Assessment of mid flow rate measurements in patients undergoing methacholine challenge.

The objective of this study is to assess the FEF(25-75) and FEF(25-75)/FVC in relation to the FEV1 in patients who have had a methacholine inhalation challenge study for a variety of clinical indications. The study is a retrospective review of methacholine challenge results at the university medical center. One hundred twenty-one consecutive patients who had a methacholine challenge performed for clinical indications were included in the study with no intervention.