cc1868 CCJ Erratum <p>Statistics review 3: Hypothesis testing and <it>P </it>values</p> Whitley Elise editorial@ccforum.com Ball Jonathan editorial@ccforum.com

Lecturer in Medical Statistics, University of Bristol, UK

Lecturer in Intensive Care Medicine, St George's Hospital Medical School, London, UK

 Critical Care 1364-8535 2003 7 1 15 See related Review: http://ccforum.com/content/6/3/222 12617734 10.1186/cc1868 13 12 2002 2003 BioMed Central Ltd

An erratum to Statistics review 3: Hypothesis testing and Pvalues, by Elise Whitley and Jonathan Ball.

In the original version of this article [1], the words 'if the null hypothesis is true' were omitted from the first sentence of the first key message. The key message should have read as follows:

'A P value is the probability that an observed effect is simply due to chance, if the Null hypothesis is true; it therefore provides a measure of the strength of an association. A P value does not provide any measure of the size of an effect, and cannot be used in isolation to inform clinical judgement.'

 <p>Statistics review 3: Hypothesis testing and <it>P </it>values.</p> Whitley E Ball J Crit Care 2002 6 222 225 10.1186/cc1493 12133182 137449