The most common preparation approaches were MBP alone ( 54.3 % ) , MBP + oral antibiotics ( 18.8 % ) , and oral antibiotics alone ( 4.2 % ) , although significant variation was found in hospital-specific rates for each approach ( MBP alone : 0-96 .1 % , MBP + oral antibiotics : 0-83 .6 % , orals alone : 0-91 .6 % , p < 0.0001 ) .