Table 2—

Effects of smoking cessation on all-cause and chronic obstructive pulmonary disease (COPD) mortality

First author [ref.]StudySubjects nFollow-up# yrsMortality outcomeSummary effectComments
Clinically based
 Kanner 33USA140 Utah COPD Pts7–13All-cause+In a case–control design (sex- and age-matched Pop), 12-yr survival probabilities were 86, 79 and 64% in never-, ex- and current smokers, respectively
 Postma 34Groningen, NL129 severe COPD Pts18All-cause+Pts were stratified according to bronchodilator reversibility; relative survival was higher in both current- and ex-smokers with greater reversibility; within each stratum, mortality was lower in ex- than current smokers
 Anthonisen 12USA985 COPD Pts aged 53–68 yrs3All-cause0Overall mortality was 23% (no difference between current and ex-smokers)
 Hersh 36USA139 M severe COPD Pts aged <53 yrs8All-cause+Recent smoking status predicted mortality independently of the effects of lifetime smoking intensity; Pts who were ex-smokers at enrolment had better survival than smokers
 Anthonisen 17LHS (USA)5887 M/F smokers with early COPD (FEV1 55–90%) aged 35–60 yrs5CV?There were 149 deaths during the study, caused largely by lung cancer and CVD; smoking cessation was associated with significant reductions in fatal CVD and coronary artery disease (too few COPD deaths for analysis)
 Anthonisen 35USA5887 M/F smokers with early COPD (FEV1 55–90%) aged 35–60 yrs14.5All-cause/ respiratory+After 14.5 yrs of follow-up, 731 patients had died; all-cause/respiratory MR was significantly lower in the special intervention group than in the usual care group
Population-based
 Doll 56UK6194 F doctors22COPD+COPD MRs lower in ex- than current smokers (5.0 versus 10.5–32.0% (depending on amount smoked))
 Rogot 32USA∼200000 M US veterans16COPD- to +COPD MRs higher in ex- than current smokers until 10 yrs after smoking cessation; thereafter lower MRs in ex- than current smokers (5.2 versus 12.1%)
 Carstensen 39SE25129 M16COPD+COPD MRs lower in ex- than current smokers (1.8 versus 1.9–5.3% (depending on amount smoked))
 Marcus 41Honolulu Heart Program (USA)11136 Japanese–American M aged 45– 65 yrs at enrolment20COPD- to +Age-specific COPD MRs calculated at 5-yr intervals (1965–1984); after 10 yrs, MRs were higher in ex- than never- and current smokers; after ≥15 yrs, MRs were similar in never- and ex-smokers and lower than current smokers
 Tockman 42USA36110 M/F aged 35–84 yrs from private census Pop, examined in two 6-yr periods884 M with FEV1 measures(subset of above)All-cause/ COPD+M MRs due to both all causes and COPD were greater in ex- than never-smokers, but lower than MRs for current smokers (p<0.05); this applied to both time periods; same trend for F, but too few COPD deaths in ex-smokers for analysis. Normal FEV1: OR 1 (never-smokers), 1.75 (ex-smokers), 4.80 (current smokers); FEV1 <65% pred: OR 3.71 (never-smokers), 6.50 (ex-smokers), 17.80 (current smokers)
 Kuller 40USA12866 M from MRFIT10All-cause+Lower all-cause MR in ex- than current smokers
 Lange 45DK14214 M/F from CCHS13COPD+Compared to never-smokers, RR of COPD mortality in F ex-smokers was 11 (95% CI 2.5–53), current smokers 15 (95% CI 3.1–65); RR in M ex-smokers was 3.0 (95% CI 0.9–10), current smokers 6.4 (95% CI 2.0–20)
 Tverdal 43NO68000 M/F aged 35–49 yrs13 (mean)All-cause+MRs for ex-smokers were intermediate to rates for never-smokers and smokers in both M and F
 Ben-Shlomo 38UK19018 M from Whitehall Study18COPD+Annual COPD MRs in never-, ex- and current smokers were 0.68, 0.95 and 2.2 per thousand study population
 Sunyer 44ES477 M from Barcelona aged >65 yrs8COPD0There were similar prevalences of self-reported respiratory illness in ex- and current smokers, and similar annual COPD MRs (6.0 versus 1.7 per thousand study population in never-smokers)
 Knuiman 48AU4277 M/F from the Busselton Health Study20–26All-cause-Per 10% decrease in FEV1, HR of all-cause mortality was 1.195 (95% CI 1.124–1.271) in ex-smokers and 1.167 (95% CI 1.108–1.229) in current smokers compared to never-smokers
 Engstrom 49SE291 smoking M born 191414CV0CV MRs in current- and ex-smokers similar by FEV1 decline tertile
 Pelkonen 46FI1582 middle-aged M30All-cause/ COPD+/-Compared to current smokers, there was lower total mortality in never- smokers, long-term ex-smokers and quitters; RR of COPD mortality in ex-smokers was 2.51 (95% CI 0.65–9.70) compared to current smokers.
 Godtfredsen 47DK19732 M/F from 3 Copenhagen Pop studies15.5 (mean)All-cause/COPD+/0RR of COPD mortality after smoking cessation was 0.77 (95% CI 0.44–1.35) compared to current smokers; HR of all-cause mortality was 0.65 (95% CI 0.56–0.74); no comparison was made with never-smokers
 Mannino 50USA5542 M/F aged 25–74 yrs from NHANES22All-cause+HR of all-cause mortality in a multivariate adjusted model was 1.1 in ex-smokers (95% CI 0.9–1.4), 1.4 in current smokers (95% CI 1.2–1.7)
 Doll 37, 55UK34439 M UK doctors40, 50All-cause/ COPD+COPD MRs in ex-smokers were intermediate between those of never-smokers and current smokers; RR of all-cause mortality lower in ex- than current smokers (1.3 versus 2.2)
Chinese
 Ho 51HK2030 M/F aged ≥70 yrs3All-cause/COPD0/-Similar all-cause MRs in ex- and current smokers; higher rate of respiratory mortality in F ex-smokers (RR 2.3 (95% CI 1.3–4.0))
 Lam 53HK1268 retired male cadres aged ≥60 yrs12COPD-RR of COPD mortality 2.13 (95% CI 0.55–8.30) in current smokers; 4.10 (95% CI 1.18–14.28) in ex-smokers
 Hsu 52TW4049 M/F aged ≥60 yrs7All-cause/ COPD0No differences between ex- and current smokers for all-cause or cause-specific mortality; this study does not meet standard quality criteria
 Lam 54HK56167 M/F aged ≥65 yrs4 (mean)All-cause/ COPD+/-RR of all-cause mortality in ex-smokers was 1.39 (95% CI 1.23–1.56) in M and 1.43 (95% CI 1.25–1.64) in F; rates were significantly higher in current smokers; COPD MRs were higher in ex- than current smokers
  • NL: the Netherlands; LHS: Lung Health Study; SE: Sweden; DK: Denmark; NO: Norway; ES: Spain; AU: Australia; FI: Finland; HK: Hong Kong; TW: Taiwan; Pt: patient; M: male; F: female; FEV1: forced expiratory volume in one second; Pop: population; MRFIT: Multiple Risk Factor Intervention Trial; CCHS: Copenhagen City Heart Study; NHANES: National Health and Nutrition Examination Survey; CV: cardiovascular; CVD: cardiovascular disease; MR: mortality rate; OR: odds ratio; % pred: % predicted; RR: relative risk; CI: confidence interval; HR: hazard ratio; +: risks lower in ex-smokers than smokers (benefits of quitting); -: risks higher in ex-smokers than smokers; 0: risks similar in ex-smokers and smokers; ?: results not clear. #: after smoking cessation; : RR and HR of never-smokers (reference group) = 1.0.