3.1 Study characteristics
We identified 14169 citations through the literature search, excluded
1706 titles and abstracts after initial screening. The final 146
full-text articles met all eligibility criteria(Figure 1). To analyze
COVID-19 prevalence, we included 68 observational studies totaling
384582 patients with ARD. For clinical outcomes, we included 85 studies
with 167554 patients with ARD diagnosed with COVID-19. Among these
studies, 56 were included with data from 127984 ARD patients diagnosed
with COVID-19 who have used anti-rheumatic drugs to explore the effect
of anti-rheumatic drugs on clinical outcomes of COVID-19 in autoimmune
diseases. We divided the anti-rheumatic medications used by patients
into three classes:GC, csDMARDs, and bDMARDs, and we also analyzed the
anti-TNF therapy separately. The characteristics and outcomes of the
included studies are summarized in Supplementary Material p2.