Risk factors for COPD exacerbations in inhaled medication users: the COPDGene study biannual longitudinal follow-up prospective cohort.
Busch R, Han MK, Bowler RP, Dransfield MT, Wells JM, Regan EA, Hersh CP. Risk factors for COPD exacerbations in inhaled medication users: the COPDGene study biannual longitudinal follow-up prospective cohort. BMC Pulm Med. 2016 Feb 10; 16:28.