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Volume 17 Supplement 4

Sepsis 2013

  • Poster presentation
  • Open Access

Prediction of bacteremia in emergency department patients with suspected infection: an external validation of a clinical decision rule

  • 1,
  • 1,
  • 2,
  • 1, 3,
  • 1,
  • 4 and
  • 3
Critical Care201317 (Suppl 4) :P23

  • Published:


  • Emergency Department
  • Positive Blood Culture
  • Prediction Rule
  • Emergency Department Patient
  • Matched Cohort


Bacteremia is a common clinical condition with an incidence of approximately 140 to 160 per 100,000 person-years. Since sepsis is a time-critical diagnosis, identification of emergency department (ED) patients at risk of bacteremia is therefore a priority. The study objective was to validate a previously published clinical decision rule for predicting a positive blood culture in ED patients with suspected infection based on minor criteria, major criteria and a total score [1].

Materials and methods

This was a retrospective matched cohort study, set in a large urban academic tertiary ED at Aarhus University Hospital, Aarhus, Denmark with approximately 56,000 patient visits annually. Adult ED patients with blood cultures obtained from 1 January through 31 December 2011. ED patients with blood culture-confirmed bacteremia were matched 1:3 to patients with negative cultures. The outcome was true bacteremia. Features of the clinical history, co-morbid illnesses, physical observations and laboratory tests were used to evaluate the performance of the clinical decision rule including calculation of the total score (Table 1). We report operating characteristics and the summary c-statistic for the decision rule.
Table 1

Decision rule

Major criteria

Minor criteria (1 point each)

Suspected endocarditis (3 points)

Age >65 years

Temperature >39.4°C (103.0°F) (3 points)

Temperature 38.3 to 39.3°C

Indwelling vascular catheter (2 points)





Hypotension (systolic blood pressure <90 mmHg)


White blood cell count >18,000 cells/mm3


Bands >5% (in our setting, immature cells >0.5%)


Platelets <150,000 cells/mm3


Creatinine >2.0 mg/dl (177 µl/l)

A blood culture is indicated by the rule if at least one major criterion or two minor criteria are present. Otherwise, cultures may be omitted. Points used to calculate the total score.


Among 1,526 patients, 105 (6.9%) patients were classified with true bacteremia. The sensitivity of the prediction rule was 94% (95% confidence interval (CI) 88 to 98%) and specificity 48% (95% CI 42 to 53%). Positive and negative predictive values were 37% (95% CI 32 to 44%) and 96% (95% CI 92 to 99%), respectively. The area under the receiver-operating characteristics curve was 0.83 ± 0.02 standard error (Figure 1).
Figure 1
Figure 1

Receiver operating characteristics curve (ROC) for external validation of the bacteremia prediction rule, calculated using the total score.


The clinical decision rule performed well in our ED setting and is likely to be a useful supplement to clinical judgment.



The CONSIDER Sepsis Network is a collaboration of clinical researchers with an interest in sepsis at Aarhus University Hospital, Aarhus, Denmark.

Authors’ Affiliations

Research Center for Emergency Medicine, Aarhus University Hospital, Aarhus, Denmark
Department of Infectious Disease, Aarhus University Hospital, Aarhus, Denmark
Research Department of Emergency Medicine, Beth Israel Deaconess Medical Center, Boston, MA, USA
Department of Clinical Microbiology, Aalborg University Hospital, Aarhus University Hospital, Aalborg, Denmark


  1. Shapiro , et al: Who needs a blood culture? A prospectively derived and validated prediction rule. J Emerg Med. 2008, 35: 255-264. 10.1016/j.jemermed.2008.04.001.View ArticlePubMedGoogle Scholar


© Jessen et al.; licensee BioMed Central Ltd. 2013

This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The Creative Commons Public Domain Dedication waiver ( applies to the data made available in this article, unless otherwise stated.