COVID-19 more severe than influenza in patients with autoimmune disease
COVID-19 is more severe, with more complications and higher mortality, than influenza among patients with autoimmune disease, according to data published in Rheumatology.
“As having autoimmune diseases is a recognized risk factor for COVID-19 related complications, public health authorities around the world have advised mitigation strategies for those at risk,” Eng Hooi Tan, PhD, MPH, BSc, of the University of Oxford, in the United Kingdom, and colleagues wrote. “In the absence of a vaccine and a scarcity of proven therapeutic options, nonpharmacological measures such as shielding, case isolation, strict hand hygiene and social distancing are key measures to protect this vulnerable group of patients.”
“Thus far, characterization studies about COVID-19 infection in people with autoimmune conditions have been limited in sample size and mostly region-specific,” they added. “As such, COVID-19 outcomes among people with autoimmune conditions remain poorly understood. With the ongoing threat of COVID-19, clinical understanding of the characteristics and prognosis of patients with autoimmune conditions will facilitate the management of care for this group of patients.”
To analyze 30-day outcomes and mortality following hospitalization for COVID-19 in patients with autoimmune disease, compared with those for seasonal influenza among similar patients, Tan and colleagues conducted a network cohort study using electronic health records data from a multinational collection of institutions.
Electronic record sources included the Columbia University Irving Medical Center in New York; Optum, based in the United States; the U.S. Department of Veterans Affairs; and the Information System for Research in Primary Care-Hospitalization Linked Data in Spain. Claims data were obtained from Health Insurance and Review Assessment in South Korea, and IQVIA Open Claims, based in the United States.
The researchers included all patients with prevalent autoimmune diseases diagnosed or hospitalized with COVID-19 between January and June of 2020. These included 133,589 patients who were diagnosed, and 48,418 who were hospitalized, with COVID-19. The researchers compared these cases to 70,660 similar patients hospitalized with influenza from 2017 to 2018. The main outcomes were death and complications within 30 days of hospitalization.
According to the researchers, the most prevalent autoimmune diseases among those who developed COVID-19 were psoriasis, ranging from 3.5% to 27.9%; rheumatoid arthritis, 4% to 18.9%; and vasculitis, ranging from 3.3% to 17.5%).
In patients with autoimmune diseases who were hospitalized with COVID-19, the prevalence of hypertension (absolute standardized mean difference = 0.18 to 0.34), chronic kidney disease (ASMD = 0.17 to 0.25), heart disease (ASMD = 0.18 to 0.28), Type 2 diabetes (ASMD = 0.15 to 0.32), chronic obstructive pulmonary disease (ASMD = 0.11 to 0.20) and the use of anti-thrombotics (ASMD = 0.15 to 0.28) were all higher compared with those who were diagnosed but not hospitalized with COVID-19.
Meanwhile, compared with those hospitalized with influenza, patients hospitalized with COVID-19 demonstrated more respiratory complications, including pneumonia — at 12.6% to 53.2%, compared with 19.5% to 36.3% — and acute respiratory distress syndrome — at 14.7% to 42.8%, compared with 16.9% to 28.7% — and higher 30-day mortality — at 6.3% to 24.6%, compared with 2.2% to 4.4%.
“As having autoimmune disease is a risk factor for COVID-19 complications, our study was important to provide clinical understanding of the characteristics and prognosis of patients with autoimmune diseases,” Tan told Healio Rheumatology. “Most patients with autoimmune diseases hospitalized for COVID-19 were women, older and had previous comorbidities. Specifically, there was a higher prevalence of hypertension, chronic kidney disease and heart disease in these patients. Compared with influenza, patients admitted with COVID-19 had more complications and higher 30-day mortality.”
“COVID-19 is a more severe disease compared to influenza,” she added. “We found particular comorbidities that occurred more frequently in patients with autoimmune conditions hospitalized with COVID-19 vs. those diagnosed with COVID-19. Future studies should investigate predictors of poor outcomes associated with COVID-19 infection in this vulnerable group of patients.”