CHALICE (Children’s Head Injury Algorithm for the Prediction of Important Clinical Events) is a UK-derived decision rule to identify children with head injury who are at increased risk of death, need for neurosurgery or CT-detectable intracranial pathology.

Finding	Detail
Derivation cohort	Prospective multicentre study of 22,772 children <16 years with any severity of head injury presenting to 10 emergency departments in north-west England.
Primary outcome	Composite of death from head injury, need for neurosurgical intervention, or acute traumatic intracranial pathology on CT. Around 1% of enrolled children met this outcome.
Derivation performance	Sensitivity about 98% and specificity about 87% for clinically significant intracranial injury, with a modelled CT rate of roughly 14% if the rule is applied.
External validation	The APHIRST study of 20,137 children <18 years across 10 Australian and New Zealand emergency departments found CHALICE applicable to almost all presentations, with sensitivity just over 90% for clinically significant intracranial injury and negative predictive value >99%.

CHALICE informed earlier UK NICE head injury guidance and remains one of the major paediatric head injury rules internationally. Contemporary Australian and New Zealand pathways for mild to moderate head injury predominantly implement adapted PECARN-based algorithms, with CHALICE and other rules contributing to the evidence base rather than serving as the primary decision tool.

Use this calculator to support, not replace, clinical assessment. A CHALICE-positive result highlights children at higher risk who will usually merit CT head imaging and/or neurosurgical review. A negative result lowers, but does not eliminate, the risk of clinically important intracranial injury, particularly in infants, children with suspected non-accidental injury or bleeding disorders, and those with concerning clinical trajectories.

CHALICE Rule for Paediatric Head Injury