Inpatient burden of juvenile dermatomyositis among children in the United States

BACKGROUND: Juvenile dermatomyositis (JDM) is a rare autoimmune disease that causes significant morbidity and quality of life impairment. Little is known about the inpatient burden of JDM in the US. Our goal was to determine the prevalence and risk factors for hospitalization with juvenile dermatomyositis and assess inpatient burden of JDM. METHODS: Data on 14,401,668 pediatric hospitalizations from the 2002–2012 Nationwide Inpatient Sample (NIS) was analyzed. ICD-9-CM coding was used to identify hospitalizations with a diagnosis of JDM. RESULTS: There were 909 and 495 weighted admissions with a primary or secondary diagnosis of JDM, respectively. In multivariable logistic regression models with stepwise selection, female sex (logistic regression; adjusted odds ratio [95% confidence interval]) (2.22 [2.05–2.42]), non-winter season (fall: 1.18[1.06–1.33]; spring (1.13 [1.01–1.27]; summer (1.53 [1.37–1.71]), non-Medicaid administered government insurance coverage (2.59 [2.26–2.97]), and multiple chronic conditions (2–5: 1.41[1.30–1.54]; 6+: 1.24[1.00–1.52]) were all associated with higher rates of hospitalization for JDM. The weighted total length of stay (LOS) and inflation-adjusted cost of care for patients with a primary inpatient diagnosis of JDM was 19,159 days and $49,339,995 with geometric means [95% CI] of 2.50 [2.27–2.76] days and $7350 [$6228–$8674], respectively. Costs of hospitalization in primary JDM and length of stay and cost in secondary JDM were significantly higher compared to those without JDM. Notably, race/ethnicity was associated with increased LOS (log-linear regression; adjusted beta [95% confidence interval]) (Hispanic: 0.28 [0.14–0.41]; other non-white: 0.59 [0.31–0.86]) and cost of care (Hispanic: 0.30 [0.05–0.55]). CONCLUSION: JDM contributes to both increased length of hospitalization and inpatient cost of care. Non-Medicaid government insurance was associated with higher rates of hospitalization for JDM while Hispanic and other non-white racial/ethnic groups demonstrated increased LOS and cost of care.