Characteristics of hospitalized dermatomyositis patients with underlying malignancy: a nationally representative...

Little is known regarding characteristics of hospitalized dermatomyositis (DM) patients. Understanding the unique characteristics of hospitalized DM patients with underlying malignancy is important in guiding development of specific work-up and treatment algorithms.

We aim to characterize the inpatient burden of DM patients with malignancy (DM malignancy), determine unique characteristics of DM-malignancy inpatients, and assess trends and predictors of cost of care and length of stay for hospitalized DM-malignancy patients.

Hospitalized DM patients with and without malignancy were characterized and compared using 2009-2015 National Inpatient Sample. Associated malignancies, risk factors for malignancy, and trends/predictors for cost of care and length of stay were evaluated using multivariable models.

Prevalence of malignancies among hospitalized DM inpatients was 10.9%. Age > 40 years and female sex were significantly associated with increased malignancy risk in DM inpatients. Numerous malignancies were significantly more common in men with DM compared to women, including bronchial, non-Hodgkin's lymphoma, head/neck, bladder, esophageal, kidney, and stomach. The most common malignancies in women with DM were breast and ovarian. Head/neck carcinomas were more common in hospitalized DM patients than previous cohorts evaluating outpatients. Socioeconomic characteristics differed between DM patients with/without malignancy. The presence of underlying malignancy did not affect hospitalization cost, length of stay, or mortality in the hospitalized DM population. The economic burden of hospitalized DM patients is increasing over time.

DM inpatients with malignancy display numerous differences compared to DM inpatients without malignancy. Further research characterizing hospitalized DM patients is warranted in order to optimize work-up and treatment guidelines for these patients.