Lung function decline before and after treatment of World Trade Center associated obstructive airways disease with inhaled corticosteroids and long-acting beta agonists.

WTC-exposed firefighters treated with ICS/LABA had improved FEV1 slope after initiation, particularly among those who started earlier. Treatment was, however, not associated with FEV1 -slope improvement if started after the median initiation date (1/14/2010), likely because onset of disease began before treatment initiation. Research on alternative treatments is needed for patients with greater than average FEV1 -decline who have not responded to ICS/LABA.