Adherence to Canadian computed tomography head rule is associated with improved hospital performance metrics

Document Type

Conference Proceeding

Publication Date


Publication Title

Academic emergency medicine


Background and Objectives: The Michigan Emergency Department Improvement Collaborative (MEDIC) was established in 2015 as a quality improvement network of unaffiliated hospitals linked by a clinical data registry within a structured implementation and incentive program. One of the network's objectives is to lower unnecessary computed tomography for adult minor head injuries using the Canadian CT Head Rule (CCHR) which has previously been shown to safely reduce the number of Head CT studies. We examined whether adherence to the CCHR was associated with significant decreases in length of stay (LOS), number of total imaging studies, and rates of hospital admission. We also examined return visit data to assure no significant difference in outcomes.

Methods: Data from the MEDIC registry on ED visits from 6/1/2016-9/30/2019 was used to identify adult patients with a negative CCHR by chart review and classified into two populations: visits where providers either followed the recommendations of the rule and did not order HCT, or violated the recommendations of the rule by ordering HCT. Comparison populations were obtained through propensity score-matching on age, gender, insurance type, triage acuity score, time and day of presentation, and hospital of presentation. Covariate balance was validated through calculation of absolute standardized mean differences. Average LOS, number of imaging studies, admission rates, rate of return visits within 7 days, and whether HCT was obtained or severe head injury detected upon return were examined within these populations.

Results: In the patient populations where providers adhered to the recommendations not to obtain CT in patients with low risk (7,502), the LOS was lower (3.01 vs 4.25, p<0.0001), the mean number of imaging studies obtained was fewer (0.96 vs 3.26, p<0.0001), and the hospital admission rate was lower (1.71 vs 3.57, p<0.0001). No statistically significant difference was observed with respect to rate of return visit within 7 days (6.48 vs 5.93, p = 0.1626) irrespective of whether the return visit resulted in HCT (0.96 vs 0.69, p=0.0675) or whether severe head injury was identified (0.01 vs 0.00, p=0.3864).

Conclusion: Adherence to the recommendations of the CCHR is associated with lower LOS, fewer overall imaging studies, and decreased hospital admission rates without evident increase in return visits or missed significant findings.



First Page


This document is currently not available here.