title: Prognostic value of forced expiratory volume in 1 second/forced vital capacity in idiopathic pulmonary fibrosis.
abstract: Emphysema on high-resolution computed tomography of the chest is the recent focus in the general practice in idiopathic pulmonary fibrosis (IPF). However, adequate attention has not been paid to obstructive disorder. Therefore, we retrospectively evaluated the association between the degree of airway obstruction and longevity in IPF subjects, with a hypothesis that lower forced expiratory volume in 1 second (FEV1)/forced vital capacity (FVC) has an impact on prognosis. One hundred and fourteen consecutive IPF subjects who had been diagnosed with IPF and had undergone evaluation including pulmonary function test from January 2008 to May 2013 were included in the study. The relationship between baseline data and survival was examined. FEV1/FVC was widely distributed, ranging from 48.6% to 100%. On both univariate and multivariate Cox's regression analyses, lower FEV1/FVC was significantly associated with better survival (hazard ratio of 1.07 and 1.04 and 95% confidential interval of 1.03-1.10 and 1.01-1.08, respectively). Even on analysis with backward selection, FEV1/FVC remained a significant prognostic factor. FEV1/FVC is widely distributed and negatively predicts survival in IPF. A FEV1/FVC should be assessed in "real-world" general practice. Also, the effect of smoking on the clinical course of IPF should be investigated further.
authors.affiliation: Department of Respiratory Medicine and Allergology, Faculty of Medicine, Kinki University, Onohigashi, Osakasayama, Osaka, Japan nishiyama_o@yahoo.co.jp.
authors.forename: Osamu
authors.initials: O
authors.lastname: Nishiyama
authors.affiliation: Department of Respiratory Medicine and Allergology, Faculty of Medicine, Kinki University, Onohigashi, Osakasayama, Osaka, Japan.
authors.forename: Ryo
authors.initials: R
authors.lastname: Yamazaki
authors.affiliation: Department of Respiratory Medicine and Allergology, Faculty of Medicine, Kinki University, Onohigashi, Osakasayama, Osaka, Japan.
authors.forename: Akiko
authors.initials: A
authors.lastname: Sano
authors.affiliation: Department of Respiratory Medicine and Allergology, Faculty of Medicine, Kinki University, Onohigashi, Osakasayama, Osaka, Japan.
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Yamagata
authors.affiliation: Department of Respiratory Medicine and Allergology, Faculty of Medicine, Kinki University, Onohigashi, Osakasayama, Osaka, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Sano
authors.affiliation: Department of Respiratory Medicine and Allergology, Faculty of Medicine, Kinki University, Onohigashi, Osakasayama, Osaka, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Iwanaga
authors.affiliation: Department of Respiratory Medicine and Allergology, Faculty of Medicine, Kinki University, Onohigashi, Osakasayama, Osaka, Japan.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Higashimoto
authors.affiliation: Department of Respiratory Medicine and Allergology, Faculty of Medicine, Kinki University, Onohigashi, Osakasayama, Osaka, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Kume
authors.affiliation: Department of Respiratory Medicine and Allergology, Faculty of Medicine, Kinki University, Onohigashi, Osakasayama, Osaka, Japan.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Tohda
mesh_terms: D005541:Forced Expiratory Volume; D006801:Humans; D011379:Prognosis; D011658:Pulmonary Fibrosis / Q000401:mortality / Q000503:physiopathology*; D012044:Regression Analysis; D012189:Retrospective Studies; D014797:Vital Capacity
keywords: FEV1/FVC; idiopathic pulmonary fibrosis; interstitial; lung disease; obstructive; prognosis