RT Journal
A1 Batty G, Shipley MJ, Kivimaki M, Smith G, West R
T1 Impact of smoking cessation advice on future smoking behavior, morbidity, and mortality: Up to 40 years of follow-up of the first randomized controlled trial of a general population sample
JF Archives of Internal Medicine
JO Archives of Internal Medicine
YR 2011
FD November 28
VO 171
IS 21
SP 1950
OP 1951
DO 10.1001/archinternmed.2011.543
UL http://dx.doi.org/10.1001/archinternmed.2011.543
AB 
While there is evidence from cohort studies that people who stop smoking have a longer life expectancy relative to their nonabstaining counterparts,1 interpretation of these observational data is often complicated by confounding. That is, the characteristics of people who quit could be different in relevant, unmeasured ways from those who do not. Extended follow-up of participants in a randomized controlled trial, which should circumvent this problem, is scarce and limited to samples whose members already had a smoking-related disease.2- 3 Ten-year4 and 20-year5 follow-ups of study members in the Whitehall Smoking Cessation Study—to our knowledge, the only trial of an apparently healthy population with future mortality ascertainment—found little apparent benefit for life expectancy despite a reduction in cough, phlegm production, and rate of pulmonary decline at the 3-year follow-up.6 We present herein the results for smoking behavior after 3 decades of follow-up and mortality risk after 4 decades. With most of the trial participants now deceased, this provides an unusual opportunity to compare the gain in life years with what would be predicted from cohort studies.