Received: 1 May 2020
Accepted: 10 June 2020
First Online: 22 June 2020
Ethics approval and consent to participate
: Not applicable. This study did not involve human participants. We analyzed publicly available information from scholarly journals and public web sites with preprint articles and registered clinical trials.
: Not applicable.
: Livia Puljak is Section Editor of the BMC Medical Research Methodology. Other authors declare no competing interests.