Prevalence and out-patient medical costs of comorbid conditions in patients with rheumatoid arthritis

Abstract

Objectives: To evaluate the prevalence, types, and out-patient direct medical costs of comorbid conditions in patients with RA in Thailand.

Methods: Information of the patients with RA treated by rheumatologists with at least one disease modifying antirheumatic drugs (DMARDs), including demographic data, RA-related medication types and treatment costs, comorbidity-related medication types and treatment costs, and total direct medical costs, was captured from King Chulalongkorn Memorial Hospital databases.

Results: The data from 684 patients with RA were included for analysis. The majority of the patients were prescribed combined DMARDs, while only 2.5% received biologics. Comorbid conditions were reported in 434 patients (63.5%). The most common comorbid condition was hypertension (51.2%). Advanced age and presence of healthcare coverage was associated with comorbid conditions. The average annual cost of non-RA-related treatments in patients with comorbid diseases was 15 times the cost in those without comorbidities (1546 vs. 104 USD; P < 0.001) while the total direct medical cost in patients with comorbid conditions was twice that in patients without comorbid diseases (4118 vs. 2045 USD; P < 0.001). Parameters that influenced total direct medical costs were RA medications costs, comorbidity, healthcare coverage, patient's age, and types of DMARDs.

Conclusions: Comorbid conditions were common in this study. However, the major cost component incurred in RA patients was the costs of RA medications and services, while the out-patient costs of comorbid conditions accounted for approximately 38% of the total costs.

Keywords: Comorbid condition; Direct medical costs; Disease modifying antirheumatic drugs; Rheumatoid arthritis; Societal perspective.