the British Doctors Study in that it focuses on the US population, illustrating that the significance of the British findings are not specific to Great Britain or to its smoking population. The major take-home message of that study was the decrease in cumulative risk of lung cancer death by age at cessation and the lung cancer mortality avoided, whereas our focus has been on overall life extension associated with smoking cessation at different ages. Although these 2 ways of documenting the benefit of smoking cessation are complementary, we believe that a focus on life extension is a more straightforward way of representing the benefits of smoking cessation to smokers.
| Acknowledgments |
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| Footnotes |
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Accepted for publication January 2, 2002.
| References |
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2. McGinnis JM, Foege WH. Actual causes of death in the United States. JAMA.1993;270:22072212.[Abstract]
3. Healthy People 2010: Understanding and Improving Health. Washington, DC: US Dept of Health and Human Services; 2001.
4. The Health Benefits of Smoking Cessation. Washington, DC: Center for Chronic Disease Prevention and Health Promotion, Office of Smoking and Health; 1990. DHHS publication CDC 90-8416.
5. Thun MJ, Heath CW Jr. Changes in mortality from smoking in two American Cancer Society prospective studies since 1959. Prev Med.1997;26:422426.[Medline]
6.
Peto R, Darby S, Deo H, Silcocks P, Whitley E, Doll R. Smoking, smoking cessation, and lung cancer in the UK since 1950: combination of national statistics with two case-control studies. BMJ.2000;321:323329.
7. Dawber TR. The Framingham Study: The Epidemiology of Atherosclerotic Disease. Cambridge, Mass: Harvard University Press; 1980.
8. Doll R, Gray R, Haffner B, Peto R. Mortality in relation to smoking: 22 years' observations on female British doctors. BMJ.1980;280:967971.
9. Garfinkel L. Selection, follow-up, and analysis in the American Cancer Society prospective studies. Natl Cancer Inst Monogr.1985;67:4952.
10. Stellman SD, Garfinkel L. Smoking habits and tar levels in a new American Cancer Society prospective study of 1.2 million men and women. J Natl Cancer Inst.1986;76:10571063.
11.
Thun MJ, Day-Lally CA, Calle EE, Flander WD, Heath CW. Excess mortality among cigarette smokers: changes in a 20-year interval. Am J Public Health.1995;85:12231230.
12.
Thun MJ, Calle EE, Rodriguez C, Wingo PA. Epidemiological research at the American Cancer Society. Cancer Epidemiol Biomarkers Prev.2000;9:861868.
13.
Calle EE, Terrel DD. Utility of the National Death Index for ascertainment of mortality among Cancer Prevention Study II participants. Am J Epidemiol.1993;137:235241.
14. Vital Statistics of the United States 1990. Hyattsville, Md: US Dept of Health and Human Services; 1994. Mortality Part A; vol II.
15. SAS/STAT Users Guide, Version 6. 4th ed., vol 2. Cary, NC: SAS Institute Inc; 1996.
16. 1990 Census of PopulationGeneral Population CharacteristicsUnited States. Washington, DC: Bureau of the Census, US Dept of Commerce; 1992.
17. McWhorter WP, Boyd GM, Mattson ME. Predictors of quitting smoking: the NHANES I follow-up experience. J Clin Epidemiol.1990;43:13991405.[Medline]
18. Garvey AJ, Bliss RE, Hitchcock JL, Heinold JW, Rosner B. Predictors of smoking relapse among self-quitters: a report from the Normative Aging Study. Addict Behav.1992;17:367377.[Medline]
19.
Weinstein MC, Coxson PG, Williams LW, et al. Forecasting coronary heart disease incidence, mortality, and cost: the Coronary Heart Disease Policy Model. Am J Public Health.1987;77:14171426.
20. Wolfson MC. POEHMa framework for understanding and modelling the health of human populations. World Health Stat Q.1994;47:157176.[Medline]
21. Gunning-Schepers LJ. The health benefits of prevention: a simulation approach. Health Policy.1989;12:1256.[Medline]
22.
Tsevat J, Weinstein MC, Williams LW, et al. Expected gains in life expectancy from various coronary heart disease risk factor modifications. Circulation.1991;83:11941201.
23.
Doll R, Peto R, Wheatley K, Gray R, Sutherland I. Mortality in relation to smoking: 40 years' observations on male British doctors. BMJ.1994;309:911918.
24.
Mendez D, Warner KE, Courant PN. Has smoking cessation ceased? Expected trends in the prevalence of smoking in the United States. Am J Epidemiol.1998;148:249258.
25.
Nusselder WJ, Looman CWN, Marang-van de Mheen PJ, van de Mheen H, Mackenbach JP. Smoking and the compression of morbidity. J Epidemiol Community Health.2000;54:566574.
26. Reducing the Health Consequences of Smoking: 25 Years of Progress. A Report of the Surgeon General 1989. Washington, DC: Center for Chronic Disease Prevention and Health Promotion, Office of Smoking and Health; 1989. DHHS publication CDC-89-8411.
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