Accuracy of a clinical diagnosis of idiopathic pulmonary fibrosis. A study of 404 pulmonologists from 57 countries

Methods: We conducted an international study of IPF diagnosis among a large group of physicians and compared their diagnostic performance to a panel of IPF experts (n=34). Participants evaluated 60 consecutive cases of interstitial lung disease. Diagnostic agreement was measured using weighted kappa coefficient (κw). Outcome distinctions between IPF and other diffuse lung diseases were used to validate diagnostic accuracy for first-choice diagnoses of IPF and were compared using the C-index. Results: 404 physicians completed the study. Agreement for IPF diagnosis was higher among expert physicians (κw =0.65 [IQR 0.53-0.72], P 20 years experience and MDT meeting attendance independently predicted prognostic accuracy of IPF diagnosis. The prognostic accuracy of academic physicians with >20 years experience (C-index=0.72, [IQR 0.0-0.73], p=0.229)) and non-university hospital physicians with more than 20 years experience, attending weekly MDT meetings (C-index=0.72, [IQR 0.70-0.72], p=0.052), did not differ significantly (p=0.229 and p=0.052 respectively) from the expert panel (C-index=0.74 [IQR 0.72-0.75]. Conclusion: Experienced respiratory physicians working at university-based institutions make diagnoses of IPF with similar prognostic accuracy to an international panel of IPF experts. Regular MDT meeting attendance improves the prognostic accuracy of experienced non-university practitioners to levels achieved by IPF experts.