Accuracy of Community Diagnosis of Idiopathic Interstitial Pneumonias Referred to an Academic Medical Center. A Single Center Experience

Abstract

Purpose: Idiopathic Interstitial Pneumonias (IIPs) are a subgroup of the diffuse parenchymal lung diseases of unknown etiology and are characterized by varying degrees of inflammation and fibrosis. The IIPs have significant heterogeneity in their clinical course based on their specific clinicopathological subtype. A multidisciplinary diagnostic approach and referral to centers of expertise is endorsed by current multi-society guidelines. We sought to determine the diagnostic agreement between community diagnosis and final diagnosis of patients referred to our Interstitial Lung Disease Clinic. Methods: We performed a retrospective chart review (September 1, 2014-February 28, 2015) of all new patient visits for two of our physicians (J.H. and T.W.) at the Medical University of South Carolina (MUSC) Interstitial Lung Disease Clinic. We excluded all cases that that were not referred by community pulmonologists or referred for non-ILD diagnosis. We reviewed the referral diagnosis and final diagnosis in addition to the clinical, imaging and anatomic pathology data. The initial diagnosis was obtained from the referral notes of the community provider. The final diagnosis was obtained from the ILD clinic note incorporating thoracic radiology and pathology input. Results: Of 83 cases reviewed 45 met our inclusion criteria. We excluded 38 cases, 27 that were not referred for an ILD diagnosis, 8 were not referred by a community pulmonologist and 3 we found to be follow-up patients. Mean age 70+/-12, 62% (28/45) male, 69% (31/45) prior or current smokers, mean FVC % 66 +/- 21, mean DLCO % 54 +/- 23. We had a 62% (28/45) diagnostic agreement with the community providers. Idiopathic pulmonary fibrosis was the referral diagnosis for the majority of cases 62% (28/45) and diagnostic agreement was higher in this subset 82% (23/28). Conclusions: We identified that on evaluation at our ILD center approximately 40% of patients received a alternative diagnosis. Accurate diagnosis of IIPs has implications regarding management and prognosis. Prior studies describe higher diagnostic agreement within physicians at academic centers and an association of higher mortality with delayed access to a tertiary care center. Clinical Implications: Further research is needed to identify objective methods for improving the diagnostic accuracy of IIP. The clinical implications of referral delay are not completely understood. Our study is in agreement with prior literature and supports early referral of patients with presumed IIPs to centers of expertise.