Abstract
OBJECTIVES: To identify risk factors for progression to severe COVID-19 and estimate the odds of severe COVID-19 associated with vaccination among patients with systemic lupus erythematosus (SLE). METHODS: This retrospective cohort study identified adults with SLE in the Merative™ MarketScan(®) Databases. Patients were continuously enrolled the year before 1 April 2020 (baseline) and had a COVID-19 diagnosis between 1 April 2020 and the earliest of death, enrolment end or 31 December 2021. Severe COVID-19 was defined as hospitalisation with a COVID-19 diagnosis. Demographics on 1 April 2020, baseline comorbidities, corticosteroid use ≤30 days before COVID-19 diagnosis and other SLE medication use ≤6 months before COVID-19 diagnosis were assessed. Vaccination was identified by claims for a COVID-19 vaccine or vaccine administration. Backward stepwise logistic regression estimated odds of progression to severe COVID-19 associated with patient characteristics and vaccination. RESULTS: Among 2890 patients with SLE with COVID-19, 500 (16.4%) had a COVID-19-related hospitalisation. Significant risk factors for progression to severe COVID-19 included rituximab (OR (95% CI) 2.92 (1.67 to 5.12)), renal failure (2.15 (95% CI 1.56 to 2.97)), Medicaid (vs Commercial; 2.01 (95% CI 1.58 to 2.57)), complicated hypertension (1.96 (95% CI 1.38 to 2.77)) and time of infection, among others. Vaccination had a significant protective effect (0.68(95% CI 0.54 to 0.87)) among all patients with SLE with COVID-19, but the effect was not significant among those with prior use of belimumab, rituximab or corticosteroids. CONCLUSIONS: Certain chronic comorbidities and SLE medications increase the odds of progression to severe COVID-19 among patients with SLE, but vaccination confers significant protection. Vaccine effectiveness may be attenuated by SLE treatments. Protective measures such as pre-exposure prophylaxis and booster vaccines should be encouraged among patients with SLE.