During both interventions the prevalence of rectal carriage of aminoglycoside-resistant gram-negative bacteria increased 7 % per month ( 95 % CI , 1 % -13 % ) during SDD ( P = .02 ) and 4 % per month ( 95 % CI , 0 % -8 % ) during SOD ( P = .046 ; P = .40 for difference ) .