Smoking in Older Adults

Smoking is a major risk factor for multiple chronic diseases, including cardiovascular disease and cancer, as well as for mortality from the leading causes of death. It is one of the 10 leading risk factors for death and is responsible for an estimated 12% of male deaths and 6% of female deaths worldwide. If changes in smoking behavior are not achieved, there will be ~1 billion deaths from smoking in the 21st century, according to researchers.

Data on the impact of smoking among older adults are lacking. The majority of previous studies on the risks of mortality from smoking have been conducted among middle-age adults. Researchers recently conducted a systematic review and meta-analysis of studies designed to evaluate the impact of smoking on all-cause mortality in individuals ≥60 years of age, with an emphasis on the strength of the association by age, the impact of smoking cessation at an older age, and factors that might affect results of epidemiological studies on the impact of smoking in an older population. Results of the analysis were reported in Archives of Internal Medicine [2012;172(11):837-844].

The researchers searched multiple databases, including MEDLINE, EMBASE, and ISI Web of Knowledge. The systemic literature search identified cohort studies published prior to July 2011. The eligible studies reported on the association of smoking and all-cause mortality in adults ≥60 years of age. The key words searched were: smoking or tobacco or cigarette and aged or old or elderly and mortality or death or dead and cohort or longitudinal.

Inclusion criteria were studies that reported smoking status and examined all-cause mortality in people ≥60 years of age (the outcome of interest) in the general population in a longitudinal cohort study design. Exclusion criteria were studies that did not report separate results for older people or did not provide an estimate of a relative-effect measure (hazard ratio, odds ratio, or relative risk) for the comparison of current or former smokers with those who never smoked; studies that did not reflect random general population samples were also excluded. There were 17 studies included in the final review.

All studies found an association between smoking and all-cause mortality. Relative mortality (RM) compared with never smokers ranged from 1.2 to 3.4 across studies, with an outlier of 0.5 in men ≥90 years of age. For women, the point estimates of RM ranged from 1.2 to 2.5. Three studies reported combined mortality rates for men and women who were current smokers; the point estimates ranged from 1.4 to 3.0.

A meta-analysis of the 15 studies that compared mortality of current smokers to never smokers found an RM of 1.83 (95% confidence interval [CI], 1.65-2.03) for both sexes and all age groups combined. In sex-specific meta-analysis, the results were similar for men and women.

There was a decrease of RM of current smokers with increasing age; however, mortality risk remained increased up to the highest ages. In addition, there was a dose-response relationship of the amount of smoked cigarettes and premature death.

A meta-analysis of the 14 studies that reported hazard ratios for all-cause mortality for former smokers compared with never smokers found an RM of 1.34 (95% CI, 1.28-1.40) for both sexes and all age groups combined. The increase in mortality of former smokers compared with never smokers continued up to the highest ages, but decreased with the duration of cessation.

The benefits of smoking cessation were evident in all age groups, including individuals ≥80 years of age.

The researchers noted that, “Smoking is a strong risk factor of premature mortality at an older age…The longer the tine since smoking cessation, the lower the RM of older former smokers; this fact calls for effective smoking cessation programs that are likely to have major preventive effects even for smokers aged 60 years and older.”