A prospective cluster-randomized trial to implement the Canadian CT Head Rule in emergency departments.
BACKGROUND
The Canadian CT Head Rule was developed to allow physicians to be more selective when ordering computed tomography (CT) imaging for patients with minor head injury. We sought to evaluate the effectiveness of implementing this validated decision rule at multiple emergency departments.


METHODS
We conducted a matched-pair cluster-randomized trial that compared the outcomes of 4531 patients with minor head injury during two 12-month periods (before and after) at hospital emergency departments in Canada, six of which were randomly allocated as intervention sites and six as control sites. At the intervention sites, active strategies, including education, changes to policy and real-time reminders on radiologic requisitions were used to implement the Canadian CT Head Rule. The main outcome measure was referral for CT scan of the head.


RESULTS
Baseline characteristics of patients were similar when comparing control to intervention sites. At the intervention sites, the proportion of patients referred for CT imaging increased from the "before" period (62.8%) to the "after" period (76.2%) (difference +13.3%, 95% CI 9.7%-17.0%). At the control sites, the proportion of CT imaging usage also increased, from 67.5% to 74.1% (difference +6.7%, 95% CI 2.6%-10.8%). The change in mean imaging rates from the "before" period to the "after" period for intervention versus control hospitals was not significant (p = 0.16). There were no missed brain injuries or adverse outcomes.


CONCLUSIONS
Our knowledge-translation-based trial of the Canadian CT Head Rule did not reduce rates of CT imaging in Canadian emergency departments. Future studies should identify strategies to deal with barriers to implementation of this decision rule and explore more effective approaches to knowledge translation. (ClinicalTrials.gov trial register no. NCT00993252).
Stiell
Ian G
IG
Department of Emergency Medicine, Ottawa Hospital Research Institute, University of Ottawa, Ottawa, Ont. istiell@ohri.ca
Clement
Catherine M
CM
Grimshaw
Jeremy M
JM
Brison
Robert J
RJ
Rowe
Brian H
BH
Lee
Jacques S
JS
Shah
Amit
A
Brehaut
Jamie
J
Holroyd
Brian R
BR
Schull
Michael J
MJ
McKnight
R Douglas
RD
Eisenhauer
Mary A
MA
Dreyer
Jonathan
J
Letovsky
Eric
E
Rutledge
Tim
T
Macphail
Iain
I
Ross
Scott
S
Perry
Jeffrey J
JJ
Ip
Urbain
U
Lesiuk
Howard
H
Bennett
Carol
C
Wells
George A
GA
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002170:Canada; D016000:Cluster Analysis; D016001:Confidence Intervals; D006259:Craniocerebral Trauma / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017410:Practice Guidelines as Topic; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed