2254-2884 2254-2884 S2254-28842017000300267 Spain 00 09 2017 00 09 2017 20 3 267 270 1 2002 2 2 2014 3 SEN semFYC SEMG Semergen 2012 4 2007 19 4 4 19-24 5 6 2015 5