Marginal decline in forced vital capacity is associated with a poor outcome in idiopathic pulmonary fibrosis.
In therapeutic studies in idiopathic pulmonary fibrosis (IPF), the low prevalence of significant change in pulmonary functional tests (PFTs) has been a major constraint. The prognostic value of "marginal" changes in PFTs in IPF and fibrotic non-specific interstitial pneumonia (NSIP) was evaluated. In patients with biopsy-proven IPF (n = 84) and NSIP (n = 72), forced vital capacity (FVC) and diffusing capacity of the lung for carbon monoxide (D( L,CO)) trends at 6 months were categorised as "significant" (FVC >10%; D(L,CO) >15%) or "marginal" (FVC 5-10%; D(L,CO) 7.5-15%). Proportional hazards analysis and time-dependent receiver operating characteristic methodology were used to examine PFT trends against mortality. In IPF, reductions in FVC were significant in 22 cases (26%) and marginal in 19 cases (23%). Mortality was higher in patients with a significant decline in FVC (hazard ratio (HR) 2.80, 95% CI 1.54-5.06; p<0.001) and those with a marginal decline in FVC (HR 2.31, 95% CI 1.19-4.50; p = 0.01) than in those with stable disease. Progression-free survival was lower when the decline in FVC was marginal than in stable disease (HR 2.34, 95% CI 1.19-4.60; p = 0.01). Marginal changes in D(L,CO) in IPF and marginal changes in FVC and D (L,CO) in fibrotic NSIP did not provide useful prognostic information. Marginal change in FVC in IPF denotes a poor outcome. These findings are applicable to clinical practice and to the selection of patients with more progressive disease for therapeutic studies.
Royal Brompton Hospital and National Heart and Lung Institute, London, UK.
C J
CJ
Zappala
P I
PI
Latsi
A G
AG
Nicholson
T V
TV
Colby
D
D
Cramer
E A
EA
Renzoni
D M
DM
Hansell
R M
RM
du Bois
A U
AU
Wells
D002248:Carbon Monoxide / Q000378:metabolism; D005260:Female; D006801:Humans; D054990:Idiopathic Pulmonary Fibrosis / Q000401:mortality* / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care; D011237:Predictive Value of Tests; D015995:Prevalence; D011379:Prognosis; D016016:Proportional Hazards Models; D012307:Risk Factors; D012720:Severity of Illness Index; D014797:Vital Capacity
D002248:Carbon Monoxide