A lung function threshold for survival? - FEV1Q and mortality in patients with COPD and chronic respiratory failure
INTRODUCTION: The FEV1 quotient (FEV1Q), calculated as the index between FEV1 and a theoretical lower survivable FEV1 threshold of 0.4L for females and 0.5L for males, has been investigated as a novel method of interpreting results from lung function testing. The applicability of the FEV1Q in populations with chronic respiratory failure has not been studied, and the continuous association between
