1413-6538 1413-6538 S1413-65382014000400525 /10.1590/S1413-65382014000400005 Brazil 00 12 2014 00 12 2014 20 4 525 540

26 45 45 24 40 40 271-83 32 3 3 355-64 24 2 2 161-71 19 2 2 169-82 4 2 2 5-15 17 2 2 143-52 15 2 2 276-83