This was a multi-centre, randomised, double-blind, placebo-controlled study. The duration of subject participation was 48 weeks. There was an initial screening period of up to 2 weeks. The first screening visit consisted of medical history, clinical assessment, safety laboratory assessments and complete pulmonary function testing. The screening period was followed by a randomised treatment period where patients received tiotropium (Spiriva) or placebo in a ratio of 2:1. During the treatment period there were a total of 5 clinic visits (including randomisation and EOT visit). Each visit included lung function measurements and clinical assessments (SQRQ, COPD Symptom scores, physician's global assessment, COPD exacerbations/hospitalisations, vital signs and rescue medication use) in addition to adverse event reporting. The final visit consisted of a telephone contact 2 weeks after the patient completed their trial medication.