Funding for this research was provided by:
Received: 15 March 2020
Accepted: 13 August 2020
First Online: 4 September 2020
Ethics approval and consent to participate
: Not applicable. In compliance with national legislation, no ethical approval or informed consent was obtained for this systematic review, as it only contains data from previously published articles and no individual data.
: Not applicable.
: The authors declare that they have no competing interests.