Racial Disparities in Smoking-Attributable Mortality and Years of Potential Life Lost --- Missouri, 2003--2007

An estimated 443,000 deaths in the United States occur each year as a result of cigarette smoking and exposure to secondhand smoke (1). These deaths cost the nation approximately $97 billion in lost productivity and $96 billion in health-care costs (1). During 2000--2004 in Missouri, smoking caused 9,600 deaths, 132,000 years of potential life lost (YPLL), $2.4 billion in productivity losses, and $2.2 billion in smoking-related health-care expenditures annually (2). To limit the adverse health consequences of tobacco use, states implement comprehensive tobacco control programs that identify disparities among population groups and target those disproportionately affected by tobacco use (3). This report compares the public health burden of smoking among whites and blacks in Missouri by estimating the number of smoking-attributable deaths and YPLL in these population subgroups during 2003--2007. The findings indicate that the average annual smoking-attributable mortality (SAM) rate in the state was 18% higher for blacks (338 deaths per 100,000) than for whites (286 deaths per 100,000). The relative difference in smoking-attributable mortality rates between blacks and whites was larger for men (28%) than women (11%). For Missouri, these estimates provide an important benchmark for measuring the success of tobacco control programs in decreasing the burden of smoking-related diseases in these populations and reaffirm the need for full implementation of the state's comprehensive tobacco control program (3).

The adult module of CDC's Smoking-Attributable Mortality, Morbidity, and Economic Costs (SAMMEC) system* was used to calculate the SAM and YPLL rates for 19 disease categories.† Five-year average annual SAM and YPLL rates were computed from annual reports generated through SAMMEC. These estimates only cover deaths among persons aged ≥35 years. Deaths attributable to secondhand smoke or from smoking-related fires were not included. Sex-, race-, and age-specific smoking-attributable deaths were calculated by multiplying the total number of deaths in each of the 19 disease categories by the estimate of the smoking-attributable fraction (SAF) of deaths for each demographic group.§ These deaths were then grouped into three cause-of-death categories (malignant neoplasm, circulatory disease, and respiratory disease). Both races were assumed to have the same relative risk for dying from a particular disease among the 19 disease categories attributable to smoking. Missouri data for 2003--2007 from the Behavioral Risk Factor Surveillance System (BRFSS) were used to estimate the age-, sex-, and race-specific annual prevalence of current and former smoking in the state.¶ Missouri death records for 2003--2007 were used to calculate the age-, sex-, race-, and disease-specific number of deaths each year (4). The life expectancy (average remaining years of life) by age group and sex was calculated using the abridged life table,** and absolute and relative disparity indexes were computed for each smoking-related disease category (Tables 1--3) comparing SAM rates for blacks to SAM rates for whites. T-tests were used to evaluate the statistical significance (p≤0.05) of differences in SAM/YPLL rates between blacks and whites for the three major disease categories and major diseases.††

During 2003--2007, smoking caused an estimated average of 9,377 deaths (8,400 among whites and 853 among blacks§§) annually among adults in Missouri (Table 1). An estimated 18.1% of deaths among persons aged ≥35 years in Missouri were the result of cigarette smoking (total number of deaths for this age group was 51,856). Smoking caused 32.1% of all deaths from cancer, 15.3% of all circulatory deaths, and 46.5% of all respiratory deaths in Missouri during this period (4). In the cancer category, the major cause of death was cancer of the trachea, lung, or bronchus; in the circulatory category, the major cause was ischemic heart disease; and in the respiratory disease category, the major cause was chronic airway obstruction (Table 1). For both blacks and whites in Missouri, regardless of sex, the leading cause of SAM was cancer, followed by circulatory and respiratory diseases.

Although SAM for blacks represented only 9.1% of the total SAM, the SAM rate for blacks in Missouri was 18% higher than for whites (Table 2). This disparity was larger (28%) for black men than for black women (11%). SAM rates for blacks were 26% higher than for whites for malignant neoplasm and 53% higher for circulatory diseases but 32% lower for respiratory diseases.

The smoking-attributable YPLL rate for blacks also was 18% higher than for whites and differed most for men. Black men had a YPLL rate 25% higher than white men, and the rate for black women was 15% higher than for white women (Table 3). Similar to the SAM results, the YPLL rates for the three major disease categories showed that the YPLL rates for blacks were higher than for whites for malignant neoplasm and circulatory diseases but lower for respiratory diseases. The YPLL rate resulting from smoking-related cancer deaths for blacks was 19% higher than for whites, but 26% higher for the SAM rate. For circulatory deaths, the YPLL rate for blacks was 54% higher, similar to the disparity in the SAM rate (53%). For respiratory diseases, the YPLL rate for blacks was 33% lower than for whites, and similarly, 32% lower for the SAM rate. For specific diseases, blacks had a 14% higher YPLL rate for lung cancer, 35% higher rate for ischemic heart disease, and 38% lower rate for chronic airway obstruction than whites.

Reported by

N Kayani, PhD, SG Homan, PhD, S Yun, MD, PhD, Missouri Dept of Health and Senior Svcs. A Malarcher, PhD, Office on Smoking and Health, CDC.

Editorial Note

This is the first study to provide data on racial disparities in SAM and YPLL using SAMMEC. These data are valuable for Missouri's tobacco control program for documenting and evaluating changes in tobacco-related racial disparities in the state. Additional studies are needed to explain why Missouri blacks are more likely to die from smoking-related cancers and circulatory diseases than whites, but less likely to die from smoking-related respiratory diseases.

Variations in smoking-related mortality exist across states and occur because of differences in population demographics and tobacco use. Differences in other tobacco-use--related behaviors, variations in tobacco control programs and policies, and tobacco industry marketing also exist (5). Racial and ethnic disparities in smoking-related morbidity and mortality also are associated with socioeconomic status, cigarette smoking patterns, and differences in biologic and genetic factors; for example, smoking initiation and cessation rates vary by race, as does nicotine metabolism and disease outcomes among cigarette smokers (6). Significant racial disparities in SAM existed in Missouri during 2003--2007, with an average of 52 per 100,000 more black adults dying each year from cigarette smoking than white adults, reflecting an 18% higher SAM rate among blacks than whites. Smoking-attributable YPLL also were 18% higher among blacks than whites.

SAM during 2003--2007 reflects smoking patterns of the past 40 years. Although the smoking prevalence among blacks and whites in Missouri fluctuated during the past 2 decades, blacks tended to have a higher smoking prevalence than whites. The amount and duration of smoking and brands or types of cigarettes used also could contribute to disparities (7,8). However, data on these types of smoking patterns were not captured in Missouri's tobacco use surveillance systems. More research is needed to explore the causes of these disparities.

Smoking prevalence declined by 26.3% among white adults and 25.8% among black adults in Missouri during 1995--2009. In 2009, the smoking prevalence was 27.1% among black adults and was 22.1% among white adults. Among youths, smoking prevalence in Missouri declined during 1995--2009, to 19.4% in whites and 15.7% in blacks.¶¶ During the entire period, smoking prevalence among black young adults (aged 18--24 years) remained lower than for white young adults, but the prevalence of smoking among persons aged 35--44 years of either race was similar. The late initiation of tobacco use among black youths and black young adults suggests that the current racial disparities in smoking-associated morbidity and mortality in Missouri might change in the future; continued surveillance of youth and young adult smoking is needed because of this later initiation of smoking among blacks. Continued implementation of effective population-based tobacco control interventions that discourage initiation and increase cessation among youths and adults also is needed to prevent smoking-related morbidity and mortality in the next several decades (3,8).

In 2006, the Missouri Comprehensive Tobacco Use Prevention Program identified disparities in tobacco use, and the state disparities work group created a strategic plan for addressing the identified disparities. The plan was incorporated into Missouri's 2006--2009 and 2010--2014 comprehensive tobacco control plans. The Missouri Comprehensive Tobacco Control Program supports the Missouri Tobacco Quitline to help smokers (especially low-income smokers) quit smoking, and hosts a website that can assist public health agencies in developing interventions to reduce the health impact of and disparities in tobacco use.*** The quitline will continue to play a role in reducing racial disparities in smoking and smoking-related morbidity and mortality in Missouri. An analysis of 2005--2009 Missouri quitline data showed that slightly higher percentages of black smokers than white smokers were calling the quitline; black smokers comprised 12.6% of all smokers, but the quitline received 14.0% of all calls from black smokers.

The findings of this report are subject to at least four limitations. First, SAMMEC uses estimates of current year's smoking to estimate SAM; however, current prevalence estimates do not adequately reflect smoking patterns in past decades when the smoking prevalence was higher. These estimates also do not account for deaths associated with cigar and pipe smoking, the use of smokeless tobacco, secondhand smoke, smoking-related fires, and deaths among persons aged <35 years. Second, SAM rates for groups other than blacks and whites in Missouri could not be estimated accurately because of the small numbers of deaths; however, 99.5% of deaths from the 19 disease categories considered in this report were among blacks and whites. Third, the same relative risks for dying from a particular disease among the 19 disease categories attributable to smoking for current and former smokers were used for blacks and for whites, although relative risk might be different between blacks and whites. Preferences for types and brands of cigarettes as well as smoking intensity and duration differ between white and blacks and might result in differing relative risks. Finally, relative risk was adjusted for the effects of age but not for other potential confounders. However, research suggests that education, alcohol use, and other confounders had negligible additional effects on SAM estimates for lung cancer, chronic obstructive pulmonary disease, ischemic heart disease, and cerebrovascular disease (9).

Effective population-wide interventions (e.g., increasing the price of tobacco products through excise tax and implementing smoke-free policies) appear to reach all segments of the population; however, targeted strategies might still be needed for certain high-risk groups (e.g., persons with lower socioeconomic status or educational attainment) to reduce disparities (3,10). Race-specific SAM measures and race-specific trends in youth and adult smoking prevalence can be used to document and assess progress in eliminating tobacco-related disparities within a state.

References

1. CDC. Smoking-attributable mortality, years of potential life lost, and productivity losses---United States, 2000--2004. MMWR 2008;57:1226--8.
2. Kayani N, Yun S, Zhu BP. The health and economic burden of smoking in Missouri, 2000--2004. Mo Med 2007;104:265--9.
3. CDC. Best practices for comprehensive tobacco control programs---2007. Atlanta, GA: US Department of Health and Human Services, CDC; 2007. Available at http://www.cy118119.com/tobacco/tobacco_control_programs/stateandcommunity/best_practices. Accessed November 18, 2010.
4. Missouri Department of Health and Senior Services. Missouri information for community assessment: death MICA (2003--2007). Jefferson City, MO: Missouri Department of Health and Senior Services; 2008. Available at http://www.dhss.mo.gov/DeathMICA/index.html. Accessed November 18, 2010.
5. Farrelly M, Pechacek T, Thomas K, Nelson D. The impact of tobacco control programs on adult smoking. Am J Public Health 2008;98:304--9.
6. National Institutes of Health State-of-the-Science Panel. National Institutes of Health State-of-the Science conference statement: tobacco use: prevention, cessation, and control. Ann Intern Med 2006;145:839--44.
7. CDC. Tobacco use among U.S. racial/ethnic minority groups---African Americans, American Indians and Alaska Natives, Asian Americans and Pacific Islanders, and Hispanics: a report of the Surgeon General. Atlanta, GA: US Department of Health and Human Services, CDC; 1998. Available at http://www.cy118119.com/tobacco/data_statistics/sgr/sgr_1998. Accessed November 18, 2010.
8. CDC. The health consequences of smoking: a report of the Surgeon General. Atlanta, GA: US Department of Health and Human Services, CDC; 2004. Available at http://www.cy118119.com/tobacco/data_statistics/sgr/2004/index.htm. Accessed November 18, 2010.
9. Thun MJ, Apicella LF, Henley SJ. Smoking vs other risk factors as the cause of smoking-attributable deaths confounding in the courtroom. JAMA 2000;284:706--12.
10. Fiore MC, Jaen CR, Baker TB, et al. Treating tobacco use and dependence; 2008 update. Clinical practice guideline. Rockville, MD: US Department of Health and Human Services, Public Health Service; 2008. Available at http://www.surgeongeneral.gov/tobacco/treating_tobacco_use08.pdf. Accesssed November 18, 2010.

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