Smoking vs other risk factors as the cause of smoking-attributable deaths: confounding in the courtroom.

CONTEXT: The surgeon general estimates that more than 400,000 deaths are attributable to smoking annually in the United States. The tobacco industry has criticized the surgeon general's estimates because they do not control for the lower educational and socioeconomic status of modern-day smokers. OBJECTIVE: To determine whether controlling for education, occupation, race, alcohol consumption, and various dietary factors, in addition to age and sex, substantially alters the relative and attributable risk estimates associated with tobacco smoking. DESIGN, SETTING, AND PARTICIPANTS: Nationwide American Cancer Society prospective cohort study of 974, 150 US adults aged 30 years or older, enrolled in 1982 and followed up through 1988. (The same study is used for the surgeon general and Centers for Disease Control and Prevention [CDC] estimates of smoking-attributable deaths in the United States.) MAIN OUTCOME MEASURES: Death from each of the chronic diseases considered in the CDC's estimate of smoking-attributable mortality (cancers of the lung, oropharynx, larynx, esophagus, pancreas, kidney, bladder, and cervix; ischemic heart disease, arterial disease, and other heart conditions; stroke; chronic obstructive pulmonary disease; and other respiratory conditions). Estimates adjusted for multiple covariates were compared with those adjusted for age only among current and former vs never smokers. RESULTS: Adjusting for multiple covariates slightly decreased the relative and attributable risk estimates for current smoking in both men and women, but slightly increased the estimates for former smoking in women. Multivariate adjustment decreased the overall estimate of deaths attributable to smoking in the United States by approximately 1%, from 401,109 to 396,741 per year. CONCLUSIONS: Our study suggests that federal estimates of deaths caused by smoking are not substantially altered by adjustment for behavioral and demographic factors associated with smoking beyond the current adjustment for age and sex. JAMA. 2000;284:706-712

Cigar smoking and death from coronary heart disease in a prospective study of US men.

CONTEXT: The prevalence of cigar smoking has increased rapidly in the United States since 1993. Although cigarette smoking is known to be an important cause of coronary heart disease (CHD) mortality, the relationship between cigar smoking and CHD mortality is unclear. OBJECTIVE: To determine whether cigar smoking increases risk of CHD mortality. DESIGN: Prospective cohort study with follow-up for mortality from 1982 through 1991. SETTING: United States. PARTICIPANTS: A total of 121 278 men, aged 30 years and older, in the American Cancer Society's nationwide Cancer Prevention Study II cohort who completed a baseline questionnaire on smoking history and other risk factors in 1982, had never smoked cigarettes or pipes, and had no diagnosed heart disease or diabetes at baseline. MAIN OUTCOME MEASURE: Death from CHD recorded as the underlying cause of death on the death certificate. RESULTS: There were 2508 deaths from CHD from 1982 through 1991. The association between cigar smoking and death from CHD was stronger among younger men and current rather than former smokers, as is observed with cigarette smoking. No increased risk was observed among current cigar smokers aged 75 years or older, or for former cigar smokers of any age. For men younger than 75 years who were current cigar smokers at baseline, the adjusted rate ratio for CHD mortality was 1.30 (95% confidence interval, 1.05-1.62). CONCLUSIONS: These results suggest that smoking cigars increases risk of early death from CHD. Any adverse effect of cigars on CHD is of particular importance given the rapidly rising prevalence of cigar smoking in the United States.