- Patients with stable moderate to severe COPD and a smoking history of at least 10 pack years were eligible for inclusion in the study. Patients with significant diseases other than COPD were excluded as were patients with a recent history of myocardial infarction, history of malignancy, unstable or life-threatening cardiac arrhythmia, narrow-angle glaucoma, asthma or other allergic conditions. Patients treated with cromolyn, nedocromil, oral beta-adrenergics or unstable doses of oral corticosteroids were ineligible for inclusion in the study as were patients who had received previous treatment with tiotropium.