Epidemiology and clinical characteristics of interstitial lung disease in patients with rheumatoid arthritis from the JointMan database

Interstitial lung disease (ILD) is a progressive fibrotic disease associated with rheumatoid arthritis (RA); real-world data for evaluating RA–associated ILD (RA–ILD) are limited. We evaluated prevalence, time to onset, clinical characteristics and prognostic factors in patients diagnosed with RA (n = 8963) in the Discus Analytics JointMan database (2009–2019) with and without ILD. ILD prevalence was 4.1% (95% confidence interval 3.7–4.5); > 90% had an ILD diagnosis after RA diagnosis (mean time to onset 3.3 years). At baseline, a higher proportion of patients with RA–ILD were older (> 65 years), male, with history of chronic obstructive pulmonary disease (COPD) compared with patients in the RA cohort. Patients in the RA–ILD cohort were likely to have more severe RA characteristics and joint evaluation compared with patients without ILD, at baseline and before/after ILD diagnosis. In this large, real-world database patients with (vs without) ILD had a higher burden of RA characteristics. Previously established risk factors for RA–ILD were confirmed (age, baseline COPD, anti-cyclic citrullinated peptide positivity, C-reactive protein, Clinical Disease Activity Index score); thus, recognition of these factors and tracking routine disease activity metrics may help identify patients at higher risk of RA complications and lead to improved diagnosis and earlier treatment.