Patients with systemic autoimmune rheumatic diseases remain at risk for hospitalisation for COVID-19 infection in the Omicron era (2022-2024): a retrospective cohort study.

Objective: To investigate the risk factors for severe acute COVID-19 outcomes in the Omicron era among individuals with systemic autoimmune rheumatic diseases (SARDs).

Methods: We identified patients with confirmed SARDs and COVID-19 (positive PCR and/or antigen test) from 1 September 2022 to 15 March 2024 in the Mass General Brigham healthcare system. We estimated the associations of baseline characteristics with the odds of hospitalisation due to COVID-19 infection, verified by medical record review, using multivariable logistic regression.

Results: Of 2061 patients with SARDs and COVID-19 during the Omicron era (75% female, mean age 62.2 years), 134 (6.5%) were hospitalised due to COVID-19, mostly due to respiratory symptoms (84, 63%). Of those hospitalised, 11 (8%) required mechanical ventilation and 20 (15%) died. Older age (adjusted OR (aOR) 1.05 per year), Black race (vs White race, aOR 4.15), ever smoking (vs never, aOR 1.76), CD20 inhibitor use (vs antimalarial monotherapy, aOR 2.22) and glucocorticoid use (vs non-use, aOR 2.07) were significantly associated with higher odds of hospitalisation. Female sex (vs male, aOR 0.63), booster SARS-CoV-2 vaccination (vs initial series, aOR 0.49) and vaccination within either 3 months or 3-6 months prior to infection (aOR 0.41 and aOR 0.38, respectively, vs none within 12 months) were significantly associated with lower odds of hospitalisation.

Conclusions: Some patients with SARDs remain at higher risk of severe COVID-19 in the Omicron era. Patients who are older, Black, have more comorbidities, use CD20 inhibitors and/or glucocorticoids, or have not been vaccinated recently may benefit from risk-mitigating strategies, including booster vaccines and pre-exposure prophylaxis.