Smokers and non-smokers alike for the most part are aware of the harmful effects of smoking. The most harmful of all those effects is that smoking kills. A scientific research report published in January 2013 is a convincing reminder of the fact that smoking kills. The study also showed that quitting smoking can add years of life regardless of the age when quitting occurs but the younger the quitting age the greater the number of years added.
The study report is in the January 24, 2013 edition of the New England Journal of Medicine. The study involved 216,917 adults throughout the United States. The time period of the study was from 1997 through 2004. Individuals who participated in the study filled out US National Health Interview Surveys. Researchers matched the results of those surveys with the National Death Index and death certificates of the 13,700 participants who died before the study ended.
The study assigned participants to one of three smoking categories. Those categories were smokers, former smokers, and never smoked. The former smoker category meant participants smoked at least 100 cigarettes in their adult life but had quit for at least five years up until the time of death if death occurred. The never smoked category meant participants smoked fewer than 100 cigarettes in their adult life. The smoker category meant they smoked during the study.
Researchers statistically analyzed 13,700 deaths which occurred during the study. During their analysis they made adjustments for other factors which influence death such as alcohol consumption, obesity, and ethnicity. Results showed conclusively that participants who smoked died at a rate triple that of the ones who did not smoke. It also showed that those who never smoked were approximately twice as likely to live to the age of 80 as those who smoked.
The study also showed that male participants between the ages of 25 and 79 who smoked lost an average of 12 years of life and that the female participants between those same ages who smoked lost an average of 11 years of life compared to the participants who had never smoked.
Adjusted statistical calculations showed that the estimated likelihood of surviving to the age of 80 years was 38% for the women in the study who smoked compared to 70% for the women who had never smoked. Those same calculations for men in the study were 26% for smokers and 61% for those who had never smoked.
The difference in the percent chance of survival to age 80 between smokers and non-smokers is the absolute death rate. Previous studies have similarly shown a tripling of the relative death rate of smokers compared to non-smokers and the loss of approximately 10 years of life on the average for smokers but this study is the first to show as large an absolute death rate for smokers.
As bleak as the picture regarding smoking and premature death is, the study provides some optimism in terms of the benefits of quitting smoking. It showed that smokers who quit between the ages of 25 and 34 years lived almost as long as the participants who had never smoked. In other words, they gained approximately 10 years of life. Individuals who quit between the ages of 35 and 44 years still died earlier compared to the individuals who never smoked, but gained approximately 8 years of life on the average. Participants who quit smoking between the ages of 35 and 54 and those who quit between the ages of 55 and 64 gained approximately 6 and 4 years of life respectively.
Despite the sober reality of the link between smoking and premature death which this study confirmed, the proof that quitting smoking prolongs life will encourage many to quit smoking.