Funding for this research was provided by:
Fondo de Investigación en Salud, Instituto Mexicano del Seguro Social (FIS/IMSS/PROT/G17/1683)
Text and Data Mining valid from 2018-10-30
Received: 12 March 2018
Accepted: 16 October 2018
First Online: 30 October 2018
Compliance with ethical standards
: The authors declare that they have no conflict of interest.