For each disease, CDC attributes only a percentage of the deaths as being due to smoking, based on the best medical science. For example, for heart disease, CDC estimates that the proportion of deaths due to smoking is only 16 percent for persons age 65 and older. The authors also stress that other risk factors must be statistically controlled for if the impact of a single factor like smoking is to be reliably determined. We agree and conducted a careful analysis to examine that very issue. For example, heart disease has many risk factors and probably no study is based on a complete set of risk factors.
Smokers tend to eat poorer quality diets, drink more, get less exercise, etc.
The authors also claim that many of the deaths from tobacco are not premature deaths. However, studies that have followed smokers and nonsmokers for many years have found that smokers are three times more likely to die between the ages of 45 and 64 and two times more likely to die between the ages of 65 and 84 than those who have never smoked. Any other definition is so speculative as to be flaky. In 1989, the State of Oregon asked physicians to report on death certificates whether tobacco use contributed to the death. Between 1989 and 1996, physicians reported that tobacco contributed to 20 percent of Oregon deaths, the exact percentage of deaths attributed to smoking over the same time period using CDC's method.