The mortality risk from liver cirrhosis, after the data were adjusted to account for alcohol consumption, was more than three times higher in smokers than in nonsmokers. Even smokers who did not drink alcohol were at significantly increased risk of cirrhosis, compared with nonsmokers.
The risk of death due to infection was 2.3 times higher in smokers than in nonsmokers. This strong association was dose-dependent, as infection-related mortality rose with increasing smoking intensity. And among study participants who had quit smoking, infection-related mortality declined as the number of years since cessation increased.
The rate of death due to renal failure was twice as high among smokers as among nonsmokers. And the rate of death due to hypertensive heart disease, the only category of heart disease not already established as smoking related, was 2.4 times higher in smokers. The latter association “is relevant for assessing the public health burden of smoking, since a considerable number of deaths in the United States are attributable to hypertensive heart disease,” according to Mr. Carter and his associates.
Smoking also was strongly associated with “multiple diseases too uncommon to examine individually.” This included all rare cancers combined, rare digestive diseases, and respiratory diseases other than those already known to stem from smoking.
In women, smoking raised breast cancer mortality, with a relative risk of 1.3. This association was strongly dose dependent. In men, smoking raised prostate cancer mortality, with a relative risk of 1.4.
This study was limited in that most of the participants were white and better educated than the general population, which may affect the applicability of the results to other populations.