Outcomes of COVID-19 Omicron variant in patients with rheumatoid arthritis: a nationwide Greek cohort study.

Objectives: Patients with RA were at increased risk for COVID-19-associated hospitalization and death during the first year of the pandemic in Greece. We aimed to examine their outcomes after the SARS-Cov-2 Omicron, a more contagious but with milder clinical impacts variant, prevailed.

Methods: A retrospective, nationwide study was conducted between 1 January 2022 and 30 June 2022 in all RA patients under treatment and matched (1:5) on age, sex and region of domicile random general population comparators. Confirmed SARS-CoV-2 infections, hospitalizations and deaths, anti-rheumatic medications, prior COVID-19, vaccinations and anti-viral medications were recorded.

Results: Among 34 182 RA patients, infections (n = 5569, 16.29%), hospitalizations (n = 489, 1.43%) and deaths (n = 106, 0.31%) were more frequent than among comparators. Incidence rates per 1000 person/years of infection [IRR (95% CI):1.19 (1.16, 1.23)], hospitalization [IRR (95% CI):2.0 (1.82, 2.24)], and death [IRR (95% CI):1.81 (1.44, 2.27)] were increased in RA despite better vaccination coverage (89% vs 84%) and more frequent use of anti-viral medications (2.37% vs 1.08). Logistic regression analysis after correcting for age, sex, vaccinations, prior COVID-19, and anti-viral medications in SARS-CoV-2 infected RA patients and comparators revealed increased risk of hospitalization (OR: 2.02, 95% CI: 1.79, 2.27) and death [OR: 1.73, (95% CI: 1.36, 2.20)] in RA. Among infected RA patients, rituximab treatment conferred increased risks for hospitalization [OR: 6.12, (95% CI: 2.89, 12.92)] and death [OR: 12.06 (95% CI: 3.90, 37.31)], while JAK inhibitors increased only hospitalization risk [OR: 2.18 (95% CI: 1.56, 3.06)].

Conclusion: RA remains a risk factor for hospitalization and death in an era of a relatively low COVID-19 fatality rate, pointing to the need of perseverance in vaccination programs and wider use of anti-viral medications.