Hospitalization burden and comorbidities of patients with rheumatoid arthritis in Spain during the period 2002–2017

BACKGROUND: Rheumatoid arthritis (RA) is a chronic autoimmune rheumatic disease that is associated with multiple comorbidities and has a significant economic impact on the Spanish health system. The objective of this study was to estimate the rates of hospitalization of rheumatoid arthritis in Spain, and describing hospitalization rates and their changing by age, region, RA variant, and when RA as a main cause of hospitalization or a comorbidity. METHODS: Observational descriptive study that reviewed hospital records from the CMBD. We included all hospitalizations of patients in Spain whose main diagnosis or comorbidity in the ICD-9-CM was rheumatoid arthritis during the period of 2002–2017. RESULTS: A total of 315,190 hospitalizations with the RA code were recorded; 67.3% were in women. The mean age of the patients was 68.5 ± 13.9 years. The median length of hospital stay was 7 days (IQR 3–11 days). In 29,809 of the admissions, RA was coded as the main diagnosis (9.4%). When RA was not coded as the main diagnosis, the most frequent main diagnoses were diseases of the circulatory system (18.9%) and diseases of the respiratory system (17.4%). The hospitalization rate during the period of 2002–2017 was 43.8 (95% CI: 43.7–44.0) per 100,000 inhabitants and constantly increased during the period. The total cost for the healthcare system was 1.476 million euros, with a median of 3542 euros per hospitalization (IQR 2646–5222 euros). CONCLUSIONS: In Spain, the hospitalization rate of patients with RA increased during the study period, despite the decrease in the hospitalization rate when RA was the main diagnosis.