Introduction & Objectives
Patients with systemic autoimmune rheumatic diseases (ARDs) may be at a higher risk of severe outcomes from COVID-19 due to underlying immunodeficiency and/or immunosuppression, but results from studies to date have been conflicting. Findings from early case reports and series suggested that patients with rheumatic diseases generally had mild COVID-19 infections. However, comparative cohort studies from early pandemic epicenters in Wuhan, China, and Boston demonstrated up to threefold higher odds of mechanical ventilation in patients with rheumatic disease vs. comparators. With schools, workplaces and governments loosening physical distancing restrictions, patients with rheumatic diseases and healthcare providers remain concerned about the potentially heightened risk of severe outcomes from COVID-19.
This study was undertaken to evaluate the risks of severe outcomes in COVID-19 patients with systemic ARDs compared with COVID-19 patients without systemic ARDs.
Using a large multicenter electronic health record network, D’Silva et al. conducted a comparative cohort study of patients with systemic ARDs diagnosed as having COVID-19 (identified by diagnostic code or positive molecular test result) compared with patients with COVID-19 who did not have systemic ARDs, matched for age, sex, race/ethnicity and body mass index (primary matched model) and additionally matched for comorbidities and healthcare utilization (extended matched model).
In the systemic ARD cohort, the most common rheumatic diseases were rheumatoid arthritis (1,181 [50%]), systemic lupus erythematosus (528 [22%]), systemic sclerosis (317 [13%]), mixed or undifferentiated connective tissue disease (188 [8%]), systemic vasculitis (175 [7%]) and psoriatic arthritis (200 [8%]). Regarding immunomodulatory therapy, 1,304 patients (55%) were receiving glucocorticoids, 374 patients (16%) were receiving biologic or targeted synthetic disease-modifying anti-rheumatic drugs (DMARDs), and 981 patients (41%) were receiving conventional synthetic DMARDs, such as hydroxychloroquine (534 [22%]) or methotrexate (302 [13%]).
Thirty-day outcomes were assessed, including hospitalization, intensive care unit (ICU) admission, mechanical ventilation, acute renal failure requiring renal replacement therapy, ischemic stroke, venous thromboembolism and death.
The researchers initially identified 2,379 COVID-19 patients with systemic ARDs (mean age 58 years; 79% female) and 142,750 comparators (mean age 47 years; 54% female and 46% male). In the primary matched model (2,379 patients with systemic ARDs and 2,379 matched comparators with COVID-19 without systemic ARDs), patients with systemic ARDs had a significantly higher risk of hospitalization (relative risk [RR] 1.14 [95% confidence interval (95% CI) 1.03–1.26]), ICU admission (RR 1.32 [95% CI 1.03–1.68]), acute renal failure (RR 1.81 [95% CI 1.07–3.07]) and venous thromboembolism (RR 1.74 [95% CI 1.23–2.45]) than comparators, but did not have a significantly higher risk of mechanical ventilation or death. In the extended model, all risks were largely attenuated, except for the risk of venous thromboembolism (RR 1.60 [95% CI 1.14–2.25]).