Competing interests
The authors declare that they have no competing interests.
Authors’ contributions
PA, JG and SR obtained the funds; the idea and design of the work are
thanks to PA, JG and PV; the questionnaire was administered by PA, SR and
PV; the processing of data was performed by SR; the analysis and the
interpretation of data was carried out by PA, SR, JG and PV. All the authors
have contributed to the critical revisions with important ideas and have
approved the final version.