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The accuracy of clinical symptoms and signs for the diagnosis of serious bacterial infection in young febrile children: prospective cohort study of 15 781 febrile illnesses

BMJ 2010; 340 doi: (Published 20 April 2010) Cite this as: BMJ 2010;340:c1594
  1. Jonathan C Craig, senior staff specialist12,
  2. Gabrielle J Williams, clinical researcher1,
  3. Mike Jones, senior lecturer13,
  4. Miriam Codarini, PhD student1,
  5. Petra Macaskill, associate professor of biostatistics1,
  6. Andrew Hayen, senior lecturer in biostatistics1,
  7. Les Irwig, professor of epidemiology1,
  8. Dominic A Fitzgerald, senior staff specialist4,
  9. David Isaacs, senior staff specialist5,
  10. Mary McCaskill, senior staff specialist6
  1. 1Screening and Test Evaluation Program, School of Public Health, University of Sydney, Sydney, Australia
  2. 2Department of Nephrology, The Children’s Hospital at Westmead, Westmead, Australia
  3. 3Psychology Department, Macquarie University, North Ryde, Australia
  4. 4Department of Respiratory Medicine, The Children’s Hospital at Westmead, Westmead, Australia
  5. 5Department of Infectious Disease, The Children’s Hospital at Westmead, Westmead, Australia
  6. 6Department of Emergency Medicine, The Children’s Hospital at Westmead, Westmead, Australia
  1. Correspondence to: G J Williams gabriew4{at}
  • Accepted 11 February 2010


Objectives To evaluate current processes by which young children presenting with a febrile illness but suspected of having serious bacterial infection are diagnosed and treated, and to develop and test a multivariable model to distinguish serious bacterial infections from self limiting non-bacterial illnesses.

Design Two year prospective cohort study.

Setting The emergency department of The Children’s Hospital at Westmead, Westmead, Australia.

Participants Children aged less than 5 years presenting with a febrile illness between 1 July 2004 and 30 June 2006.

Intervention A standardised clinical evaluation that included mandatory entry of 40 clinical features into the hospital’s electronic record keeping system was performed by physicians. Serious bacterial infections were confirmed or excluded using standard radiological and microbiological tests and follow-up.

Main outcome measures Diagnosis of one of three key types of serious bacterial infection (urinary tract infection, pneumonia, and bacteraemia), and the accuracy of both our clinical decision making model and clinician judgment in making these diagnoses.

Results We had follow-up data for 93% of the 15 781 instances of febrile illnesses recorded during the study period. The combined prevalence of any of the three infections of interest (urinary tract infection, pneumonia, or bacteraemia) was 7.2% (1120/15 781, 95% confidence interval (CI) 6.7% to 7.5%), with urinary tract infection the diagnosis in 543 (3.4%) cases of febrile illness (95% CI 3.2% to 3.7%), pneumonia in 533 (3.4%) cases (95% CI 3.1% to 3.7%), and bacteraemia in 64 (0.4%) cases (95% CI 0.3% to 0.5%). Almost all (>94%) of the children with serious bacterial infections had the appropriate test (urine culture, chest radiograph, or blood culture). Antibiotics were prescribed acutely in 66% (359/543) of children with urinary tract infection, 69% (366/533) with pneumonia, and 81% (52/64) with bacteraemia. However, 20% (2686/13 557) of children without bacterial infection were also prescribed antibiotics. On the basis of the data from the clinical evaluations and the confirmed diagnosis, a diagnostic model was developed using multinomial logistic regression methods. Physicians’ diagnoses of bacterial infection had low sensitivity (10-50%) and high specificity (90-100%), whereas the clinical diagnostic model provided a broad range of values for sensitivity and specificity.

Conclusions Emergency department physicians tend to underestimate the likelihood of serious bacterial infection in young children with fever, leading to undertreatment with antibiotics. A clinical diagnostic model could improve decision making by increasing sensitivity for detecting serious bacterial infection, thereby improving early treatment.


  • We would like to thank all the emergency department physicians who diligently completed the structured medical assessments on nearly 20 000 children; without their contribution this project would not have been possible.

  • Contributors: JCC undertook the design of the study, funding applications, presentation of the results, and the writing of manuscript. GJW obtained ethics permission and took part in data collection, database design, monitoring and reporting, compilation of results, medical staff training, and reviewing the manuscript. MJ analysed and compiled the results, and reviewed manuscript. MC compiled and piloted the febrile assessment tool, undertook medical staff training, data collection, and interpretation, compiled the results, and reviewed the manuscript. PM contributed to the statistical analysis design, interpretation of the analysis, and manuscript review. AH undertook statistical analysis, presentation of results, and review of the manuscript. LI contributed to the study design and review of the manuscript. DAF and DI formulated the disease definitions, acted as members of the final diagnosis review committee, and undertook clinical interpretation of results and review of the manuscript. DAF also monitored the study during JCC’s absence. MMC facilitated the study in the emergency department, formulated the disease definitions, reviewed the febrile template, undertook training and support of emergency staff, and contributed to clinical interpretation of the results and review of the manuscript. All authors had full access to all data and analyses. JCC, GJW, and PM act as the guarantors.

  • Funding: This trial was funded by the National Health and Medical Research Council of Australia (programme grant numbers 211205 and 402764). The funding source had no influence on study design, data collection, analysis, interpretation of data, writing of the report, or on the decision to submit the paper for publication.

  • Conflicts of interest: All authors have completed the Unified Competing Interest form at (available on request from the corresponding author) and declare: (1) No financial support for the submitted work from anyone other than their employer; (2) No financial relationships with commercial entities that might have an interest in the submitted work; (3) No spouses, partners, or children with relationships with commercial entities that might have an interest in the submitted work; (4) No non-financial interests that may be relevant to the submitted work.

  • Ethical approval: The study had ethics approval through the University of Sydney Human Research Ethics committee and the Royal Alexandra Hospital for Children Ethics Committee.

  • Data sharing: No additional data available.

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