Objective: We aimed to determine the incidence of and mortality after critical illness in rheumatoid arthritis (RA) compared with the general population, and to describe the risks for and characteristics of critical illness in patients with RA.
Methods: We used population-based administrative data from the Data Repository at the Manitoba Centre for Health Policy from 1984 to 2010, and linked clinical data from an intensive care unit (ICU) database to identify all persons with RA in the province requiring ICU admission. We identified a population-based control group, matched by age, sex, socioeconomic status, and region of residence. The incidence of ICU admission, reasons for, and mortality after ICU admission were compared between populations using age- and sex-standardized rates, rate ratios, Cox proportional hazards models, and logistic regression models.
Results: We identified 10,078 prevalent and 5560 incident cases of RA. After adjustment, the risk for ICU admission was higher for RA (HR 1.65, 95% CI 1.50-1.83) versus the matched general population. From 2000-2010, the annual incidence of ICU admission among prevalent patients was about 1% in RA, with a crude 10-year incidence of 8%. Compared with the general population admitted to ICU, 1 year after ICU admission, mortality was increased by 40% in RA. Cardiovascular disorders were the most common reason for ICU admission in RA.
Conclusion: Patients with RA have a higher risk for admission to the ICU than the general population and increased mortality 1 year after admission. Even with advances in management, RA remains a serious disease with significant morbidity.
Keywords: ADMINISTRATIVE DATA; CRITICAL ILLNESS; INCIDENCE; RHEUMATOID ARTHRITIS.