Received: 14 March 2021
Accepted: 12 June 2021
First Online: 5 July 2021
: This study was approved by the ethics committee of the School of Public Health of the University of Kinshasa (approval number: ESP / CE / 29/2020). Participation of human research subjects conformed to institutional review board guidelines, applicable laws and the World Medical Association Declaration of Helsinki. Written informed consent was waived owing to the use of deidentified retrospective data.
: Not applicable.
: The authors declare that they have no competing interests.