Title | A multidimensional index and staging system for idiopathic pulmonary fibrosis. |
Publication Type | Journal Article |
Year of Publication | 2012 |
Authors | Ley, B, Ryerson, CJ, Vittinghoff, E, Ryu, JH, Tomassetti, S, Lee, JS, Poletti, V, Buccioli, M, Elicker, BM, Jones, KD, King, TE, Collard, HR |
Journal | Ann Intern Med |
Volume | 156 |
Issue | 10 |
Pagination | 684-91 |
Date Published | 2012 May 15 |
ISSN | 1539-3704 |
Keywords | Age Factors, Female, Humans, Idiopathic Pulmonary Fibrosis, Lung, Lung Transplantation, Male, Middle Aged, Models, Statistical, Prognosis, Pulmonary Diffusing Capacity, Retrospective Studies, Risk Assessment, Vital Capacity |
Abstract | BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is a progressive fibrotic lung disease with an overall poor prognosis. A simple-to-use staging system for IPF may improve prognostication, help guide management, and facilitate research.OBJECTIVE: To develop a multidimensional prognostic staging system for IPF by using commonly measured clinical and physiologic variables.DESIGN: A clinical prediction model was developed and validated by using retrospective data from 3 large, geographically distinct cohorts.SETTING: Interstitial lung disease referral centers in California, Minnesota, and Italy.PATIENTS: 228 patients with IPF at the University of California, San Francisco (derivation cohort), and 330 patients at the Mayo Clinic and Morgagni-Pierantoni Hospital (validation cohort).MEASUREMENTS: The primary outcome was mortality, treating transplantation as a competing risk. Model discrimination was assessed by the c-index, and calibration was assessed by comparing predicted and observed cumulative mortality at 1, 2, and 3 years.RESULTS: Four variables were included in the final model: gender (G), age (A), and 2 lung physiology variables (P) (FVC and Dlco). A model using continuous predictors (GAP calculator) and a simple point-scoring system (GAP index) performed similarly in derivation (c-index of 70.8 and 69.3, respectively) and validation (c-index of 69.1 and 68.7, respectively). Three stages (stages I, II, and III) were identified based on the GAP index with 1-year mortality of 6%, 16%, and 39%, respectively. The GAP models performed similarly in pooled follow-up visits (c-index ≥71.9).LIMITATION: Patients were drawn from academic centers and analyzed retrospectively.CONCLUSION: The GAP models use commonly measured clinical and physiologic variables to predict mortality in patients with IPF. |
DOI | 10.7326/0003-4819-156-10-201205150-00004 |
Alternate Journal | Ann. Intern. Med. |
PubMed ID | 22586007 |
Grant List | HL086516 / HL / NHLBI NIH HHS / United States |