Funding for this research was provided by:
Consejo Nacional de Ciencia y Tecnología (7876, 87783, 262233, 26267M, SALUD-2010-01-139796, SALUD-2011-01-161930, and CB-2013-01-221628)
Received: 29 July 2020
Accepted: 5 November 2020
First Online: 20 November 2020
Ethics approval and consent to participate
: The study was conducted according to the guidelines laid down in the Declaration of Helsinki and all procedures involving human subjects/patients were approved by the institutional review boards of all participating institutions [the Mexican Social Security Institute (12CEI 09 006 14), the National Institute of Public Health (13CEI 17 007 36), and the Autonomous University of the Mexico State (1233008X0236)]. All participants provided written informed consent.
: Not applicable.
: The authors declare that they have no competing interests.