[Correspondence] Head injury decision rules in children
The well designed Lancet study by Franz E Babl and colleagues1 compares three rules used for neuroimaging in paediatric patients with head trauma. As authors of the PECARN rules,2 we highlight several important points that require consideration. First, the three prediction rules compared were published in 2006, 2009, and 2010, before enrolment for the study by Babl and colleagues began. Therefore, the 10% CT rate noted by Babl and colleagues should be considered in that context, because CT ordering was likely to have been influenced by the rules.