Phenotype P was more likely than phenotype H to be resistant to methicillin ( OR , 4.38 ; 95 % CI , 1.59-12 .06 ; P = 0.004 ) and to be linked to 30-day postoperative patient cultures ( risk ratio , 36.63 [ risk difference , 0.174 ; 95 % CI , 0.019-0 .328 ] ; P < 0.001 ) .