The Lung Health Study

Abstract

OBJECTIVE: To determine whether smoking intervention and use of an inhaled bronchodilator can slow the rate of decline in forced expiratory volume in 1 s (FEV₁) in smokers with mild obstructive pulmonary disease.DESIGN: Randomized clinical trial: participants randomized to one of three groups: smoking intervention plus inhaled bronchodilator (Atrovent; ipratropium bromide) (SIA): smoking intervention plus placebo (SIP); or no intervention (usual care, UC).SETTING: Ten centres in the United States and Canada.PARTICIPANTS: A total of 5887 smokers, aged 35 to 60 years, with FEV₁ 55 to 90% predicted and FEV₁/forced vital capacity (FVC) less than 70%.INTERVENTIONS: Smoking intervention: intensive program combining behaviour modification and use or nicotine gum, with a subsequent maintenance program to prevent relapse. Bronchodilator: ipratropium bromide, two puffs three times daily from a metered dose inhaler.MAIN OUTCOME MEASURES: Change in FEV₁ over a five-year period.RESULTS: Sustained smoking cessation was achieved in 22% of both intervention groups (SIA, SIP), compared with 5% in UC. Both SIA and SIP groups showed significantly smaller declines in postbronchodilator FEV₁ over the five years of the study - 184 mL and 209 mL, respectively. compared with 267 mL in UC. This difference was accounted for by an increase in FEV₁ in the SIA (+39 mL) and SIP (+11 mL) groups in the first year of the study, compared with a decline in UC (-34 mL). Those who achieved sustained smoking cessation experienced the greatest benefit, evident for the five years of study. There was a small noncumulative benefit associated with use of the active bronchodilator, which disappeared after the bronchodilator was discontinued.CONCLUSIONS: An effective smoking intervention program significantly reduced decline in FEV₁ in smokers with mild airways obstruction. Use of an inhaled anticholinergic bronchodilator did not influence the long term decline of FEV₁.