The number of total and partial infirmity days was 126 for theAB group and 43 for the XB group , and 220 for the AB group and 93 for the XB group , respectively ( mean day difference = -4.15 ; 95 % CI -7.35 to -0.95 ; P = 0.0134 and mean day difference = -5.7 ; 95 % CI -10.01 to -1.39 ; P = 0.0116 , respectively ) .