1870-199X 1870-199X S1870-199X2020000400259 10.22201/fo.1870199xp.2020.24.4.81547 Ecuador 00 12 2020 00 12 2020 24 4 259 267

1. 2013 2. World Health Organization 3. 2017 74 107-21 4. 2015 76 7-26 5. Mayo Clinic 6. 2006 8 186-97 7. 2015 4 6-15 8. 2011 24 33-41 9. 1997 69 192-6 10. 2014