Quitting ups risk of death among elderly smokers

Smoking is bad for health in all populations, but a recent study reports that quitting in late life is even more harmful, being associated with elevated risk of death especially among the oldest old people who have smoked for a long time.

The analysis included a cohort of 28,643 community-dwelling elderly adults aged ≥80 years (mean, 92.9 years) from the Chinese Longitudinal Healthy Longevity Survey. Cox proportional hazards models facilitated examination of the association between smoking cessation and risk of all-cause mortality.

During 136,585 person-years of follow-up, the incidence of all-cause mortality relative to never smokers was higher for current smokers (hazard ratio [HR], 1.06, 95 percent confidence interval [CI], 1.02–1.10), transient quitters (≤1 consecutive years since smoking cessation; HR, 1.23, 95 percent CI, 1.09–1.39), recent quitters (2–6 consecutive years since smoking cessation; HR, 1.22, 95 percent CI, 1.12–1.32), and long-term quitters (>6 consecutive years since smoking cessation; HR, 1.11, 95 percent CI, 1.02–1.22).

Cox models with penalized splines confirmed the associations, with an increased risk of all-cause mortality after smoking cessation. The highest risk of death was observed within 2–4 years after smoking cessation, with the risk gradually decreasing with duration of quitting.

Results were consistent in subgroup and sensitivity analyses, which were conducted to reduce the impact of reverse causation.