0034-7450 0034-7450 S0034-74502020000400223 10.1016/j.rcp.2020.07.005 Peru Peru 00 12 2020 00 12 2020 49 4 223 224 1 2020 12 3 3 2 2020 287 112934 3 2020 1 4 2020 92 104504 5 6 2020 8 7 2020 17 9 8 2011 31 15-20