Racial/Ethnic variations in morbidity and mortality in Adult Onset Still's Disease: An analysis of national dataset.

OBJECTIVES: Adult Onset Still's Disease (AOSD) is a rare autoinflammatory disorder. There is relatively little known about the impact of social determinants of health on its outcomes. Our goal is to describe the racial/ethnic variations, morbidity and mortality of AOSD hospitalized patients in the US.

MATERIALS AND METHODS: Adult US hospitalized patients between 2009-13 from a nationwide inpatient sample (NIS) database with AOSD were identified using ICD-9 code 714.2. NIS is the largest all-payer US inpatient database with approximately 8 million hospitalizations yearly. Patients with other autoimmune diseases were excluded. We used descriptive statistics to summarize patient and hospital characteristics. We performed survey-weighted logistic regression models adjusting for confounders to study our primary outcome: in-hospital mortality.

RESULTS: Between 2009-13, 5,820 AOSD patients were hospitalized with a mean age of 53.6 (SE-0.61) years. 3817 (65.6%) were female, 56% white and 3% Asian. Macrophage Activating Syndrome (1.7%), Disseminated Intravascular Coagulation (DIC-1.1%) and Thrombotic Thrombocytopenic Purpura (0.4%), respectively, complicated the hospital course. There were 154 inpatient deaths in study period (mortality 2.6%). Mean age of patients who died in hospital was higher (62.4 years ± 3.1) and 13.9% were Asians. Patients of Asian origin had significantly higher odds of in-hospital death compared to whites (aOR = 6.39, 95% CI 1.77-23.1, p = 0.005). Mortality was significantly higher for patients whose hospital course was complicated by DIC (aOR = 29.69, 95% CI 5.5-160.41, p = 0.006).

CONCLUSIONS: In this national sample of patients hospitalized for AOSD, we found significant variations in In-hospital mortality.