The hazard of persistent cigarette smoking in later life.

Data derived from four major prospective epidemiological studies in the U.S. and Britain indicate that persistent cigarette smoking in later life carries an appreciable hazard. In two of these studies men aged over 65 years who smoked cigarettes had a significantly higher mortality from coronary heart disease than men who had ceased to smoke cigarettes, and in all four studies their overall mortality was significantly higher than that of ex-smokers. At 65-74 years the overall mortality of men still smoking cigarettes was higher by 24 percent or more than that of ex-smokers, and at 75-84 years it was higher by 12 to 18 percent. The absolute difference in overall mortality was 9 to 13/1000 per person-years in both age-groups. A comparison of data on men who had given up smoking at different ages suggests that while the benefit is greater if smoking is stopped earlier in life, men in their sixties and (especially in the case of heavy smokers) their early seventies may still increase their longevity by giving up smoking cigarettes.