Application of the CHALICE clinical prediction rule for intracranial injury in children outside the UK: impact on head CT rate.

OBJECTIVE The children's head injury algorithm for the prediction of important clinical events (CHALICE) is one of the strongest clinical prediction rules for the management of children with head injuries. The authors set out to determine the impact of this rule on the proportion of head injured patients receiving a CT scan in a major Australian paediatric emergency department. DESIGN Retrospective cohort study. SETTING Tertiary paediatric hospital emergency department in Australia (67 000 patients/year). PATIENTS All head injured patients presenting to the emergency department in 2004. MAIN OUTCOME MEASURES Actual proportion of head injured patients receiving a CT scan compared with the proportion had the CHALICE algorithm been applied. RESULTS There were 1091 head injuries of all severities during the study period. 18% of head injured patients had a Glasgow Coma Scale <15, 19% a CT scan and 1.4% neurosurgical intervention. Application of the CHALICE algorithm would result in 46% receiving a CT scan. 303 patients who fit CHALICE criteria did not have a CT scan. These patients were managed with admission for observation or discharge and head injury instructions. Only five of these (1.6% or 0.5% of total head injuries) received a CT scan on representation for ongoing symptoms, four of which showed abnormalities on CT scan. CONCLUSIONS Application of the CHALICE rule to this non-UK dataset would double the proportion of CT scans, with an apparent small gain in delayed pick-up of CT abnormalities. The role of expectant observation in hospital or at home needs to be defined.