Detection of upper airway obstruction with spirometry results and the flow-volume loop: a comparison of quantitative and visual inspection criteria.

Abstract

The prevalence of reported upper-airway obstruction was 7.5%. The quantitative criteria showed low sensitivity for detecting upper-airway obstruction but exceeded that of visual criteria. The aggregate criterion increased the sensitivity to 69.4%, which suggests the need for additional criteria to help predict upper-airway obstruction.