Outcomes with and without outpatient SARS-CoV-2 treatment for patients with COVID-19 and systemic autoimmune rheumatic diseases: A retrospective cohort study

OBJECTIVE: To investigate temporal trends, severe outcomes, and rebound among systemic autoimmune rheumatic disease (SARD) patients according to outpatient SARS-CoV-2 treatment. METHODS: We performed a retrospective cohort study investigating outpatient SARS-CoV-2 treatments among SARD patients at Mass General Brigham (23/Jan/2022–30/May/2022). We identified SARS-CoV-2 infection by positive PCR or antigen test (index date=first positive test) and SARDs using diagnosis codes and immunomodulator prescription. Outpatient treatments were confirmed by medical record review. The primary outcome was hospitalization or death within 30 days following the index date. COVID-19 rebound was defined as documentation of negative then newly-positive SARS-CoV-2 tests. The association of any vs. no outpatient treatment with hospitalization/death was assessed using multivariable logistic regression. RESULTS: We analyzed 704 SARD patients with COVID-19 (mean age 58.4 years, 76% female, 49% with rheumatoid arthritis). Treatment as outpatient increased over calendar time (p<0.001). A total of 426(61%) received outpatient treatment: 307(44%) with nirmatrelvir/ritonavir, 105(15%) with monoclonal antibodies, 5(0.7%) with molnupiravir, 3(0.4%) with outpatient remdesivir, and 6(0.9%) with combinations. There were 9/426 (2.1%) hospitalizations/deaths among those treated as outpatient compared to 49/278 (17.6%) among those with no outpatient treatment (adjusted odds ratio [aOR] 0.12, 0.05 to 0.25). 25/318 (8%) of patients who received oral outpatient treatment had documented COVID-19 rebound. CONCLUSION: Outpatient treatment was strongly associated with lower odds of severe COVID-19 compared to no outpatient treatment. At least 8% of SARD patients experienced COVID-19 rebound. These findings highlight the importance of outpatient COVID-19 treatment for SARD patients and the need for further research on rebound.