|Title||Predicting survival across chronic interstitial lung disease: the ILD-GAP model.|
|Publication Type||Journal Article|
|Year of Publication||2014|
|Authors||Ryerson, CJ, Vittinghoff, E, Ley, B, Lee, JS, Mooney, JJ, Jones, KD, Elicker, BM, Wolters, PJ, Koth, LL, King, TE, Collard, HR|
|Date Published||2014 Apr|
|Keywords||Aged, Alveolitis, Extrinsic Allergic, Chronic Disease, Connective Tissue Diseases, Female, Humans, Idiopathic Pulmonary Fibrosis, Lung Diseases, Interstitial, Male, Middle Aged, Models, Theoretical, Prognosis, Survival Rate|
BACKGROUND: Risk prediction is challenging in chronic interstitial lung disease (ILD) because of heterogeneity in disease-specific and patient-specific variables. Our objective was to determine whether mortality is accurately predicted in patients with chronic ILD using the GAP model, a clinical prediction model based on sex, age, and lung physiology, that was previously validated in patients with idiopathic pulmonary fibrosis.METHODS: Patients with idiopathic pulmonary fibrosis (n=307), chronic hypersensitivity pneumonitis (n=206), connective tissue disease-associated ILD (n=281), idiopathic nonspecific interstitial pneumonia (n=45), or unclassifiable ILD (n=173) were selected from an ongoing database (N=1,012). Performance of the previously validated GAP model was compared with novel prediction models in each ILD subtype and the combined cohort. Patients with follow-up pulmonary function data were used for longitudinal model validation.RESULTS: The GAP model had good performance in all ILD subtypes (c-index, 74.6 in the combined cohort), which was maintained at all stages of disease severity and during follow-up evaluation. The GAP model had similar performance compared with alternative prediction models. A modified ILD-GAP Index was developed for application across all ILD subtypes to provide disease-specific survival estimates using a single risk prediction model. This was done by adding a disease subtype variable that accounted for better adjusted survival in connective tissue disease-associated ILD, chronic hypersensitivity pneumonitis, and idiopathic nonspecific interstitial pneumonia.CONCLUSION: The GAP model accurately predicts risk of death in chronic ILD. The ILD-GAP model accurately predicts mortality in major chronic ILD subtypes and at all stages of disease.