Incidence and prevalence of systemic sclerosis and systemic sclerosis with interstitial lung disease in the United States

Although systemic sclerosis (SSc) with interstitial lung disease (SSc-ILD) is a serious condition and incurs a substantial clinical burden, the epidemiology has not been well characterized. To estimate the incidence and prevalence of SSc and SSc-ILD among commercially insured adults in the United States. Adults with medical claims between 2011 and 2016 for SSc or SSc-ILD with and without high-resolution computed tomography scans were identified from the Optum Clinformatics Data Mart. Incidence and prevalence were calculated as rates per 100,000 person-years and 100,000 people, respectively. The crude and age- and sex-adjusted prevalence and incidence of SSc and SSc-ILD were estimated and stratified by year and geography. Sensitivity analyses were conducted based on different cohort identification algorithms. Overall, the crude incidence rates of SSc and SSc-ILD were 16.4 and 1.2 per 100,000 person-years, respectively, and the crude prevalence was 24.4 and 6.9 per 100,000 people, respectively. Patient characteristics were generally similar between the SSc and SSc-ILD groups. Mean age range was 59.2-59.9 years and 61.8-62.9 years in the SSc and SSc-ILD groups, respectively. SSc had an age- and sex-adjusted incidence rate of 15.1 per 100,000 person-years and an adjusted prevalence of 25.9 per 100,000 people. The adjusted incidence rate of SSc-ILD was 1.1 per 100,000 person-years and the adjusted prevalence was 7.3 per 100,000 people. This study provides current estimates of the national incidence and prevalence of SSc and SSc-ILD, which have not been previously well characterized. Further research in the future may help to support health management strategies and resource allocation for adults with SSc and SSc-ILD in the United States. This work was supported by Boehringer Ingelheim Pharmaceuticals, Inc. (BIPI), which reviewed the manuscript for medical and scientific accuracy, as well as intellectual property considerations. All authors are employed by BIPI and did not receive direct compensation related to the development of the manuscript.