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The normal range: it’s not normal and it’s not a range

Whyte, M.B. and Kelly, P. (2018) The normal range: it’s not normal and it’s not a range Postgraduate Medical Journal, 94. pp. 613-616.

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The NHS ‘Choose Wisely’ campaign places greater emphasis on the clinician-patient dialogue. Patients are often in receipt of their laboratory data and want to know whether they are normal. But what is meant by normal?

Comparator data, to a measured value, are colloquially known as the ‘normal range’. It is often assumed that a result outside this limit signals disease and a result within health. However, this range is correctly termed the ‘reference interval’. The clinical risk from a measured value is continuous, not binary. The reference interval provides a point of reference against which to interpret an individual’s results – rather than defining normality itself. This article discusses the theory of normality - and describes that it is relative and situational. The concept of normality being not an absolute state, influenced the development of the reference interval. We conclude with suggestions to optimise the use and interpretation of the reference interval, thereby facilitating greater patient understanding.

Item Type: Article
Divisions : Faculty of Health and Medical Sciences > School of Biosciences and Medicine
Authors :
Kelly, P.
Date : 13 November 2018
DOI : 10.1136/postgradmedj-2018-135983
Copyright Disclaimer : © Author(s) (or their employer(s)) 2019. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ. This is an open access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited, appropriate credit is given, any changes made indicated, and the use is non-commercial. See:
Uncontrolled Keywords : Normality; Biological variation; Mean
Depositing User : Clive Harris
Date Deposited : 03 Oct 2018 07:47
Last Modified : 16 Apr 2019 15:20

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