Research Analysis · Everyday foundations
Stopping smoking was associated with lower mortality at every age studied
Two large observational analyses found substantially higher mortality with current cigarette smoking and lower excess mortality after stopping. The estimates describe populations; they are not an individual forecast and do not promise a particular person extra years.
Evidence scope
What these cohorts can—and cannot—show
- Population or model
- Adults age 20–79 represented in linked national cohorts in the United States, United Kingdom, Norway and Canada
- Design
- two large observational mortality analyses; smoking status and cessation history were self-reported
- Comparator
- current or former cigarette smoking compared with never smoking; cessation timing also compared with continued smoking
- Duration
- Jha linked interviews from 1997–2004 through 2006; Cho pooled cohorts spanning 1974–2018 with 15 years of follow-up
- Primary outcome
- all-cause and cause-specific mortality, plus modeled survival estimates
- Evidence maturity
- Human mortality · large observational cohorts
- Funding & conflicts
- Jha reported government and academic grant support. Cho was funded by CIHR FDN-154277; the publisher says disclosure forms were filed, but accessible primary metadata does not itemize them.
- Safety & status
- Cigarettes are highly addictive. These studies evaluated mortality associations, not the safety or effectiveness of a particular cessation method. No linked correction or retraction affecting the central results was identified at review.
Bottom line: Current cigarette smoking was associated with roughly three times the mortality of never smoking in both analyses. Stopping was associated with lower excess mortality at every age studied.
Not established: The analyses do not prove an exact causal effect for every subgroup, forecast an individual lifespan, or choose a cessation treatment.
Current smoking was associated with much higher mortality
Jha and colleagues followed 202,248 US adults age 25 or older. From ages 25 to 79, the adjusted mortality hazard ratio for current versus never smoking was 3.0 in women and 2.8 in men. Current smoking was associated with more than ten years shorter life expectancy. These are population-level associations, not an individual countdown.
Earlier cessation was associated with larger gains
Compared with continuing, stopping at ages 25–34, 35–44 and 45–54 was associated with about 10, 9 and 6 years longer life expectancy in the Jha models. Stopping before 40 was associated with about 90% less excess mortality. The study was observational, so these estimates can retain residual confounding and cannot promise anyone a particular number of years.
A later four-country analysis found the same direction
Cho and colleagues pooled 1.48 million adults and 122,697 deaths. Adjusted mortality hazard ratios for current versus never smoking were 2.8 in women and 2.7 in men; modeled survival from age 40 to 79 was 12 and 13 years shorter. Former-smoker estimates were lower than current-smoker estimates.
Associations appeared within years, then continued to narrow
In Cho, cessation for fewer than three years was already associated with lower excess mortality, including among adults older than 40. After ten or more years, survival estimates approached those of never smokers. “Associated” matters: this was not a randomized comparison of continuing versus stopping, and it did not compare cessation products or programs.
The evidence has important boundaries
Smoking histories were self-reported. Cohorts differed by country and era. Statistical adjustment cannot remove every difference between people who continue, stop or never smoke. The papers concern cigarette smoking and mortality; they do not establish the effects of every nicotine product, the best quitting method, or an individualized treatment plan.
If you want help stopping, a clinician or an established quit-support service can help you consider options that fit your health and circumstances. This article does not select a medication or plan.
Sources and editorial method
Three research passes were completed before prose. Every substantive statement maps to S73-01 through S73-08 in the frozen evidence record. See issue #155.
- Jha et al. (PMID 23343063)
- Jha DOI 10.1056/NEJMsa1211128
- Cho et al. (PMID 38329816)
- Cho DOI 10.1056/EVIDoa2300272
AI disclosure: AI-assisted research and drafting were used after the evidence review was frozen. Primary identities, claims, funding, limitations and source status were checked against the evidence map. This article is educational and not medical advice.
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Publication history
Published August 27, 2026 after three documented research passes, claim-level review and primary-identifier verification.