Evidence on the Effects of Giving Up Cigarette Smoking

Abstract

Evidence from a large prospective study indicates that ill health is the principal factor which leads some cigarette smokers to give up the habit. Thus, recent ex-smokers, as a group, are weighted with persons in ill health. In consequence, the death rate of recent ex-smokers is higher than the death rate of men who continue to smoke. After a few years, this selective bias wears off and the death rate of ex-cigarette smokers declines to a level considerably below that of men who continue to smoke cigarettes. These findings are supported by evidence from histologic studies as well as evidence from epidemiological studies.