This outcome was measured in paediatric patients who, in the opinion of the clinician, looked unwell. The results are similar to those of temperature in that about half of the children that developed an adverse event looked unwell but also a fifth of the patients who didn't develop a complication also looked unwell. Amman et al (2003) analysed appearance in sub-groups, appearance not reduced versus slightly reduced or severely reduced. The first comparison resulted in an acceptable sensitivity and specificity compared with the other studies but there were no clear definitions of this outcome in order to differentiate between ‘slightly reduced’ and ‘severely reduced’ appearance.