Inpatient burden and resource utilization of polymyositis and dermatomyositis: A 10-year Study of National Inpatient Sample

Patompong Ungprasert; Thapat Wannarong; Wisit Cheungpasitporn; Karn Wijarnpreecha; Charat Thongprayoon; Paul T Kroner

doi:10.1016/j.jbspin.2020.03.002

Inpatient burden and resource utilization of polymyositis and dermatomyositis: A 10-year Study of National Inpatient Sample

Joint Bone Spine. 2020 Jul;87(4):327-330. doi: 10.1016/j.jbspin.2020.03.002. Epub 2020 Mar 14.

Authors

Patompong Ungprasert¹, Thapat Wannarong², Wisit Cheungpasitporn³, Karn Wijarnpreecha⁴, Charat Thongprayoon⁵, Paul T Kroner⁴

Affiliations

¹ Department of Research and Development, Faculty of Medicine, Clinical Epidemiology Unit, Siriraj Hospital, Mahidol University, 3rd floor SIMR building, 2 Wanglang road, Bangkok, Thailand. Electronic address: p.ungprasert@gmail.com.
² Department of Neurology, University Hospitals Cleveland Medical Center/Case Western Reserve University, Cleveland, OH, USA.
³ Division of Nephrology, Department of Medicine, University of Mississippi Medical Center, Jackson, MS, USA.
⁴ Division of Gastroenterology and Hepatology, Department of Medicine, Mayo Clinic, Jacksonville, FL, USA.
⁵ Division of Nephrology, Department of Medicine, Mayo Clinic, Rochester, MN, USA.

PMID: 32184181
DOI: 10.1016/j.jbspin.2020.03.002

Abstract

Objectives: To characterize inpatient prevalence and resource utilization of patients with polymyositis (PM) and dermatomyositis (DM).

Methods: 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.

Results: 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.

Conclusions: 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.

Keywords: Dermatomyositis; Epidemiology; Expenditures; Hospitalization; Polymyositis.

MeSH terms

Comorbidity
Dermatomyositis* / diagnosis
Dermatomyositis* / epidemiology
Dermatomyositis* / therapy
Hospitalization
Humans
Inpatients
Polymyositis* / diagnosis
Polymyositis* / epidemiology
Polymyositis* / therapy
United States / epidemiology