WEDNESDAY, June 13, 2012 (MedPage Today) — Giving up cigarettes has benefits even if it happens later in life.
That's one of the findings of a meta-analysis of 17 studies that looked at the risk of all-cause mortality in smokers 60 or older, according to Hermann Brenner, MD, and colleagues at the German Cancer Research Center in Heidelberg, Germany.
Regardless of age, the risk of dying in a given time frame from any cause is sharply increased in smokers compared with people who have never smoked, they reported in the June 11 issue of Archives of Internal Medicine.
But the increased risk decreases in people who quit, and that benefit is still present even after age 80, the researchers found.
A host of studies have found that the risk of all-cause mortality is higher in smokers but most have focused on people in middle age, and it has not been clear if there is any attenuation of risk as a person grows older, Brenner and colleagues noted.
Indeed, commented Tai Hing Lam, MD, of the University of Hong Kong in Pokfulam, Hong Kong, the studies have shown that the absolute risk is that smoking will kill one of every two smokers.
The key finding of the study by Brenner and colleagues, Lam argued in an accompanying comment article, is that the risks of smoking remain high even into old age, and the benefits of quitting are also high.
In 17 cohort studies that included men and women 60 and older, Brenner and colleagues found that point estimates of relative mortality for smokers compared with never smokers ranged from 1.3 to 3.4 for men and 1.2 to 2.5 for women.
A meta-analysis of the studies found the relative mortality compared with never smokers was 1.83 over all ages and both sexes, they reported.
The relative mortality fell slightly with age but remained substantial.
The decline with age is likely due to a "depletion of susceptibles" effect, in which smokers most likely to die of the habit have already done so, the researchers suggested.
Brenner and colleagues found a similar pattern in former smokers. Over all, the relative mortality compared with never smokers was 1.34, but it was 1.54 among people ages 60 through 69, 1.36 among those ages 70 through 79, and 1.27 in those 80 or older.
The difference between the relative mortality rates for former and current smokers amounted to a risk reduction of 28 percent for those who quit.
And a similar calculation for the different age groups suggested that even at 80 or older, those who quit have a 24 percent reduction in the risk of death compared with current smokers of that age.
The analysis had some limitations including the fact that the involved studies had varying follow-up periods and age ranges. Also, the age ranges did not always match the age ranges chosen for the age-specific meta-analyses.
But the findings emphasize the need for effective public health messages, Lam said. For public health information and education, the great death risk of 1 in 2 to 2 in 3 should be highlighted consistently and widely," he wrote.
But for many older smokers, that message is not getting through, Lam argued.
"Many older smokers misbelieve that they are too old to quit or too old to benefit from quitting," Lam said. "A simple, direct, strong, and evidence-based warning is needed."
For physicians, the message is also clear, Lam concluded: "If you have helped two smokers quit, you have saved (at least) one life."
Last Updated: 6/13/2012