Godtfredsen N, Lam T, Hansel T, Leon M, Gray N, Dresler C, Burns D, Prescott E, Vestbo
Eur Respir J. 2008;32( 4):844-53.
The evidence base for the benefit of quitting smoking as regards morbidity and mortality
outcomes in patients with moderate-to-severe chronic obstructive pulmonary disease
(COPD) is limited. The present article is a review of the existing literature. A systematic
literature search in medical databases was performed until March 2006, and subsequently
until September 1, 2007. The outcomes examined were COPD-related morbidity and mortality
(including all-cause mortality) in COPD patients in connection with smoking cessation.
A total of 21 and 27 published articles on morbidity and mortality, respectively,
were identified and reviewed. For both outcomes, only a few of the studies included
patients with severe COPD. Most of the studies reported a beneficial effect of smoking
cessation compared with continued smoking, whereas a few found no improvement. Methodological
problems, including small study sizes, poor data quality, possibility of reverse causality
and incomplete ascertainment of cause of death, limit interpretation of some of the
studies. The evidence as a whole supports the conclusion that, even in severe chronic
obstructive pulmonary disease, smoking cessation slows the accelerated rate of lung
function decline and improves survival compared with continued smoking.