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.
Zappala
C J
CJ
Royal Brompton Hospital and National Heart and Lung Institute, London, UK.
Latsi
P I
PI
Nicholson
A G
AG
Colby
T V
TV
Cramer
D
D
Renzoni
E A
EA
Hansell
D M
DM
du Bois
R M
RM
Wells
A U
AU
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