A5V4d

Feverish illness in children
National Collaborating Centre for Women’s and Children’s Health
(NCC-WCH) [2007]
Adebayo Akande Research fellow
Monica Lakhanpaul Co-director in Child Health
Chia-Wen Lee Research fellow
Michael Corkett Information specialist
Rosie Crossley Work-Programme coordinator
Hannah-Rose Douglas Health economist
Peny Retsa Health economist
Acknowledgements
We would like to thank the Patient and Public Involvement Programme (PPIP) of the National Institute
for Health and Clinical Excellence (NICE) whose glossary was adapted for use in this guideline.
Francoise Cluzeau and Bobbie Lloyd also gave us support in conducting the Delphi consensus
technique. We are grateful to all the healthcare professionals and parents and carers that took part in
the consensus exercise. Diane Crawford gave us invaluable information about thermometers. We
obtained information about the burden of infectious diseases from Roderick MacFaul, and Matthew
Thompson kindly visited us to talk about his research on feverish illnesses in children presenting to
primary care.
1.2 Definitions used in the guideline
Definitions used in the guideline
At the first stage of the guideline development process, the GDG recognised that it was necessary to
have a definition of fever and also to decide what outcomes they would look for in terms of serious
illness.
It was necessary for the GDG to define certain terms that could be used as inclusion or exclusion
criteria for the guideline and literature searches.
Definition of fever
The GDG considered several definitions of fever that have been used in the scientific literature. The
GDG was aware that normal body temperature varies within and between individuals. It was also
recognised that the measurement of body temperature can vary with the site of measurement and
type of thermometer used. Accordingly, it was acknowledged that any definition of fever based on a
fixed body temperature would be arbitrary. It was therefore decided to use a well-recognised
physiological definition. 16 For the purposes of this guideline, fever was thus defined as ‘an elevation of
body temperature above the normal daily variation’.
It was also decided that the entry point into the guideline would be a child presenting to health
services with a measured or perceived fever. It was recognised that not all parents and carers have
access to thermometers and it was considered appropriate that the definition and entry point allow the
inclusion of children who are deemed to have a fever, with or without the use of a thermometer.
Despite agreeing on the above definition, the GDG recognised that other definitions of fever are used
in most of the scientific studies that appear in the literature searches and evidence tables. For these
studies, the inclusion criteria typically defined a fixed body temperature such as = 38°C or higher.
Definition of serious illness
Much of this guideline is devoted to identifying children with serious illnesses from among the many
who present to healthcare professionals with a fever. The GDG recognised that it would be necessary
to have a definition of serious illness to be used as an outcome measure in literature searches, etc. In
addition to mortality and morbidity, it was agreed that a list of diagnoses that represented serious
illnesses was needed. For the purposes of this guideline, serious illness with fever is defined as ‘an
illness with fever that could cause death or disability if there were a delay in diagnosis and treatment’.
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