Funding for this research was provided by:
CIBERESP (Ciber of Epidemiology and Public Health, Spain)
Received: 18 September 2017
Accepted: 11 December 2017
First Online: 16 January 2018
Ethics approval and consent to participate
: Ethical approval was obtained from the research committee of the Andalusian School of Public Health.
: Not applicable.
: The authors declare that they have no competing interests.
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