Search strategy
The databases Medline, EMBASE, Scopus, Cochrane, and medRxiv were searched from January 2019 until February 2021. The search was limited to the English language and for systematic review articles. Search terms are listed in Supplementary file 1 .
Article selection
Article selection was conducted using Covidence software (9); 10% of the articles’ titles/abstracts and full texts were randomly selected and screened independently. The percentage of agreement was calculated for all independent validation, with >80% considered adequate (10).
Data extraction
A data extraction template in Microsoft Excel was piloted with 10% of reviews by NW and agreed for use by all authors. 10% of reviews were randomly selected and underwent independent data extraction; the percentage of agreement was calculated. Again, agreement >80% was considered adequate (10) . Data extracted from the reviews included: title; authors; year review published; study design; sample size; setting; population; exposure (e.g. ACEIs/ARBs, ACEIs, or ARBs); and outcomes (e.g. death, COVID-19 infection, hospitalisation).