General Morbidity And All-Cause Mortality - NCBI Bookshelf - NCBI

Introduction

Smoking has long been known to increase mortality. Pearl's 1938 paper in Science showed increased mortality in users of tobacco compared to nonusers, a finding that was replicated in the 1950s by the first wave of cohort studies initiated to investigate the risks of smoking (Figure 11.1) (Pearl 1938). Previous Surgeon General's reports have commented on the increased overall risk for dying in smokers and identified smoking as the leading cause of avoidable premature mortality. The mortality risk associated with smoking has changed over time, driven by the trends in patterns of smoking in the population, as discussed in Chapters 2, “Fifty Years of Change 1964–2014,” 4, “Advances in Knowledge of the Health Consequences of Smoking: From 1964–2014,” and 13, “Patterns of Tobacco Use Among U.S. Youth, Young Adults, and Adults.” Consequently, this chapter provides updated evidence on smoking and all-cause mortality, drawing on a pooled analysis of data from five cohorts that spans the period 2000–2010.

Figure 11.1

Survivorship lines of life tables for White males falling into three categories relative to the usage of tobacco as in Pearl, 1938. Source: Pearl 1938. Reprinted with permission from American Association for the Advancement of Science, © 1938. (more...)

Other chapters in this report have addressed the causation of specific diseases by smoking. For each of these diseases, there is excess mortality attributable to smoking that is potentially avoidable through tobacco control. All-cause mortality provides a measure of the excess mortality attributable to smoking that integrates across all of these causes, as well as capturing mortality that may come from still unidentified associations of smoking with disease and through indirect pathways, such as diminished immune function.

Beyond causing specific diseases and a wide range of other adverse health effects, smoking is also associated with generally poorer health, when smokers are compared with nonsmokers. This chapter also addresses the evidence supporting such general adverse effects, which are not captured by the evidence on the many specific diseases caused by smoking. The 2004 Surgeon General's report concluded that smoking caused diminished health status, referring to a general reduction of health as manifest, for example, by absenteeism from work and self-report (U.S. Department of Health and Human Services [USDHHS] 2004). One manifestation of the diminished health status of smokers is an increase in morbidity (i.e., illness), generally.

These general health effects of smoking contribute to increased absenteeism, loss of well-being, and have implications for health care and its costs. As a result of the specific disease burden from smoking and the diminished health status of smokers, their health care costs exceed those of nonsmokers. This chapter examines new evidence, since the 2004 report, on all-cause mortality and measures of general health status, assessing the ongoing impact of smoking on health.

Chapter 12, “Smoking-Attributable Morbidity, Mortality, and Economic Costs” discusses the relationship of smoking to several highly prevalent illnesses, and the implications these have on national health burdens. In 2003, the Centers for Disease Control and Prevention (CDC) estimated that for the year 2000, 8.6 million persons (95% confidence interval [CI], 6.9–10.5) in the United States had an estimated 12.7 million (95% CI, 10.8–15.0) serious medical conditions that were caused by smoking. The most prevalent conditions were chronic bronchitis and emphysema, which accounted for 73% of the serious medical conditions reported by smokers. As discussed in previous reports (USDHHS 2004, 2010) and in Chapter 7, “Respiratory Diseases,” smoking is a primary cause of respiratory diseases. In Chapter 8, “Cardiovascular Diseases,” the causal relationship between tobacco smoke from either smoking and/or exposure to secondhand smoke and cardiovascular disease is presented. Chapter 10, “Other Specific Outcomes” of this report reviews the evidence of a causal relationship between smoking and diabetes, as well as the impact that smoking has on immune function.