2.1 Data sources and search strategy
We searched for relevant studies published from inception to March 20, 2023, on CBM, CNKI, China Science and Technology Journal Database, WanFang Data, PubMed, Embase, Web of Science, Cochrane Library, and Medline, with no restrictions on publication language or primary outcome. The articles were retrieved using a combination of subject terms and free words. The relevant papers were identified using Medical Subject Headings (MeSH) terms: “COVID-19” and related free words. To conduct subgroup analyses with each diagnosis, we also used the MeSH terms for each specific disease, including “ARDs”, “Arthritis, Rheumatoid”, “Lupus Erythematosus, Systemic”, “Sjogren’s Syndrome”, “Antiphospholipid Syndrome”, “Spondylitis, Ankylosing”, “Arthritis, Psoriatic”, “Vasculitis”, “Gout”, “Connective Tissue Diseases”, “Scleroderma, Systemic”. In addition, we manually searched the reference lists of published systematic reviews and original articles. The search strategy were described in Supplementary Material p1.