et al., Annals of the Rheumatic Diseases, doi:10.1136/annrheumdis-2020-218500 (Letter)
Comparison of the percentage of SLE/RA patients on immunosuppressants that were taking HCQ, for COVID-19 diagnosis versus other infections or outpatient visits, finding a similar percentage in each case.
No mortality of severity information is provided to determine if HCQ treated patients fared better. No adjustment for concomitant medications or severity.
Singer et al., 8/5/2020, retrospective, database analysis, USA, North America, preprint, 3 authors.
risk of COVID-19 case, 9.0% higher, RR 1.09, p = 0.62, treatment 55 of 10700 (0.5%), control 104 of 22058 (0.5%).
Effect extraction follows pre-specified rules
prioritizing more serious outcomes. For an individual study the most serious
outcome may have a smaller number of events and lower statistical signficance,
however this provides the strongest evidence for the most serious outcomes
when combining the results of many trials.