Effects of Tiotropium on Exacerbations in Patients with COPD with Low or High Risk of Exacerbations: A Post-Hoc Analysis from the 4-Year UPLIFT® Trial

Effects of Tiotropium on Exacerbations in Patients with COPD with Low or High Risk of Exacerbations: A Post-Hoc Analysis from the 4-Year UPLIFT® Trial