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

ABSTRACT

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.

KEYWORDS:

• Idiopathic pulmonary fibrosis
• interstitial lung disease
• forced vital capacity
• spirometry
• patient monitoring

Article highlights

• Although FVC is well established as a practical endpoint in IPF clinical trials as a measure of disease progression, FVC measurements are highly variable from visit to visit in individual patients in a real-world setting.

• Advantages of using FVC include its noninvasiveness, simplicity, relatively small expense, and ability to monitor long-term trends in lung function. However, the measurement is limited by its visit-to-visit variability, dependence on patient effort, inconsistent quality control, limited accuracy, and impact of patient comorbidities.

• Additional measures of disease progression, such as diffusing capacity for carbon monoxide (DLco) and 6-minute walk distance (6MWD), should be considered along with FVC to facilitate decision-making about disease management in patients with IPF.

Acknowledgments

Support for third-party writing assistance, furnished by Health Interactions, Inc., was provided by F. Hoffmann-La Roche Ltd.

Declaration of interest

SD Nathan was a member of the ASCEND study steering committee; has served on a scientific advisory board and received research funding from InterMune (a wholly owned subsidiary of Roche); has received research funding and served as a consultant for Boehringer Ingelheim, Gilead and Roche/Genentech and is on the speakers bureau for Roche/Genentech; and his institution has received research funding from Boehringer Ingelheim and Roche/Genentech. JD Wanger has served as a consultant for Genentech and Fibrogen. J Zibrak has served as a consultant for Boehringer Ingelheim and Roche/Genentech. ML Wencel has served as a consultant and is on the speakers bureau for Genentech, Inc. C Burg and JL Stauffer are employees of Genentech, Inc. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Additional information

Funding

This manuscript was sponsored by F. Hoffmann-La Roche Ltd and Genentech, Inc.