Intramuscular tophus

Abstract

To characterize inpatient prevalence and resource utilization of patients with polymyositis (PM) and dermatomyositis (DM).Patients with PM/DM were identified from the Nationwide Inpatient Sample (NIS) database from the year 2005 to 2014 using ICD-9 diagnostic codes. The primary outcome of this study was inpatient prevalence of PM/DM in the United States across the span of 10 years. Secondary outcomes included reason for hospitalization, inpatient mortality, morbidity, hospital length of stay (LOS), utilization of specialized procedures/tests and expenditures. A cohort of patients without PM/DM was also identified from the same database to serve as comparators. Multivariate regression analysis was used to adjust for age, sex, ethnicity, comorbidities and hospital characteristics.A total of 160,528 admissions of patients with a diagnosis of PM/DM occurred in the study period, corresponding to the inpatient prevalence of 41.9 cases per 100,000 discharges. During admission, patients with PM/DM died more frequently than patients without PM/DM with an adjusted odds ratio (aOR) of 2.22 (P < 0.01). A significantly higher inpatient morbidity among patients with PM/DM was also observed as indicated by a significantly higher risk of shock (aOR 2.33; P < 0.01), acute kidney injury (aOR 1.12; P < 0.01), multi-organ failure (aOR 1.83; P < 0.01) and need for admission to intensive care unit (aOR 1.94; P < 0.01). Patients in the PM/DM had an average of 1.7 more days of LOS (P < 0.01). The mean hospital costs and total hospitalization charges for patients with PM/DM were significantly higher than patients without PM/DM with additional adjusted mean of $4,217 and $13,531, respectively, in the multivariate model. Patients with PM/DM underwent computerized tomography scan (aOR 1.90; P < 0.01), magnetic resonance imaging (aOR 1.68; P < 0.01) and angiography (aOR 1.15; P < 0.01) more often than comparators.Inpatient prevalence of PM/DM was higher than what would be expected from the overall incidence. Hospitalizations of patients with PM/DM were associated with significantly higher rate of mortality, morbidity and resource utilization.