Title | Prevalence and prognosis of unclassifiable interstitial lung disease. |
Publication Type | Journal Article |
Year of Publication | 2013 |
Authors | Ryerson, CJ, Urbania, TH, Richeldi, L, Mooney, JJ, Lee, JS, Jones, KD, Elicker, BM, Koth, LL, King, TE, Wolters, PJ, Collard, HR |
Journal | Eur Respir J |
Volume | 42 |
Issue | 3 |
Pagination | 750-7 |
Date Published | 2013 Sep |
ISSN | 1399-3003 |
Keywords | Aged, Aged, 80 and over, Biopsy, Case-Control Studies, Cohort Studies, Disease Progression, Female, Humans, Idiopathic Pulmonary Fibrosis, Kaplan-Meier Estimate, Longitudinal Studies, Lung, Lung Diseases, Interstitial, Male, Middle Aged, Prevalence, Prognosis, Proportional Hazards Models, Pulmonary Diffusing Capacity, Risk Factors, Severity of Illness Index, Smoking, Survival Rate, Tomography, X-Ray Computed, Vital Capacity |
Abstract | The aim of this study was to determine the prevalence, characteristics and outcomes of patients with unclassifiable interstitial lung disease (ILD) and to develop a simple method of predicting disease behaviour. Unclassifiable ILD patients were identified from an ongoing longitudinal cohort. Unclassifiable ILD was diagnosed after a multidisciplinary review did not secure a specific ILD diagnosis. Clinical characteristics and outcomes were compared with idiopathic pulmonary fibrosis (IPF) and non-IPF ILDs. Independent predictors of mortality were determined using Cox proportional-hazards analysis to identify subgroups with distinct disease behaviour. Unclassifiable ILD was diagnosed in 10% of the ILD cohort (132 out of 1370 patients). The most common reason for being unclassifiable was missing histopathological assessment due to a high risk of surgical lung biopsy. Demographic and physiological features of unclassifiable ILD were intermediate between IPF and non-IPF disease controls. Unclassifiable ILD had longer survival rates when compared to IPF on adjusted analysis (hazard ratio 0.62, p = 0.04) and similar survival compared to non-IPF ILDs (hazard ratio 1.54, p = 0.12). Independent predictors of survival in unclassifiable ILD included diffusion capacity of the lung for carbon monoxide (p = 0.001) and a radiological fibrosis score (p = 0.02). Unclassifiable ILD represents approximately 10% of ILD cases and has a heterogeneous clinical course, which can be predicted using clinical and radiological variables. |
DOI | 10.1183/09031936.00131912 |
Alternate Journal | Eur. Respir. J. |
PubMed ID | 23222877 |