2.1 Inclusion criteria
A broad web-based search was conducted to identify all citations published, or in the pre-print stage. Having narrowed down the search tailored to the aims of our study, we finalised the citations to be included as part of the meta-analysis by incorporating a predefined set of inclusion criteria.
1. The studies must report a clear distinction between use and non-use of ACEi/ARB as the two-comparator arms. If the studies provided data separately for ACEi or ARB then we intended to analyse the impact on outcomes independently. However, in the absence of non-segregation of data between ACEi or ARB, analysis will be performed for the combined use of ACEi and ARB.
2. Studies must include patients with SARS-CoV-2 infections only.
3. Severity of infection, death and hospitalisation was the primary outcomes of interest.
4. In the process of data analysis any additional outcome of importance could be included after arriving at a consensus.
5. All patients in the active-treatment arm must have been treated with ACEi/ARB.
We excluded all data presented in the form of commentaries, review articles, or case reports. Any data unrelated to SARS-CoV-2 infection were also excluded.