A 4-Year Trial of Tiotropium in Chronic Obstructive Pulmonary Disease

Previous studies showing that tiotropium improves multiple end points in patients with chronic obstructive pulmonary disease (COPD) led us to examine the long-term effects of tiotropium therapy.

In this randomized, double-blind trial, we compared 4 years of therapy with either tiotropium or placebo in patients with COPD who were permitted to use all respiratory medications except inhaled anticholinergic drugs. The patients were at least 40 years of age, with a forced expiratory volume in 1 second (FEV(1)) of 70% or less after bronchodilation and a ratio of FEV(1) to forced vital capacity (FVC) of 70% or less. Coprimary end points were the rate of decline in the mean FEV(1) before and after bronchodilation beginning on day 30. Secondary end points included measures of FVC, changes in response on St. George's Respiratory Questionnaire (SGRQ), exacerbations of COPD, and mortality.