Smoking After 70 Increases Risk of Death
Smoking continues to be a leading modifiable cause of cancer and premature mortality. A recent study suggests that smoking over the age of 70 is associated with being three times more likely to die than those who have never smoked, and that former smokers were less likely to die the sooner they quit smoking.
Participants in the study included more than 160,000 people age 70 and older who took part in the NIH-AARP Diet and Health Study. In 2004-2005, all of the participants completed a questionnaire that included their smoking use. It asked how many cigarettes per day people smoked and their smoking history throughout nine age periods. The researchers classified people who were still smoking in their 70s as “current smokers” and classified those who quit by the decade in which they quit.
The researchers tracked reported deaths until the end of 2011 and used the National Death Index to determine which deaths were associated with smoking. They then analyzed the data between 2014 and 2016 to examine if there was a correlation between when people started smoking, when they quit, and the amount they smoked after turning 70 and their age at death.
At the onset of the study, the median age of the participants was 75, 56% were former smokers, and 6% were current smokers. When the researchers broke it down by gender, 31% of the men had never smoked and 48% of the women had never smoked. Men smoked more than women, averaging 18.2 pack years versus 11.6 pack years. They were also more likely to have started smoking before 15 years of age (19%) than women (9.5%).
During the average 6.4 year follow-up period, 16% of the participants died: 12.1% of the people who never smoked and 16.2%, 19.7%, 23.9%, and 27.9% of former smokers who quit between ages 30-39, 40-49, 50-59, and 60-69 died, respectively. Current smokers had the highest death rate, with 33.1% dying. Mortality rates for women were lower than those for men.
Researchers from the National Cancer Institute conducted the study. It was published online ahead of print on November 30, 2016, in the American Journal of Preventive Medicine.