title: Evaluation of screening risk and nonrisk patients for methicillin-resistant Staphylococcus aureus on admission in an acute care hospital.
abstract: BACKGROUND
  Screening for methicillin-resistant Staphylocccus aureus (MRSA) is advocated as part of control measures, but screening all patients on admission to hospital may not be cost-effective.
  
  
  OBJECTIVE
  Our objective was to evaluate the additional yield of screening all patients on admission compared with only patients with risk factors and to assess cost aspects.
  
  
  METHODS
  A prospective, nonrandomized observational study of screening nonrisk patients ≤72 hours of admission compared with only screening patients with risk factors over 3 years in a tertiary referral hospital was conducted. We also assessed the costs of screening both groups.
  
  
  RESULTS
  A total of 48 of 892 (5%) patients was MRSA positive; 28 of 314 (9%) during year 1, 12 of 257 (5%) during year 2, and 8 of 321 (2%) during year 3. There were significantly fewer MRSA-positive patients among nonrisk compared with MRSA-risk patients: 4 of 340 (1%) versus 44 of 552 (8%), P ≤ .0001, respectively. However, screening nonrisk patients increased the number of screening samples by 62% with a proportionate increase in the costs of screening. A backward stepwise logistic regression model identified age > 70 years, diagnosis of chronic pulmonary disease, previous MRSA infection, and admission to hospital during the previous 18 months as the most important independent predictors to discriminate between MRSA-positive and MRSA-negative patients on admission (94.3% accuracy, P < .001).
  
  
  CONCLUSIONS
  Screening patients without risk factors increased the number of screenings and costs but resulted in few additional cases being detected. In a hospital where MRSA is endemic, targeted screening of at-risk patients on admission remains the most efficient strategy for the early identification of MRSA-positive patients.
authors.affiliation: Department of Clinical Microbiology, Education and Research Centre, Royal College of Surgeons in Ireland, Dublin, Ireland. eilishcreamer@rcsi.ie
authors.forename: Eilish
authors.initials: E
authors.lastname: Creamer
authors.forename: Sandra
authors.initials: S
authors.lastname: Galvin
authors.forename: Anthony
authors.initials: A
authors.lastname: Dolan
authors.forename: Orla
authors.initials: O
authors.lastname: Sherlock
authors.forename: Borislav D
authors.initials: BD
authors.lastname: Dimitrov
authors.forename: Deirdre
authors.initials: D
authors.lastname: Fitzgerald-Hughes
authors.forename: Toney
authors.initials: T
authors.lastname: Thomas
authors.forename: John
authors.initials: J
authors.lastname: Walsh
authors.forename: Joan
authors.initials: J
authors.lastname: Moore
authors.forename: Edmond G
authors.initials: EG
authors.lastname: Smyth
authors.forename: Anna C
authors.initials: AC
authors.lastname: Shore
authors.forename: Derek
authors.initials: D
authors.lastname: Sullivan
authors.forename: Peter
authors.initials: P
authors.lastname: Kinnevey
authors.forename: Piaras
authors.initials: P
authors.lastname: O'Lorcain
authors.forename: Robert
authors.initials: R
authors.lastname: Cunney
authors.forename: David C
authors.initials: DC
authors.lastname: Coleman
authors.forename: Hilary
authors.initials: H
authors.lastname: Humphreys
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002353:Carrier State / Q000453:epidemiology* / Q000382:microbiology; D003365:Costs and Cost Analysis; D003955:Diagnostic Tests, Routine / Q000191:economics / Q000379:methods*; D005260:Female; D006761:Hospitals; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000191:economics / Q000379:methods; D055624:Methicillin-Resistant Staphylococcus aureus / Q000302:isolation & purification*; D008875:Middle Aged; D015995:Prevalence; D011446:Prospective Studies; D012307:Risk Factors; D013203:Staphylococcal Infections / Q000453:epidemiology* / Q000382:microbiology