Evaluation of an Active Strategy to Implement the Canadian CT Head Rule: Phase III
Overview
Each year, Canadian emergency department physicians treat 600,000 adults with "minor head injury" (concussion), i.e. loss of consciousness, amnesia, or disorientation in a patient who is now conscious and talking. Only a tiny fraction of these patients have an epidural hematoma (clot on the brain) requiring emergency surgery. Canadian emergency departments are extremely variable in their use of computed tomography (CT scans of the brain) and a small but important number of brain hematomas are missed in patients who do not have a CT scan. Indiscriminate use of high technology imaging such as CT adds considerably to our rising health care costs. In addition, CT scans are not available in many smaller Canadian hospitals and physicians must transfer potential brain injury cases to larger centers for testing. Unfortunately, there are no accurate and widely accepted guidelines to help clinicians determine which minor head injury patients should be referred for CT scan.
This research group recently developed and tested a highly accurate and reliable guideline called the "Canadian CT Head Rule" to help physicians be more accurate in their diagnosis of brain injury and to help standardize the use of CT without jeopardizing patient care. This new research project will evaluate the true effectiveness of the Rule when implemented with simple and inexpensive measures. This study will involve 7,200 patients in 12 busy emergency departments across Canada. This Canadian CT Head Rule is designed guide physicians in when to refer a concussion patient for CT scan and to optimize patient care. Widespread use will lead to better and more standardized care for patients with minor head injury and important savings for our health care systems.
Principal Investigator: Dr. Ian Stiell
Co-Investigators: Dr. George Wells, Dr. Jeremy Grimshaw, Doug Coyle, Dr. Howard Lesiuk
Duration of Study: Enrollment complete; currently being submitted for publication
For more information, please contact Cathy Clement.
Protocol Summary
Background
This renewal application builds on previous MRC/CIHR Health Services Research Committee funded grants to
determine feasibility (phase 0, MRC GR-13304D, 1995-96), develop a clinical decision rule for CT in
minor head injury (phase I, MRC MT-13700, 1996-99, N=3,121), and prospectively validate this
Canadian CT Head Rule (phase II, CIHR #42521, 2000-03, N=2,707), all part of the
U of Ottawa Group Grant in Decision Support Techniques (CIHR 2000-143).
The Canadian CT Head Rule is comprised of simple clinical variables and allows physicians to be much more
accurate in their diagnosis of brain injury and will standardize the use of CT without
jeopardizing patient care (The Lancet 2001).
In the recently completed prospective validation (phase II), we confirmed the accuracy and
reliability of the rule in 2,707 additional patients.
Objectives
The goal of phase III is to evaluate the effectiveness and safety of an active strategy
to implement the Canadian CT Head Rule into physician practice.
Specific objectives are to:
1) Determine clinical impact by comparing the intervention and control sites for:
a) CT Head ordering rates,
b) Missed neurological intervention cases,
c) Missed brain injuries,
d) Number of deaths,
e) Length of stay in ED, and
f) Patient satisfaction;
2) Determine sustainability of the impact;
3) Evaluate performance of the Canadian CT Head Rule, with regards to:
a) Accuracy,
b) Physician accuracy in interpretation, and
c) Physician comfort and compliance with use;
4) Conduct an economic evaluation to determine the potential for cost savings with widespread implementation;
5) Conduct an exploratory psychological process evaluation to examine whether physicians' intentions and behaviours can be predicted.
Methods
We propose a matched-pair cluster design study which compares outcomes during
3 consecutive 12-month "before", "after", and "decay" periods
at 6 pairs of "intervention" and "control" sites.
These 12 hospital ED sites will be stratified as "teaching" or "community" hospitals,
matched according to baseline CT head ordering rates, and
then allocated within each pair to either intervention or control groups.
During the "after" period at the intervention sites, simple and inexpensive strategies
will be employed to actively implement the Canadian CT Head Rule:
a) physician group discussion and consensus,
b) educational initiatives (lecture, posters, pocket cards), and
c) a process-of-care modification with a mandatory reminder of the Rule at the point of requisition for radiography.
These outcomes will be assessed:
1) Measures of clinical impact will compare the changes from "before" to "after"
between the intervention and control sites:
a) CT Head ordering proportions (the primary analysis);
b) Number of missed brain injuries;
c) Number of serious adverse outcomes;
d) Length of stay in ED;
e) Patient satisfaction.
2) Performance of the Canadian CT Head Rule:
a) Accuracy of the rule;
b) Physician accuracy of interpretation;
c) Physician comfort and compliance.
3) Economic evaluation measures:
a) CT head rate after discharge;
b) Length of stay in ED and hospital;
c) Hospital admission;
d) Neurological intervention;
e) Number of transfers.
4) Psychological Process Evaluation: Mail surveys of physicians before and after the intervention.
During the 12-month "decay" period, implementation strategies will continue, allowing us to
evaluate the sustainability of the effect.
We estimate a sample size of 2,400 patients in each period in order to have
adequate power to evaluate the main outcomes.
Importance
This implementation study (phase III) is an essential step in the process of
developing a new clinical decision rule / guideline for health care practitioners.
Phase I successfully derived the Canadian CT Head Rule and phase II confirmed
the accuracy and safety of the rule and, hence, the potential for physicians to improve care.
What remains unknown is the actual change in clinical behaviour that can be effected
by implementation of the Canadian CT Head Rule and whether implementation can be
achieved with simple and inexpensive measures.
We believe that the Canadian CT Head Rule has the potential to significantly limit health care costs and
improve the efficiency of patient flow in busy Canadian EDs.
Additional Information
Team Members
- OHRI members:
-
Dr. Ian Stiell, Principal Investigator
Cathy Clement, Senior Research Program Manager / Associate
Christine Leclair, Research Assistant
Dr. George Wells, Co-Investigator
Dr. Jeremy Grimshaw, Co-Investigator
Doug Coyle, Co-Investigator, University of Ottawa
Dr. Howard Lesiuk, Co-Investigator, The Ottawa Hospital
Erica Battram, Research Assistant
Kim Bradbury, Research Assistant
- Study Sites/Staff:
-
Dr. Douglas McKnight, Vancouver General Hospital
Dr. Marcia Edmonds, London HSC
Dr. Scott Ross, Sturgeon
Dr. Tim Rutledge, North York General Hospital
Dr. Anne Clarke, Surrey Memorial Hospital
Dr. Brian Rowe, University of Alberta
Dr. Jacques Lee & Dr. Michael Schull, Sunnybrook and Women's College HSC
Dr. Robert Brison, Kingston General Hospital
Dr. Iain MacPhail, Royal Columbian Hospital
Dr. Eric Letovsky, Credit Valley Hospital
Dr. Amit Shah, St. Thomas Elgin Hospital