preventive intervention is that the adverse health effects of smoking can be abruptly altered by quitting. The ex-smokers risk of coronary heart disease (CHD) 12 months following cessation is approximately that of the person who has never smoked.⁷ Cessation also slows the development of chronic obstructive pulmonary disease (COPD),¹¹ and Wolf has observed that ex-smokers quickly shed the excess risk of stroke that can be attributed to cigarette smoking.³¹ Reduction in lung cancer risk, however, is slower, and the ex-smoker will always have a risk for this disease between 1.5 and 2 times that enjoyed by those who have never smoked.⁷

The 1985 Health Interview Survey²⁶ reported that 30 percent of adults in the United States were current smokers. Although smoking rates were fairly uniform between the ages of 20 and 55, the rate dropped rapidly among the elderly. Those 55 to 64 years of age still maintained a smoking rate of 30.2 percent; of those 65 to 74 years of age the rate was only 21.5 percent, and over age 75 the rate dropped to 8.5 percent.

There are three possible explanations for these findings. First, the birth cohort for those currently over the age of 65 may have had a lower rate of initiating cigarette smoking during adolescence and adulthood (i.e., the ever-smoked rate is lower in these cohorts). Second, it is possible that there are increasing cessation rates among those over age 65. Finally, some of the decrease in smoking rates may be due to the decreased survivorship of smokers. What evidence there is indicates that all three factors may be operative. Secular trends certainly explain some of the lower smoking rates among older women because the habit did not become socially acceptable for women until about 40 years ago. Direct evidence indicates that cessation rates have been observed to increase with age,²⁹ thus confirming the intuitive concept that, because most cessation attempts are unsuccessful, the elderly who have lived longer will therefore have had more opportunities to achieve cessation of smoking. Smoking certainly shortens life expectancy for both sexes, thus selectively eliminating smokers, particularly men, from surviving into old age.

The answer to the question of whether the health effects of cigarette smoking are age specific is complex. There is no evidence for such effects, yet the duration of smoking is an important factor