CDR Blog

The Canadian C-Spine Rule

March 8, 2021
Emily Nguyen, Cathy Cao, Manasi Parikh, Alec Popa, Kelly Leung

Discussion

Clinically important Cervical Spine Injury (CSI) is defined as fracture, dislocation or mechanical instability of the cervical spine which requires specialist intervention (i.e. immobilisation or surgical intervention). However, clinically important CSI occurs in only about 2-10% of blunt trauma patients with potential CSI(1) . The Canadian C-spine Rule (CCR) was derived and validated to be a highly sensitive clinical decision rule used to rule out clinically important CSI in trauma patients with potential cervical spine injury(2,3).

The Derivation of C-spine rules was conducted through a 3-year prospective cohort study including a sample of 8924 adult patients from 10 Canadian Emergency Departments in large hospitals. Patients were enrolled if they presented with blunt trauma to the head/neck, were alert and oriented with GSC 15, and had stable vital signs. The primary outcome was clinically important C-spine injury as identified on radiography. Using the derived clinical algorithm, the C-spine rules was able to correctly identify all 151 clinical important C-spine injuries, yielding sensitivity of 100% (95% CI, 98%-100%) and 42.5% specificity (95% CI, 40%-44%) by cross-validation(2) . The derivation process closely followed the methodological standard for CDR derivation— including a large sample size, with predictors and primary outcome measures clearly defined and presented in the study population, assessment of predictors and outcome was done in a blinded fashion, and the rule algorithm made clinical sense for utility in the ED setting(4).

The C-spine rule was successfully validated in large prospective studies at 9 emergency departments across Canada, and again validated in UK hospitals (3,5). The rule has also undergone impact analysis in a large, randomized impact trial at 12 Canadian emergency departments, with results showing a significant decrease of 12.8% in imaging, while still able to maintain quality standard of care when the rule was implemented (6).

We classified the Canadian C-Spine Rule as CDR Level 1. Through rigorous derivation, validation and impact studies of the high sensitivity C-spine rule, it gives researchers and clinicians the confidence that the rule can be used in a wide variety of settings, with practical ability to change clinician behaviour, improve resource stewardship and enhance efficiency in patient care in the emergency departments.

Authors

Cathy Cao, BSc., MSc., MD Candidate at McMaster University, class of 2021. Cat is interested in Anatomical Pathology, and is an avid lover of art and petting all the good dogs.

Kelly Leung, BA&Sc., MSW., MD Candidate at McMaster University, class of 2021. Kelly is interested in pursuing Psychiatry. During her down time, she is most likely thinking about food, cats, or sleep.

Emily Nguyen, BSc, MD Candidate at McMaster University, class of 2021. Emily is interested in Family Medicine, and can be found running on trails or taking nature photographs in her free time.

Manasi Parikh, BHSc., MD Candidate at McMaster University, class of 2021. Manasi is interested in pursuing Family Medicine and in her free time explores trails, hikes and kayaks.

Alexander Popa, MD Candidate at McMaster University, class of 2021. Alexander is interested in pursuing Family Medicine, and in his free time is an avid sports fan of all things Toronto and enjoys cooking and eating good food.