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
Abstract
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.
Edited from bmj.com
#febrile #bacterial
