Retrospective cohort study of RA and SLE patients not showing a significant difference in PCR+ cases. PCR+ does not distinguish asymptomatic cases or severity. There was only one death which was in the control group. No other information on severity is provided.
33% of the control group used HCQ within the last year. Remaining confounding by differences in the nature and severity of rheumatic disease is likely.
Jung et al., 12/11/2020, retrospective, South Korea, Asia, peer-reviewed, 6 authors.
risk of death, 59.3% lower, RR 0.41, p = 1.00, treatment 0 of 649 (0.0%), control 1 of 1417 (0.1%).
risk of COVID-19 case, 13.1% higher, RR 1.13, p = 0.86, treatment 15 of 649 (2.3%), control 31 of 1417 (2.2%), adjusted per study.