AB015. Current diagnostic approaches in ILD: ILD vs. non-specialty clinics

Background: The approach to diagnosing interstitial lung diseases (ILDs) has evolved. While high resolution computed tomography (HRCT) and multidisciplinary discussion are key components in the diagnostic process, the approval of pirfenidone and nintedanib for idiopathic pulmonary fibrosis (IPF) has spurred greater urgency to improve the diagnostic process. In this study, we evaluated responses from pulmonologist in ILD and non-specialty clinics to assess the current ILD diagnostic evaluation and impact of a novel genomic classifier under development.

Methods: A national survey targeting pulmonologists in ILD and non-specialty clinics to assess the current ILD diagnostic evaluation and the impact of a novel diagnostic test. Participants were practicing pulmonologists who evaluated at least ten ILD patients annually. Seventy-six physicians satisfied the screening criteria and completed the survey (16 ILD pulmonologists; 60 non-specialty pulmonologists). Data were collected from March 17–20, 2015.

Results: ILD physicians diagnosed more patients with ILD (median 100 vs. 43 patients, P=0.017) and IPF (median 40 vs. 20 patients, P=0.02) annually than non-specialty pulmonologists. HRCT was highly utilized in both ILD and non-specialty clinics (96% vs. 91%, P=0.08). ILD clinicians utilized invasive diagnostic procedures significantly less than non-specialty pulmonologists: bronchoalveolar lavage (BAL), 30% vs. 40% (P=0.022); transbronchial biopsy (TBB), 27% vs. 41% (P=0.002); surgical lung biopsy (SLB), 32% vs. 42% (P=0.021). Clinicians were provided clinical backgrounds and HRCT images for four patient cases and were queried regarding diagnostic/treatment plans. ILD pulmonologists were significantly more likely to recommend pirfenidone or nintedanib for patients with definite Usual Interstitial Pneumonia (UIP) on HRCT than non-specialty pulmonologists (81% vs. 38%, P=0.006). About 48% of non-specialty pulmonologists recommended BAL/TBB or SLB in this patient case despite classic clinical history and typical HRCT findings of IPF. In cases of possible UIP, the recommendation to biopsy was high and comparable between groups (53.2% for ILD pulmonologists and 60.9% for non-specialty pulmonologists, P=0.558).

Conclusions: Differences exist between the diagnostic and/or therapeutic approaches utilized by ILD and non-specialty pulmonologists in evaluating ILD patients. Enhanced strategies to evaluate ILDs are required as the field rapidly evolves.

Keywords: Interstitial lung diseases (ILDs); non-specialty clinics; pulmonologists; idiopathic pulmonary fibrosis (IPF)