Prognostic prediction for newly diagnosed patients with idiopathic interstitial pneumonia: JIPS Registry (NEJ030)

Background: Prognostic factors in patients with newly diagnosed idiopathic interstitial pneumonia (IIP) have rarely been analyzed using prospective data. This study investigated prognostic factors in patients with IIP. Methods: Central interstitial lung disease (ILD) experts established the diagnoses for fibrotic ILD. Prognostic factors using baseline data, including the pathological confidence level of usual interstitial pneumonia (UIP) assessed on a 0%–100% linear analog scale by high-resolution CT (HRCT), pulmonary function tests, and patient-reported outcomes were investigated. Results: Overall, 866 eligible patients were registered. Patients with unclassifiable idiopathic interstitial pneumonia (n = 272) survived longer than those with idiopathic pulmonary fibrosis (IPF) (n = 469) (hazard ratio [HR] = 0.67; [95% confidence interval [CI]: 0.47–0.95]; P = 0.022); however, IPF as IIPs classification was not a significant prognostic factor at diagnosis (P = 0.577). UIP pattern on HRCT, age, body mass index, forced vital capacity, diffusing capacity of the lungs for carbon monoxide, and St. George's Respiratory Questionnaire were risk factors for survival (P < 0.05). Patients with proposed progressive pulmonary fibrosis (PPF) had poorer prognoses than those without proposed PPF (HR = 5.63; [95% CI: 3.17–10.00]; P < 0.001). Patients with progressive fibrosing ILD (PF-ILD) had poorer prognoses than those without PF-ILD (HR = 7.85; [95% CI: 3.38–18.3]; P < 0.001). Conclusions: A prospective registry of patients with newly diagnosed IIP provided evidence that the UIP pattern on HRCT by analog scale was a prognostic predictor. Proposed PPF and PF-ILD were valuable for discriminating prognosis. (JIPS Registry, ClinTrials.gov, NCT03041623).