Smoking and All-Cause Mortality in Older People Systematic Review and Meta-analysis

Background: Smoking is an established risk factor of premature death. However, most pertinent studies primarily relied on middle-aged adults. We performed a systematic review and meta-analysis of the empirical evidence on the association of smoking with all-cause mortality in people 60 years and older. Methods: A systematic literature search was conducted in multiple databases including MEDLINE, EMBASE, and ISI Web of Knowledge and complemented by cross-referencing to identify cohort studies published before July 2011. Core items of identified studies were independently extracted by 2 reviewers, and results were summarized by standard methods of meta-analysis. Results: We identified 17 studies from 7 countries. Current smoking was associated with increased all-cause mortality in all studies. Relative mortality (RM) compared with never smokers ranged from 1.2 to 3.4 across studies and was 1.83 (95% CI, 1.65-2.03) in the meta-analysis. A decrease of RM of current smokers with increasing age was observed, but mortality remained increased up to the highest ages. Furthermore, a dose-response relationship of the amount of smoked cigarettes and premature death was observed. Former smokers likewise had an increased mortality (meta-analysis: RM, 1.34; 95% CI, 1.28-1.40), but excess mortality compared with never smokers clearly decreased with duration of cessation. Benefits of smoking cessation were evident in all age groups, including subjects 80 years and older. Conclusions: Smoking remains a strong risk factor for premature mortality also at older age. Smoking cessation is beneficial at any age.