Influence of Interstitial Lung Disease on Systemic Sclerosis Hospitalizations, A National Study (2002-2020)

Abstract Systemic sclerosis (SSc) is an autoimmune connective tissue disorder that can cause generalized inflammation and is characterized by fibrosis of the skin, organs and vasculopathy. Limited SSc is more common and typically less serious and less frequent diffuse has a higher mortality rate due to end organ damage. One of the most common complications of SSc is interstitial lung disease (ILD). ILD is characterized by fibrosis, scarring, and inflammation of the lungs. ILD has a 30% prevalence and a 40% 10-year mortality in patients with SSc worldwide. Hospitalizations for SSc were abstracted from the 2002–2020 using the National Inpatient Sample (NIS), an all-payer administrative database in capturing 97% of hospital discharges in the Untied States. The primary aim was to evaluate whether in-patient mortality, length of stay (LOS), and hospital cost differed if SSc patients had underlying ILD. We estimated multivariable logistic regression and log-normal models controlling for age, biological sex, race/ethnicity, income, and hospital setting. ILD was associated with 88% greater adjusted odds of in-patient mortality (aOR 95% CI: 1.53 to 2.31, p < 0.001), 15% longer stays (aOR 95% CI: 1.04 to 1.28, p = 0.000), and 33% higher adjusted hospital costs (aOR 95% CI: 1.26 to 1.40, p < 0.001). These findings concluded that SSc with ILD has a significant impact on hospitalization outcomes.