Figure 1.

Workflow to define the AID cohort within N3C. A total of 15 231 849 patients were identified in the N3C enclave release version V90. Of these, 2 453 799 were COVID-19–positive between 1 January 2020 to 30 June 2022, as confirmed by an RT-PCR or Ag test, and had nonmissing values for age and gender. Patients were grouped based on whether they were diagnosed with an AID or exposed to an IS prior to COVID-19 diagnosis. See the Methods section for further details on inclusion/exclusion criteria. Abbreviations: Ag, antigen; AID, autoimmune disease; COVID-19, coronavirus disease 2019; IS, immunosuppressant; N3C, National COVID Cohort Collaborative; RT-PCR, reverse transcription-polymerase chain reaction; U07.1, 2023 ICD-10-CM Diagnosis Code for COVID-19.