Rentsch et al., The Lancet Rheumatology,
doi:10.1016/S2665-9913(20)30378-7 (preprint 9/9, https://www.medrxiv.org/content/10.1101/2020.09.04.20187781v1) (Peer Reviewed)
Effect of pre-exposure use of hydroxychloroquine on COVID-19 mortality: a population-based cohort study in patients with rheumatoid arthritis or systemic lupus erythematosus using the OpenSAFELY platform
Observational database study of RA/SLE patients in the UK, 194,637 RA/SLE patients with 30,569 having >= 2 HCQ prescriptions in the prior 6 months, HCQ HR 1.03 [0.80-1.33] (HR 0.78 before adjustments).
70 patients with HCQ prescriptions died. One major problem is that there is no knowlege of medication adherence for these 70 - for example, it is possible that they were part of the expected percentage of patients that did not take the medication as prescribed, invalidating the result. Other limitations include confounding by use of bDMARDs and confounding by severity of rheumatological disease.
Rentsch et al., 9/9/2020, retrospective, population-based cohort, database analysis, United Kingdom, Europe, peer-reviewed, 34 authors.
risk of death, 3.0% higher, RR 1.03, p = 0.83, adjusted per study.
This study is excluded in meta analysis: not fully adjusting for the baseline risk differences within systemic autoimmune patients, medication adherence unknown and may significantly change results.
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.