Prospective Evaluation of Exacerbations Associated with Suboptimal Peak Inspiratory Flow Among Stable Outpatients with COPD.

Over one-third of outpatients with stable moderate to very severe COPD had a suboptimal PIF against a medium low resistance DPI. The phenotype of suboptimal PIF was short stature, female, and Black. Suboptimal PIF status was associated with shorter time to moderate/severe COPD exacerbations compared with optimal PIF.