Robert J. Brison

The Canadian CT Head Rule for patients with minor head injury

BACKGROUND There is much controversy about the use of computed tomography (CT) for patients with minor head injury. We aimed to develop a highly sensitive clinical decision rule for use of CT in patients with minor head injuries. METHODS We carried out this prospective cohort study in the emergency departments of ten large Canadian hospitals and included consecutive adults who presented with a Glasgow Coma Scale (GCS) score of 13-15 after head injury. We did standardised clinical assessments before the CT scan. The main outcome measures were need for neurological intervention and clinically important brain injury on CT. FINDINGS The 3121 patients had the following characteristics: mean age 38.7 years); GCS scores of 13 (3.5%), 14 (16.7%), 15 (79.8%); 8% had clinically important brain injury; and 1% required neurological intervention. We derived a CT head rule which consists of five high-risk factors (failure to reach GCS of 15 within 2 h, suspected open skull fracture, any sign of basal skull fracture, vomiting >2 episodes, or age >65 years) and two additional medium-risk factors (amnesia before impact >30 min and dangerous mechanism of injury). The high-risk factors were 100% sensitive (95% CI 92-100%) for predicting need for neurological intervention, and would require only 32% of patients to undergo CT. The medium-risk factors were 98.4% sensitive (95% CI 96-99%) and 49.6% specific for predicting clinically important brain injury, and would require only 54% of patients to undergo CT. INTERPRETATION We have developed the Canadian CT Head Rule, a highly sensitive decision rule for use of CT. This rule has the potential to significantly standardise and improve the emergency management of patients with minor head injury.

Socioeconomic differences in childhood injury: a population based epidemiologic study in Ontario, Canada

Objective—To determine whether risks for childhood injury vary according to socioeconomic gradients. Design—Population based, retrospective study. The percentage of individuals living below the poverty line (described ecologically using census data) was the primary measure of socioeconomic status. Setting—Catchment area of a tertiary medical centre that provides emergency services to all area residents. Area residents aged 0–19 years during 1996 were included. Observations—Injuries that occurred during 1996 were identified by an emergency department based surveillance system. The study population was divided into socioeconomic grades based upon percentages of area residents living below the poverty line. Multiple Poisson regression analyses were used to quantify associations and assess the statistical significance of trends. Results—5894 childhood injuries were identified among 35 380 eligible children; 985 children with missing socioeconomic data were excluded. A consistent relation between poverty and injury was evident. Children in the highest grade (indicating higher poverty levels) experienced injury rates that were 1.67 (95% confidence interval 1.48 to 1.89) higher than those in the lowest grade (adjusted relative risk for grades 1-V: 1.00,1.10,1.22,1.42, 1.67; ptrend<0.001). These patterns were observed within age/sex strata; for home, recreational, and fall injuries; and for injuries of minor and moderate severities. Conclusions—Socioeconomic differences in childhood injury parallel mortality and morbidity gradients identified in adult populations. This study confirms that this health gradient is observable in a population of children using emergency department data. Given the population based nature of this study, these findings are likely to be reflected in other settings. The results suggest the need for targeted injury prevention efforts among children from economically disadvantaged populations, although the exact requirements of the optimal prevention approach remain elusive.

Prognostic value of the Quebec Classification of Whiplash-Associated Disorders

Study Design. Retrospective cohort. Objectives. 1) Evaluate the utility of the Québec Classification of Whiplash-Associated Disorders as an initial assessment tool; 2) assess its ability to predict persistence of symptoms at 6, 12, 18, and 24 months postcollision; 3) examine one potential modification to the Classification. Summary of Background Data. In 1995, a task force from Québec, Canada, developed the Québec Classification of Whiplash-Associated Disorders to assist health care workers in making therapeutic decisions. The Classification was applied to an inception cohort of patients presenting for emergency medical care following their involvement in a rear-end motor vehicle collision. Methods. All patients (n = 446) presenting to the only two emergency departments serving Kingston, Ontario, between October 1, 1995 and March 31, 1998 were considered for inclusion in the study. Eligible patients (n = 380) were categorized according to the Classification based on signs and symptoms documented in their emergency medical chart. Attempts were made to interview all patients shortly following and again 6 months after their collision. Patients were contacted at 12, 18, and 24 months postinjury only if sufficient time had elapsed between recruitment into and cessation of the study. Data were gathered regarding symptoms, treatments received, effects on usual activities, crash circumstances, and personal factors. Associations between initial Classification grade and the frequency/intensity of follow-up symptoms were quantified via multivariable analyses. Results. The Classification was prognostic in that risk for Whiplash-Associated Disorders at 6, 12, 18, and 24 months increased with increasing grade. Analyses supported modification of the Classification to distinguish between Grade II cases of Whiplash-Associated Disorders with normal or limited range of motion. The greatest risk for long-term symptoms was seen among the group of patients with both point tenderness and limited range of motion. Conclusion. The analyses of this study support the use of the Québec Classification of Whiplash-Associated Disorders as a prognostic tool for emergency department settings, and the authors propose a modification of the Classification using a subdivision of the Grade II category.

Traumatic spinal cord injury in Ontario, Canada

BACKGROUND Few population-based analyses of spinal cord injuries exist from which to base Canadian prevention initiatives. This study aimed to calculate rates of traumatic spinal cord injury for the province of Ontario and describe these injuries by several epidemiologic parameters. METHODS Two thousand three hundred eighty-five hospital admissions were studied for April 1, 1994, through March 31, 1999. RESULTS Annual age-standardized rates declined from a maximum of 46.2 hospitalizations per 1 million population (95% confidence interval, 42.1-50.3) to 37.2 per 1 million (95% confidence interval, 33.8-41.0). Male rates declined over the study period, whereas female rates remained stable. Leading external causes included unintentional falls (1,030 of 2,385 [43.2%]), especially among the elderly, and transport injuries (1,021 of 2,385 [42.8%]), especially among those aged less than 40 years. Intentional injuries were most commonly seen among those aged 20 to 39 years (48 of 86 [55.8%]). Misclassification of some elder fall cases as spinal cord injuries is a methodologic concern. CONCLUSION The results indicate the relative importance of several external causes of injury and are useful in establishing rational priorities for prevention.

Implementation of the Canadian C-Spine Rule: prospective 12 centre cluster randomised trial

Objective To evaluate the effectiveness of an active strategy to implement the validated Canadian C-Spine Rule into multiple emergency departments. Design Matched pair cluster randomised trial. Setting University and community emergency departments in Canada. Participants 11 824 alert and stable adults presenting with blunt trauma to the head or neck at one of 12 hospitals. Interventions Six hospitals were randomly allocated to the intervention and six to the control. At the intervention sites, active strategies were used to implement the Canadian C-Spine Rule, including education, policy, and real time reminders on radiology requisitions. No specific intervention was introduced to alter the behaviour of doctors requesting cervical spine imaging at the control sites. Main outcome measure Diagnostic imaging rate of the cervical spine during two 12 month before and after periods. Results Patients were balanced between control and intervention sites. From the before to the after periods, the intervention group showed a relative reduction in cervical spine imaging of 12.8% (95% confidence interval 9% to 16%; 61.7% v 53.3%; P=0.01) and the control group a relative increase of 12.5% (7% to 18%; 52.8% v 58.9%; P=0.03). These changes were significant when both groups were compared (P<0.001). No fractures were missed and no adverse outcomes occurred. Conclusions Implementation of the Canadian C-Spine Rule led to a significant decrease in imaging without injuries being missed or patient morbidity. Final imaging rates were much lower at intervention sites than at most US hospitals. Widespread implementation of this rule could lead to reduced healthcare costs and more efficient patient flow in busy emergency departments worldwide. Trial registration Clinical trials NCT00290875.

Development of a Clinical Prediction Rule for 30-Day Cardiac Events in Emergency Department Patients With Chest Pain and Possible Acute Coronary Syndrome

STUDY OBJECTIVE Evaluation of emergency department (ED) patients with chest pain who are at low risk for acute coronary syndrome is resource intensive and may lead to false-positive test results and unnecessary downstream procedures. We seek to identify patients at low short-term risk for a cardiac event for whom additional ED investigations might be unnecessary. METHODS We prospectively enrolled patients older than 24 years and with a primary complaint of chest pain from 3 academic EDs. Physicians completed standardized data collection forms before diagnostic testing. The primary adjudicated outcome was acute myocardial infarction, revascularization, or death of cardiac or unknown cause within 30 days. We used recursive partitioning to derive the rule and validated the model with 5,000 bootstrap replications. RESULTS Of 2,718 patients enrolled, 336 (12%) experienced a cardiac event within 30 days (6% acute myocardial infarction, 10% revascularization, 0.2% death). We developed a rule consisting of the absence of 5 predictors: ischemic ECG changes not known to be old, history of coronary artery disease, pain typical for acute coronary syndrome, initial or 6-hour troponin level greater than the 99th percentile, and age greater than 50 years. Patients aged 40 years or younger required only a single troponin evaluation. The rule was 100% sensitive (95% confidence interval 97.2% to 100.0%) and 20.9% specific (95% confidence interval 16.9% to 24.9%) for a cardiac event within 30 days. CONCLUSION This clinical prediction rule identifies ED chest pain patients at very low risk for a cardiac event who may be suitable for discharge. A prospective multicenter study is needed to validate the rule and determine its effect on practice.

A Systematic Review of Interventions to Prevent Childhood Farm Injuries

Objective. The goal of the study was to systematically review the global body of evidence surrounding the effectiveness of interventions for the prevention of acute pediatric agricultural injuries. A specific focus was the effectiveness of the North American Guidelines for Childrens Agricultural Tasks. Methods. Two reviewers independently screened studies and applied inclusion criteria on the basis of searches of 17 bibliographic databases (eg, Medline and Embase). We also screened reference lists of relevant studies and contacted experts in the area. Studies were included if they represented primary research, a comparison group was used, the study population included children or the intervention was directly applicable to children, and objective outcomes were reported. Two reviewers independently assessed the methodologic quality of included studies with the Downs and Black checklist. A qualitative analysis was performed because of extensive heterogeneity among studies. Results. We included 23 controlled studies, ie, 4 randomized, controlled trials, 5 controlled trials, and 14 quasiexperimental or observational studies. Only 8 of the relevant studies were published in peer-reviewed journals. School-based programs appeared to be effective at increasing short-term knowledge acquisition; outcomes were enhanced with active, hands-on participation, as opposed to passive activities. Safety day camps showed positive results for knowledge acquisition. Tractor training programs and community- and farm-based interventions showed mixed results. Studies examining the North American Guidelines for Childrens Agricultural Tasks suggested that uptake improves if dissemination is accompanied by a farm visit from a safety specialist or if information about child development principles is provided in conjunction with the guidelines. Conclusions. There is a lack of randomized, controlled trials and community-based trials in this area. Studies primarily examined intermediate outcomes, such as knowledge acquisition; few studies evaluated changes in injury rates. The interventions targeted at children and youths that were evaluated focused on educational interventions. There is both the need and potential for the development and evaluation of injury control interventions for children, particularly programs addressing lethal injuries to young/preschool-aged children.

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. Interpretation: 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)

Stages of development and injury patterns in the early years: a population-based analysis

BackgroundIn Canada, there are many formal public health programs under development that aim to prevent injuries in the early years (e.g. 0–6). There are paradoxically no population-based studies that have examined patterns of injury by developmental stage among these young children. This represents a gap in the Canadian biomedical literature. The current population-based analysis explores external causes and consequences of injuries experienced by young children who present to the emergency department for assessment and treatment. This provides objective evidence about prevention priorities to be considered in anticipatory counseling and public health planning.MethodsFour complete years of data (1999–2002; n = 5876 cases) were reviewed from the Kingston sites of the Canadian Hospitals Injury Reporting and Prevention Program (CHIRPP), an ongoing injury surveillance initiative. Epidemiological analyses were used to characterize injury patterns within and across age groups (0–6 years) that corresponded to normative developmental stages.ResultsThe average annual rate of emergency department-attended childhood injury was 107 per 1000 (95% CI 91–123), with boys experiencing higher annual rates of injury than girls (122 vs. 91 per 1000; p < 0.05). External causes of injury changed substantially by developmental stage. This lead to the identification of four prevention priorities surrounding 1) the optimization of supervision; 2) limiting access to hazards; 3) protection from heights; and 4) anticipation of risks.ConclusionThis population-based injury surveillance analysis provides a strong evidence-base to inform and enhance anticipatory counseling and other public health efforts aimed at the prevention of childhood injury during the early years.

Variation in management of recent-onset atrial fibrillation and flutter among academic hospital emergency departments.

STUDY OBJECTIVE Although recent-onset atrial fibrillation and flutter are common arrhythmias managed in the emergency department (ED), there is insufficient evidence to help physicians choose between 2 competing treatment strategies, rate control and rhythm control. We seek to evaluate variation in ED management practices for recent-onset atrial fibrillation and flutter patients at multiple Canadian sites and to determine whether hospital site was an independent predictor of attempted cardioversion. METHODS We conducted a cross-sectional survey by health records review on an observational cohort of all eligible adult recent-onset atrial fibrillation and flutter cases, with onset of symptoms less than 48 hours, treated at 8 academic hospital EDs during a 12-month period, and evaluated the variation in practice among sites for important management strategies. RESULTS Among the 1,068 study patients, 88.3% had atrial fibrillation and 11.7% had atrial flutter. The proportion of cases managed with rhythm control was 59.4% (interhospital range 42% to 85%) and, among these, electrocardioversion was attempted first for 44.2% (range 7% to 69%). There was variation in most management strategies, including use of rate control drugs 54.9% (range 37% to 65%), choice of procainamide as rhythm control drug 62.1% (range 15% to 89%), referral to cardiology in the ED 30.7% (range 16% to 64%), use of heparin 13.7% (range 1% to 29%), and outpatient cardiology referral 43.0% (range 30% to 65%). Adverse events were relatively uncommon and transient for patients undergoing attempts at pharmacologic (13.0%) or electrocardioversion (12.1%). Overall, 83.3% of patients were discharged home from the ED (range 73% to 90%). After controlling for 12 covariates, multivariate logistic regression found that factors independently associated with attempted cardioversion were age (odds ratio [OR] 0.97; 95% confidence interval [CI] 0.95 to 0.98), history of electrocardioversion (OR 2.73; 95% CI 1.56 to 4.80), associated heart failure (OR 0.29; 95% CI 0.09 to 0.95), and hospital site (ORs ranged from 0.38 to 3.05). CONCLUSION We demonstrated a high degree of variation in management approaches for recent-onset atrial fibrillation and flutter patients treated in academic hospital EDs. Individual hospital site, age, previous cardioversion, and associated heart failure were independent predictors for the use of rhythm control.