Funding for this research was provided by:
Wellcome Trust Training Fellowships in Public Health and Tropical Medicine scheme (109949/Z/15/Z)
Wellcome Trust (213589/Z/18/Z)
Fundação de Amparo à Pesquisa do Estado da Bahia
Received: 20 January 2021
Accepted: 27 April 2021
First Online: 1 June 2021
: Due to the exclusive use of aggregate secondary data, no ethical approval was necessary.
: Not applicable.
: The authors declare that they have no competing interests.