1870-199X 1870-199X S1870-199X2008000400173 10.22201/fo.1870199xp.2008.12.4.15624 Mexico Mexico Mexico 00 00 2008 00 00 2008 12 4 173 176

1 1997 15-55 2 1985 1-60 3 1994 22 311-4 4 1998 55 81-5 5 2004 3 85-91 6 1995 52 189-94 7 Loimaranta v 2000 14 40-7 8 Organización Mundial de la Salud 1998 53-5 9 2006 63 6 6 215-9 10 1981 15 40-5 11 1999 27 406-12