title: What is nosocomial? Large variation in hospital choice of numerators and denominators affects rates of hospital-onset methicillin-resistant Staphylococcus aureus.
abstract: We calculated hospital-onset methicillin-resistant Staphylococcus aureus (HO-MRSA) rates for Orange County, California, hospitals using survey and state data. Numerators were variably defined as HO-MRSA occurring more than 48 hours (37%), more than 2 days (30%), and more than 3 days (33%) postadmission. Survey-reported denominators differed from state-reported patient-days. Numerator and denominator choices substantially impacted HO-MRSA rates.
authors.affiliation: Division of Infectious Diseases and Health Policy Research Institute, University of California Irvine School of Medicine, Irvine, California 92697, USA. rdatta@uci.edu
authors.forename: Rupak
authors.initials: R
authors.lastname: Datta
authors.forename: Melissa
authors.initials: M
authors.lastname: Kuo King
authors.forename: Diane
authors.initials: D
authors.lastname: Kim
authors.forename: Christopher
authors.initials: C
authors.lastname: Nguyen
authors.forename: Kristen
authors.initials: K
authors.lastname: Elkins
authors.forename: Adrijana
authors.initials: A
authors.lastname: Gombosev
authors.forename: Taliser R
authors.initials: TR
authors.lastname: Avery
authors.forename: Hildy
authors.initials: H
authors.lastname: Meyers
authors.forename: Michele
authors.initials: M
authors.lastname: Cheung
authors.forename: Susan S
authors.initials: SS
authors.lastname: Huang
mesh_terms: D015982:Bias; D002140:California / Q000453:epidemiology; D003428:Cross Infection / Q000453:epidemiology*; D019538:Health Care Surveys; D006801:Humans; D055624:Methicillin-Resistant Staphylococcus aureus / Q000302:isolation & purification*; D013203:Staphylococcal Infections / Q000453:epidemiology*