U.S. regulatory perspective on the minimal clinically important difference in chronic obstructive pulmonary disease.

This paper outlines the regulatory issues surrounding the determination and use of minimally clinically important differences (MCID) in assessing measures of outcomes from treatments of chronic obstructive pulmonary disease (COPD). To place this discussion in context, it is important to understand the current state of approved therapies for COPD, as well as newer directions in therapy. This paper discusses the currently available, approved drug therapies for COPD in the United States and how they were approved. This is followed by an overview on the use of MCID for assessing outcomes in therapies for COPD, as well the more general experience with MCID from the U.S. regulatory perspective.