title: An external validation study of a clinical prediction rule for medical patients with suspected bacteraemia.
abstract: OBJECTIVE
  The objective of this study was to externally validate a clinical prediction rule (CPR)-the 'Shapiro criteria'-to predict bacteraemia in an acute medical unit (AMU).
  
  
  METHODS
  Prospectively collected data, retrospectively evaluated over 11 months in an AMU in the UK. From 4810 admissions, 635 patients (13%) had blood cultures (BCs) performed. The 100 cases of true bacteraemia were compared with a randomly selected sample of 100 control cases where BCs were sterile.
  
  
  RESULTS
  To predict bacteraemia (at a cut-off score of two points), the Shapiro criteria had a sensitivity of 97% (95% CIs 91% to 99%), specificity 37% (28% to 47%), positive likelihood ratio 1.54 (1.3 to 1.8) and a negative likelihood ratio of 0.08 (0.03 to 0.25). The area under the receiver operating curve was 0.80 (0.74 to 0.86), and the Hosmer-Lemeshow p value was 0.45.
  
  
  CONCLUSIONS
  A cut-off score of two points on the Shapiro criteria had high sensitivity to predict bacteraemia in a study of acute general medical admissions. Application of the rule in patients being considered for a BC could identify those at low risk of bacteraemia. Though the model demonstrated good discrimination, the lengthy number of variables (13) and difficulty automating the CPR may limit its use.
authors.affiliation: Intensive Care Department, Western Sussex Hospitals NHS Foundation Trust, Worthing Hospital, Worthing, West Sussex, UK.
authors.forename: Luke Eliot
authors.initials: LE
authors.lastname: Hodgson
authors.affiliation: Brighton and Sussex Medical School, Royal Sussex County Hospital, Brighton, East Sussex, UK.
authors.forename: Nicholas
authors.initials: N
authors.lastname: Dragolea
authors.affiliation: Intensive Care Department, Western Sussex Hospitals NHS Foundation Trust, Worthing Hospital, Worthing, West Sussex, UK.
authors.forename: Richard
authors.initials: R
authors.lastname: Venn
authors.affiliation: Primary Care and Population Sciences, University of Southampton, Southampton General Hospital, Southampton, Hampshire, UK.
authors.forename: Borislav D
authors.initials: BD
authors.lastname: Dimitrov
authors.affiliation: Intensive Care Department, The Royal Surrey County Hospital NHS Foundation Trust, Guildford, Surrey, UK.
authors.forename: Lui G
authors.initials: LG
authors.lastname: Forni
mesh_terms: D000368:Aged; D016470:Bacteremia / Q000175:diagnosis*; D016022:Case-Control Studies; D003661:Decision Support Techniques; D004739:England; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
keywords: bacterial; infectious diseases