Using forced vital capacity (FVC) in the clinic to monitor patients with idiopathic pulmonary fibrosis (IPF): pros and cons.

Nathan, Steven D; Wanger, Jack; Zibrak, Joseph D; Wencel, Mark L; Burg, Cindy; Stauffer, John L

INTRODUCTION Forced vital capacity (FVC) decline is predictive of mortality in patients with idiopathic pulmonary fibrosis (IPF) and has been used as a clinical trial endpoint to define disease progression. How to interpret FVC findings in an individual patient with IPF in the real-world setting amid uncertainty about the measurement accuracy and variability has not been well established. AREAS COVERED This review highlights the challenges and limitations of using FVC in the clinic to monitor disease progression in patients with IPF. Spirometry is noninvasive, relatively simple, and inexpensive. FVC measurements provide evidence for trends over time in patients with IPF. When using FVC in the clinic, several important challenges and limitations, including visit-to-visit variability, dependence on patient effort, inconsistent quality control, limitations on accuracy, and the influence of comorbidities and pretest factors, must be considered. Recent studies suggest the potential for home spirometry devices to facilitate more frequent collection of data and perhaps demonstrate more accurate trends. EXPERT OPINION Measuring FVC decline in the clinic has an important role in monitoring disease progression in patients with IPF, but additional measures of disease progression should be considered along with FVC to facilitate decision-making about disease management.