Funding for this research was provided by:
Korean Society of Pediatric Infectious Diseases (none)
Received: 3 June 2019
Accepted: 23 August 2019
First Online: 30 August 2019
Ethics approval and consent to participate
: No institutional review board approval or ethics statement was required as the present meta-analysis was retrospective.
: Not applicable.
: The authors declare that they have no competing interests.