1153 / 1983
• 5887 patients with asymptomatic airway obstruction
•
intervention + inhaled bronchodilator
•
intervention + inhaled placebo
•
usual care
Anthonisen Ann Intern Med 2005
% smokers @ 5yr intervention usual care p
none
22
5
intermittent
29
23 <.001
permanent
49
71
NTT = 100/17 = 6