title: The impact of a PCR assay for candidemia on antifungal drug prescribing in critical care: an interrupted time series pilot study.
abstract: OBJECTIVE
  To evaluate the feasibility of conducting a definitive study to assess the impact of introducing a rapid PCR-based test for candidemia on antifungal drug prescribing.
  
  
  METHODS
  Prospective, single centre, interrupted time series study consisting of three periods of six months' duration. The assay was available during the second period, during which the PCR assay was available for routine use by physicians Monday-Friday with guaranteed 24-h turnaround time. For each period total antifungal drug use, expressed as treatment-days, was recorded and an adjustment was made to exclude estimated use for proven candidemia. Also, during the intervention period, antifungal prescribing decisions for up to 72 h after each PCR result became available were recorded as either concordant or discordant with that result.
  
  
  RESULTS
  While overall antifungal use remained relatively stable throughout, after adjustment for candidemia, there was a 38% reduction in use following introduction of the PCR test; however, this was nonsignificant at the 95% level. During the intervention period overall concordance between the PCR result and prescribing decisions was 84%.
  
  
  CONCLUSIONS
  The PCR assay for candidemia was requested, prescribing decisions were generally concordant with the results produced and there was an apparent decrease in antifungal prescription, although this was sustained even after withdrawal of the intervention; these findings should be more thoroughly evaluated in a larger trial.
authors.affiliation: Department of Medical Microbiology, Kelvin Laboratories, The Royal Hospitals, Belfast Health and Social Care Trust, Belfast BT12 6BA, UK. ronan.mcmullan@belfasttrust.hscni.net
authors.forename: R
authors.initials: R
authors.lastname: McMullan
authors.forename: L
authors.initials: L
authors.lastname: Metwally
authors.forename: J A
authors.initials: JA
authors.lastname: Troughton
authors.forename: P V
authors.initials: PV
authors.lastname: Coyle
authors.forename: S
authors.initials: S
authors.lastname: Hedderwick
authors.forename: D F
authors.initials: DF
authors.lastname: McAuley
authors.forename: B V
authors.initials: BV
authors.lastname: McCloskey
authors.forename: S
authors.initials: S
authors.lastname: O'Hare
authors.forename: C H
authors.initials: CH
authors.lastname: Webb
authors.forename: R J
authors.initials: RJ
authors.lastname: Hay
mesh_terms: D000328:Adult; D000935:Antifungal Agents / Q000627:therapeutic use*; D002177:Candidiasis / Q000175:diagnosis*; D003422:Critical Care / Q000379:methods*; D016469:Fungemia / Q000175:diagnosis*; D006801:Humans; D008875:Middle Aged; D009172:Mycology / Q000379:methods*; D010865:Pilot Projects; D016133:Polymerase Chain Reaction / Q000379:methods*; D055656:Prescriptions / Q000706:statistics & numerical data*; D011446:Prospective Studies
chemical_list: D000935:Antifungal Agents