Differences in hospital-associated multidrug-resistant organisms and Clostridium difficile rates using 2-day versus 3-day definitions.

We surveyed infection prevention programs in 16 hospitals for hospital-associated methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci, extended-spectrum ß-lactamase, and multidrug-resistant Acinetobacter acquisition, as well as hospital-associated MRSA bacteremia and Clostridium difficile infection based on defining events as occurring >2 days versus >3 days after admission. The former resulted in significantly higher median rates, ranging from 6.76% to 45.07% higher.