Patients were eligible if they were 40 to 80 years of age , had COPD ( defined by a forced expiratory volume in 1 second [ FEV1 ] of less than 80 % and a ratio of FEV1 to forced vital capacity of less than 70 % ) , and had a smoking history of 10 or more pack-years , were receiving supplemental oxygen or treatment with glucocorticoids or antibiotic agents , or had had an emergency department visit or hospitalization for COPD within the past year .