Racial and ethnic associations with interstitial lung disease and healthcare utilization in patients with systemic sclerosis

Objective: Racial and ethnic differences in presentation and outcomes have been reported in SSc and SSc-interstitial lung disease (ILD). However, prior studies have limited diversity. We aim to evaluate if there are racial/ethnic differences associated with ILD, time intervals between SSc and ILD, and emergency department (ED) visit or hospitalization rates. Methods: Clinical and sociodemographic variables were extracted for 756 patients with SSc from longitudinal health records in an integrated health-system. Logistic regression models analysed the association of covariates with ILD and age at SSc-ILD. Healthcare outcomes were analysed with complementary log-log regression models. Results: Overall, 33.7% of patients in the cohort had an ILD code, with increased odds for Asian (odds ratio [OR], 2.60; 95% CI: 1.29, 5.28; P = 0.008) compared with White patients. The predicted age in years of SSc-ILD was younger for Hispanic (estimate, -6.5; 95% CI: -13, -0.21; P = 0.04) and Black/African American patients (-10; 95% CI: -16, -4.9; P < 0.001) compared with White patients. Black/African American patients were more likely to have an ILD code before an SSc code (59% compared with 20.6% of White patients), and the shortest interval from SSc to ILD (3 months). Black/African American (hazard ratio [HR], 2.59; 95% CI: 1.47, 4.49; P = 0.001) and Hispanic patients (HR 2.29; 95% CI: 1.37, 3.82; P = 0.002) had higher rates of an ED visit. Conclusion: We found that odds of SSc-ILD differed by racial/ethnic group; minoritized patients had earlier age of presentation and greater rates of an ED visit.