The objective of the study was to evaluate the degree of improvement in lung function in patients with chronic obstructive pulmonary disease (COPD) after treatment with tiotropium inhalation capsules compared to salmeterol inhalation aerosol .

Inclusion criteria:

• Ability to sign a written Informed Consent Form consistent with International Conference of Harmonization-Good Clinical Practice (ICH-GCP) guidelines prior to participation in the trial (i.e., prior to any study procedures, including any pre-study washout of medications).
• Age of 40 years or older.
• Smoking history of ≥10 pack-years.
• A diagnosis of relatively stable chronic obstructive pulmonary disease with an Forced expiratory volume in one second (FEV1) ≤60% of predicted normal and FEV1 ≤70% of Forced vital capacity (FVC).
• Ability to perform technically acceptable pulmonary function tests, and ability to maintain records during the study period as required in the protocol.
• Ability to inhale medication from the HandiHaler® and from a metered dose inhaler.

Exclusion criteria:

• Clinically significant diseases other than Chronic obstructive pulmonary disease (COPD). A clinically significant disease was defined as a disease or condition which, in the opinion of the investigator, could have put the patient at risk because of participation in the study or may have influenced either the results of the study or the patient's ability to participate in the study.
• Known moderate or severe renal insufficiency.
• A recent history (i.e., six months or less) of myocardial infarction.
• Unstable or life-threatening cardiac arrhythmias, including newly diagnosed, clinically relevant arrhythmia on the electrocardiogram (ECG) performed on Visit 1. Unstable arrhythmias included arrhythmias that required an intervention (i.e., hospitalization, cardioversion, pacemaker placement, and automatic implantable cardiac defibrillator (AICD) placement) or a change in drug therapy during the year preceding study enrollment.
• Hospitalization for heart failure during the past three years.
• History of life-threatening pulmonary obstruction, or a history of cystic fibrosis or clinically evident bronchiectasis.
• Other exclusion criteria apply.