CanadiEM MVP Infographic Series – Comparison of PECARN, CATCH, and CHALICE Rules

In Infographics by Lauren BealsLeave a Comment

Editor’s Note – This post is one in a series of articles detailing “must know” papers in emergency medicine. Each post will summarize the findings of one study identified by the research of Bazak et al.1


Introducing the CanadiEM MVP Series

Evidence-based practice is critical for delivering quality emergency care, but with such a broad specialty identifying and recalling high-yield studies can be challenging. This is especially true for new EM learners, who are tasked with becoming evidence-informed while transitioning to practice.

To make this process easier, CJEM recently published a survey-based study aimed at compiling “must know” papers for emergency medicine trainees.

The study, conducted by Bazak et al, created a list of important papers based on the input of experts from specialty EM programs across the country.1 Participants were asked to generate a list of EM papers they considered to be the most influential, then rank the papers based on which they thought were the most important to include. Their final list contained 29 studies, 10 of which were supported by 100% of participants surveyed.

The CanadiEM MVP series will summarize these consensus papers using infographics, each of which will detail a different study’s objectives, methods and results.

The end goal of the series is to create an effective resource for recalling key papers, and to act as a primer for new trainees orienting themselves to EM evidence.


Comparison of PECARN, CATCH, and CHALICE Rules for Children with Minor Head Injuries2

To CT or not to CT, that is the question.

For any child in the ED with a GCS of 13-15 and a history of head trauma, providers are tasked with determining which risk is greater: the risk of radiation from a CT head, or the risk that their patient has developed a significant traumatic brain injury (TBI).

The decision is not always easy, with over 30% of children with a minor head injury undergoing CT even though less than 5% will be diagnosed with an intercranial bleed.34

To support physicians through their clinical reasoning, three clinical decision rules (CDRs) for CT in pediatric minor head trauma were developed; the Pediatric Emergency Care Applied Research Network (PECARN) rule3, Canadian Assessment of Tomography for Childhood Head injury (CATCH) rule5, and the Children’s Head injury Algorithm for the prediction of Important Clinical Events (CHALICE) rule.6

Each rule features a set of criteria that when absent categorizes the child as “low-risk” and negates the need for a CT. However, no studies had previously compared the sensitivity and specificity of each rule head-to-head.

To provide some clarification Easter et al. conducted a prospective cohort study of children under the age of 18 who presented to a tertiary ED with minor head trauma. Each child was assessed according to each of the three rules (PERCAN, CATCH, CHALICE) as well as against physician practice alone.

Among the 1009 children enrolled, 21 had clinically important traumatic brain injuries, and only PERCAN and physician practice correctly identified all 21 (sensitivity = 100%). CATCH and CHALICE had lower sensitivities (91% and 84%), but CHALICE had the highest specificity (85%) or any category tested.

Overall, the findings of Easter et al. clarified the strengths of each rule while increasing the likelihood that physicians incorporating a CDR into their practice use PECARN to avoid missing significant TBIs in pediatric patients.

The post was copyedited by Alvin Chin and uploaded by Lauren Beals. 


Bazak S, Sherbino J, Upadhye S, Chan T. Ascertaining top evidence in emergency medicine: A modified Delphi study. CJEM. 2019;21(2):291-295. [PubMed]
Easter J, Bakes K, Dhaliwal J, Miller M, Caruso E, Haukoos J. Comparison of PECARN, CATCH, and CHALICE rules for children with minor head injury: a prospective cohort study. Ann Emerg Med. 2014;64(2):145-152, 152.e1-5. [PubMed]
Kuppermann N, Holmes J, Dayan P, et al. Identification of children at very low risk of clinically-important brain injuries after head trauma: a prospective cohort study. Lancet. 2009;374(9696):1160-1170. [PubMed]
Mannix R, Meehan W, Monuteaux M, Bachur R. Computed tomography for minor head injury: variation and trends in major United States pediatric emergency departments. J Pediatr. 2012;160(1):136-9.e1. [PubMed]
Osmond M, Klassen T, Wells G, et al. CATCH: a clinical decision rule for the use of computed tomography in children with minor head injury. CMAJ. 2010;182(4):341-348. [PubMed]
Dunning J, Daly JP, Lomas J-P, et al. Derivation of the children’s head injury algorithm for the prediction of important clinical events decision rule for head injury in children. Archives of Disease in Childhood. 2006;91(11):885-891. doi:10.1136/adc.2005.083980

Lauren Beals

Lauren is a medical student at McMaster University and ClerkCast Co-founder. Her interests include FOAMed for medical learners, LGBTQ+ health, and care for survivors of violence.

Latest posts by Lauren Beals (see all)

Alvin is currently a PGY5 in the FRCP EM program at McMaster University. He serves as Director of Design for CanadiEM and has interests in knowledge translation and health innovation.