This study aims to examine the associations between comorbid conditions and healthcare utilization, medical charges, or mortality of patients with rheumatoid arthritis (RA). Nebraska state emergency department (ED) discharge, hospital discharge, and death certificate data from 2007 to 2012 were used to study the comorbid conditions of patients with RA. RA was defined using the standard International Classification of Diseases (ICD-9-CM 714 or ICD-10-CM M05, M06, and M08). There were more comorbid conditions in patients with RA than in patients without RA. Comorbid conditions were majorly related to healthcare utilization and mortality of patients with RA. In addition to injury, fracture, sprains, and strains, symptoms of cardiovascular and digestive systems, respiratory infection, and chronic obstructive pulmonary disease (COPD) were common comorbid conditions for ED visits. In addition to joint replacement and fracture, infections, COPD and cardiovascular comorbidities were common comorbid conditions for hospitalizations. Cardiovascular, cerebrovascular, and respiratory comorbidities, dementia, malignant neoplasm, and diabetes mellitus were common comorbid conditions for deaths of patients with RA. In addition, the numbers of comorbid conditions were significantly associated with the length of hospital stay and hospital charges for patients with RA. The findings in this study indicated that comorbid conditions are associated with healthcare utilization, medical charges, and mortality of patients with RA.
Keywords: Comorbid conditions; Healthcare utilization; Mortality; Rheumatoid arthritis.