COVID-19 Risk Comparison in Patients With IMIDs vs Matched Non-IMIDs from the General Population

A population-based COVID-19 study examined the incidence of testing and infection between patients with immune-mediated inflammatory diseases (IMIDs), determining that patients across all IMIDs were more likely to be tested for SARS-CoV-2, though this group tested positive for SARS-CoV-2 at the same rate as those without IMIDs.

The matched cohort study was conducted among adult residents from Ontario, Canada, and took place beginning in January 2020 until December 2020. Specific cohorts were created for rheumatoid arthritis (RA), psoriasis, psoriatic arthritis, ankylosing spondylitis, systemic autoimmune rheumatic diseases, multiple sclerosis (MS), iritis, inflammatory bowel disease (IBD), polymyalgia rheumatica, and vasculitis. Based on sociodemographic factors, each patient with an IMID was matched with five healthy patients to estimate the differences in likelihood, frequency, and severity of SARS-Cov-2 testing and infections. Multivariable logistic regressions was used to assess odds of infection.

Researchers studied 2,960,445 patients in total, including 493,499 patients with IMIDs and 2,466,946 patients without IMIDs. Upon analysis, the researchers found that patients with IMIDs were more likely to have been tested for SARS-CoV-2 at least once than those without IMIDs (27.4% vs 22.7%, respectively). Notably, 0.9% of tests were positive for SARS-CoV-2 in both groups.

Overall, wrote the study authors, patients with IMIDs had 20% higher odds of testing for SARS-CoV-2. Further, the odds of infection varied across the different IMIDs but was not significantly elevated for most IMID groups vs non-IMID controls. It was noted, however, that the odds of a SARS-CoV-2 infection were lower in patients with IBD or MS and marginally higher in patients with RA or iritis.

The main results of this COVID-19 comparison study between patients across all IMIDs vs patients without them showed that the incidence of SARS-CoV-2 infection was the same, but patients with IMIDs were more likely to be tested. The risk of SARS-CoV-2 infection only varied across four specific IMID subgroups.

Reference
Eder L, Croxford R, Drucker AM, et al. Understanding COVID-19 risk in patients with immune mediated inflammatory diseases: a population-based analysis of SARS-CoV-2 testing. Arthritis Care Res (Hoboken). Published online September 6, 2021. doi:10.1002/acr.24781