The Traumatic Brain Injury Research Network of Korea (TBI Network) is an ED-based clinical research network for traumatic brain injury was constructed in 2007 and, at present, seven EDs are participating to this network: Seoul National University Hospital, Dongkuk University Ilsan Hospital, Seoul National University Boramae Medical Center, Jeju National University Hospital, Gyeongsang National University Hospital, Gachon University Gil Hospital, and Seoul National University Bundang Hospital.
Comparison of Clinical Performance of Cranial Computed Tomography Rules in Patients With Minor Head Injury: A Multicenter Prospective Study
Article first published online: 15 JUN 2011
© 2011 by the Society for Academic Emergency Medicine
Academic Emergency Medicine
Volume 18, Issue 6, pages 597–604, June 2011
How to Cite
Ro, Y. S., Shin, S. D., Holmes, J. F., Song, K. J., Park, J. O., Cho, J. S., Lee, S. C., Kim, S. C., Hong, K. J., Park, C. B., Cha, W. C., Lee, E. J., Kim, Y. J., Ahn, K. O., Ong, M. E. H. and for the Traumatic Brain Injury Research Network of Korea (TBI Network) (2011), Comparison of Clinical Performance of Cranial Computed Tomography Rules in Patients With Minor Head Injury: A Multicenter Prospective Study. Academic Emergency Medicine, 18: 597–604. doi: 10.1111/j.1553-2712.2011.01094.x
The Korean Centers for Disease Control and Prevention supported this study financially.
Presented at the European Congress on Emergency Medicine, Munich, Germany, September 2008.
The authors have no potential conflicts of interest to disclose.
Supervising Editor: James E. Olson, PhD.
- Issue published online: 15 JUN 2011
- Article first published online: 15 JUN 2011
- Received May 30, 2010; revisions received August 29, November 2, and December 6, 2010; accepted December 15, 2010.
ACADEMIC EMERGENCY MEDICINE 2011; 18:597–604 © 2011 by the Society for Academic Emergency Medicine
Objectives: The objective was to compare the predictive performance of three previously derived cranial computed tomography (CT) rules, the Canadian CT Head Rule (CCHR), the New Orleans Criteria (NOC), and National Emergency X-Ray Utilization Study (NEXUS)-II, for detecting clinically important traumatic brain injury (TBI) and the need for neurosurgical intervention in patients with blunt head trauma.
Methods: This was a prospective, multicenter, observational cohort study of patients with blunt head trauma from June 2008 to May 2009. The historical and physical examination components of the CCHR, NOC, and NEXUS-II were documented on a data collection form and the performance of each of the three rules was compared. Patient eligibility for each specific rule was defined exactly as previously described for each specific rule. To compare the three decision rules in terms of sensitivity and specificity, an intersection cohort satisfying inclusion criteria of all three decision rules was derived. The primary outcome was clinically important TBI, and the secondary outcome was neurosurgical intervention. The sensitivity and specificity of each rule were calculated with 95% confidence intervals (95% CIs). We also calculated the potential reduction rate in cranial CT scan utilization realized by theoretical implementation of these rules.
Results: A total of 7,131 patients were prospectively enrolled, including 692 (9.7%) with clinical TBI. Among the enrolled population, patients eligible for CCHR, NOC, and NEXUS-II totaled 696, 677, and 2,951, respectively. The sensitivity and specificity for clinically important brain injury were as follows: CCHR, 112 of 144 (79.2%, 95% CI = 70.8% to 86.0%) and 228 of 552 (41.3%, 95% CI = 37.3% to 45.5%); NOC, 91 of 99 (91.9%, 95% CI = 84.7% to 96.5%) and 125 of 558 (22.4%, 95% CI = 19.0% to 26.1%); and NEXUS-II, 511 of 576 (88.7%, 95% CI = 85.8% to 91.2%) and 1,104 of 2,375 (46.5%, 95% CI = 44.5% to 48.5%). The sensitivity and specificity for neurosurgical intervention were as follows: CCHR, 100% (95% CI = 59.0% to 100.0%) and 38.3% (95% CI = 34.5% to 41.9%); NOC, 100% (95% CI = 54.1% to 100.0%) and 20.4% (95% CI = 17.4% to 23.7%); and NEXUS-II, 95.1% (95% CI = 90.1% to 98.0%) and 41.4% (95% CI = 39.5% to 43.2%). Among the enrolled population, intersection patients of CCHR, NOC, and NEXUS-II totaled 588. The sensitivity and specificity for clinically important brain injury were as follows: CCHR, 73 of 98 (74.5%, 95% CI = 64.7% to 82.8%) and 201 of 490 (41.0%, 95% CI = 36.6% to 45.5%); NOC, 89 of 98 (90.8%, 95% CI = 83.3% to 95.7%) and 112 of 490 (22.9%, 95% CI = 19.2% to 26.8%); and NEXUS-II, 82 of 98 (83.7%, 95% CI = 74.8% to 90.4%) and 172 of 490 (35.1%, 95% CI = 30.9% to 39.5%). The potential reduction in emergency CT scans by using these decision rules would have been higher with the NEXUS-II rule (39.6%, 95% CI = 37.8% to 41.4%) than with the CCHR rule (27.0%, 95% CI = 23.7% to 30.3%) or NOC rule (20.2%, 95% CI = 17.2% to 23.3%).
Conclusions: For clinically important TBI, the three cranial CT decision rules had much lower sensitivities in this population than the original published studies, while the specificities were comparable to those studies. The sensitivities for neurosurgical intervention, however, were comparable to the original studies. The NEXUS-II rule showed the highest reduction rate for CT scans compared to other rules, but failed to identify all undergoing neurosurgical intervention for their original inclusion cohort.
Traumatic brain injury (TBI) is one of the most common injuries in the world. The estimated incidence of hospitalized patients with minor head injury is 100 to 300 per 100,000 person-years, representing approximately 6.7% of the 120 million total emergency department (ED) visits in the United States.1,2 The estimated incidence of patients visiting the ED with TBI is 453 per 100,000 person-years, of which 10.9% of the injuries are moderate to major and 89.1% are minor.3 Although intracranial complications of minor head injury are uncommon (6% to 21%), in a minority of cases (0.4% to 1.0%), life-threatening injuries requiring neurosurgical intervention occur, making the initial diagnostic evaluation more important.4–7
Cranial computed tomography (CT) is commonly considered the imaging modality of choice for the rapid and reliable diagnosis of intracranial traumatic lesions. Nearly 1 million blunt trauma patients undergo cranial CT imaging annually in the United States, but fewer than 60,000 (about 6%) prove to have significant intracranial injuries.8 The key to the initial evaluation of these patients is early detection of intracranial injuries using CT, followed by early neurosurgical intervention.9,10 However, imaging all patients presenting to the ED with blunt head trauma is not cost-effective and would exacerbate ED overcrowding. Therefore, initial selection of appropriate patients for cranial CT imaging is imperative. Several cranial CT decision rules have been independently developed to allow more selective ordering of CT scans, more rapid discharge of patients with minor head injury, and significant health care savings. The Canadian CT Head Rule (CCHR), New Orleans Criteria (NOC), and National Emergency X-Ray Utilization Study (NEXUS)-II criteria are the rules most widely used (Data Supplement S1, available as supporting information in the online version of this paper).8,11,12
The purpose of this study was to compare the clinical performance of the three cranial CT rules (CCHR, NOC, and NEXUS-II) for detecting the need for neurosurgical intervention and clinically important brain injury in patients with minor head trauma and to externally compare the clinical performance of the use of these rules in Korea.
This was a prospective observational study to compare the clinical performance of three different clinical decision rules for patients with minor head injury. The study was reviewed and approved by the institutional review board of each participating hospital; informed consent was waived after review of the protocol. This study was designed and financially supported by the Korean Centers for Disease Control and Prevention.
Study Setting and Population
This study was conducted at five tertiary academic EDs in Korea. Three were urban EDs with 30,000 to 50,000 annual visits each, and two were suburban EDs with 20,000 annual visits each (Data Supplement S2, available as supporting information in the online version of this paper). We enrolled consecutive patients who sustained acute blunt head trauma, between June 1, 2008, and May 31, 2009. Cases of acute blunt head trauma were defined as any patient who complained of blunt head trauma or had any physical evidence of head trauma, unless they had an obvious penetrating head injury.
Since 2006, we have been conducting injury surveillance and in-depth surveillance of injured patients presenting to the participating EDs (Data Supplement S3, available as supporting information in the online version of this paper). One of the goals of the surveillance network was to compare the clinical performance of these rules. We developed the in-depth surveillance registry including capturing the predictor variable for intracranial injury based on review of the existing literature, including descriptions of three CT rules. Data collected are based on the core data set of the International Classification of External Causes of Injuries proposed by the World Health Organization, including demographic data, prehospital emergency medical services records, clinical findings, medical treatment in the ED, ED disposition, and patient outcome.13
We stratified the subjects based upon their eligibility for the previously derived rules (CCHR, NOC, and NEXUS-II) to compare three head CT rules. Adding to this, we derived the intersection subjects of inclusion criteria of all three head CT rules to compare those in terms of sensitivity and specificity. Thus patients enrolled into the overall study were only considered for decision rules analyses if they met the inclusion/exclusion criteria of the specific decision rules (Table 1).
|Study design of CCHR||Study design of NOC||Study design of NEXUS-II|
|Inclusion criteria||Blunt trauma (LOC or amnesia or disorientation), GCS score 13–15, age ≥ 16 years, injury within the past 24 hours||Blunt trauma, (LOC or amnesia), GCS 15, age at least 3 years, injury within the past 24 hours, undergo cranial CT||All blunt trauma, undergo cranial CT|
|Exclusion criteria||Obvious penetrating skull injury, obvious depressed fracture, acute focal neurologic deficit, unstable vital sign, had a seizure before assessment in the ED, anticoagulation or bleeding tendency, revisit same event||Acute focal neurologic deficit||A delayed presentation, without blunt trauma|
Initial assessment was performed by attending emergency physicians or emergency medicine residents in a standard manner. Decisions to obtain cranial CT scans were made on the basis of the treating physicians’ clinical judgment and not dictated by study protocol. Currently, no agreed-upon set of criteria for CT scanning exists across the participating EDs. The presence or absence of the specific clinical variables of interest (decision rule variables) was documented on the standardized data collection form before CT imaging was performed (Data Supplement S3).
Primary surveillance data collection, including predictor variables for intracranial injury, was collected by general physicians (injury team), and most of the recorded information was supervised daily and revised by emergency physicians and a trained study coordinator. Outside of the study site investigators, the general physicians and emergency physicians did not know of the existence of the study or the study protocol.
Regular meetings for quality assurance of data and training programs for study coordinators and study site investigators were conducted at each of the five hospitals. A statistical assistant team guided and conducted a feedback process on data quality through monthly quality assurance meetings. Data variable definition and training material for data abstracters were used for maintenance of data quality.
We could not demand routine CT for all patients enrolled in the study because that was not current practice at the study hospitals. Consequently, all enrolled patients underwent a structured 6-month proxy outcome measure, administered by registered researchers over the telephone. According to this tool, information about admission or operation history in other hospitals and neurologic outcome at 6 months was obtained.
The predictor variables collected included: for NOC, age > 60 years, headache, vomiting, posttraumatic seizure, drug or alcohol intoxication, short-term memory deficit, and physical evidence of trauma above clavicles; for CCHR, age ≥ 65 years, Glasgow Coma Scale (GCS) score < 15 at 2 hours after injury, suspected open or depressed skull fracture, any sign of basal skull fracture, vomiting of two or more episodes, amnesia before impact > 30 minutes, and dangerous mechanism of injury; and for NEXUS-II, age ≥ 65 years, evidence of skull fracture, scalp hematoma, neurologic deficit, abnormal alertness, abnormal behavior, coagulopathy, and persistent vomiting. Additional potential predictor variables of TBI were collected based on existing literature (Data Supplement S3).
The primary outcome measure was clinically important brain injury, defined as any traumatic finding identified on CT scan that required hospital admission and neurosurgical follow-up. All brain injuries were considered clinically important unless the patient was neurologically intact (GCS = 15) and had one of the following lesions on CT: solitary contusion of less than 5 mm in diameter, localized subarachnoid blood less than 1 mm thick, smear subdural hematoma less than 4 mm thick, isolated pneumocephalus, or closed depressed skull fracture not through the inner plate.14 Cranial CT scans were interpreted by the clinical radiologists at each site, and all CT findings were retrospectively reviewed by an emergency physician to determine clinically important brain injury on the basis of the independent interpretation by the site radiologists. A single individual determined outcome status for all patients and was masked to all predictor variables at the time of outcome determination.
The secondary outcome measure was the need for neurosurgical intervention, defined as either death within 7 days secondary to TBI or need for any of the following four procedures within 7 days of injury: craniotomy, elevation of skull fracture, intracranial pressure monitoring, or intubation due to TBI.11 In addition, a tertiary outcome was any traumatic finding of the neurocranium on the CT scan (which included ICD 10 diagnostic codes S06.1 to S06.9).
All statistical analysis was performed using STATA Version 11.0 software (StataCorp, College Station, TX). The sensitivity and specificity with 95% confidence intervals (CIs) and negative and positive likelihood ratios (LRs) were calculated for each of the studied decision rules among those subjects eligible for the particular decision rule.
The CCHR is stratified into high-risk and medium-risk criteria, but we tested this rule for any criteria present (i.e. high- and medium-risk criteria). The potential reduction in emergency cranial CT scans was estimated by assuming that if the rule were to be adapted, then a positive result on the rule would be followed by a CT scan and a negative result of the rule would not.
There were 7,131 patients presenting with blunt head trauma during the study period. A total of 696 patients (9.8%) satisfied the CCHR inclusion criteria, 657 patients (9.2%) met the NOC inclusion criteria, and 2,951 patients (41.4%) met the NEXUS-II inclusion criteria. A total of 558 patients (8.2%) were the intersection group of inclusion criteria of all three head CT rules (Figure 1).
Table 2 compares the characteristics of the CCHR group, NOC group, NEXUS-II group, and intersection cohort. Only nine patients (1.3%, 95% CI = 0.6% to 2.4%) in the CCHR group, six patients (0.9%, 95% CI = 0.3% to 2.0%) in the NOC group, and 142 patients (4.8%, 95% CI = 4.1% to 5.6%) in NEXUS-II group underwent neurosurgical intervention, which was defined in CCHR.11 All patients with clinically important brain injury and neurosurgical intervention were identified in the ED without the need for the proxy outcome assessment tool. Among the patients with clinically unimportant brain injury, none required neurosurgical intervention.
|Variables||Inclusion Criteria for CCHR (N = 696)||Inclusion Criteria for NOC (N = 657)||Inclusion Criteria for NEXUS-II (N = 2,951)||Inclusion Criteria for Intersection (N = 588)|
|Age (yr), mean (±SD)||46.1 (±18.9)||42.8 (±20.7)||39.9 (±22.9)||47.0 (±18.9)|
|Mechanism of injury|
|Motor vehicle crashes||289||41.5||280||42.6||863||29.2||220||37.4|
|Injury from sharp material||6||0.9||5||0.8||40||1.4||5||0.9|
|Interval from injury to assessment (hour), median (25%–75% quartile)||1.08 (0.52–3.40)||1.12 (0.50–3.38)||1.08 (0.50–4.22)||1.02 (0.50–3.48)|
|Loss of consciousness||637||91.5||612||93.2||873||29.6||542||92.2|
|Head CT performed||621||89.2||657||100.0||2,951||100.0||588||100.0|
|Any traumatic finding on CT||144||20.7||123||18.7||624||21.1||118||20.1|
|Skull fracture with intracranial injury||40||5.7||38||5.8||195||6.6||35||6.0|
|Focal and diffuse brain injury||23||3.3||18||2.7||119||4.0||18||3.1|
|Clinically important brain injury||120||17.2||99||15.1||576||19.5||98||16.7|
|Elevation of skull fracture||2||0.1||0||0.0||8||0.3||0||0.0|
Table 3 demonstrates the distribution of clinically important brain injury by the CCHR, NOC, and NEXUS-II variables. Several variables had significant association with the presence of traumatic findings on cranial CT scan. Table 4 compares the sensitivity, specificity, and LRs of three head CT rules for their original cohorts for discrimination of outcomes, compared with results from the original articles. Table 5 compares the sensitivity, specificity, and LRs of three head CT rules for the intersection cohort for discrimination of outcomes.
|Criteria of CCHR, NOC, and NEXUS-II||Clinically Important Brain Injury||RR ratio (95% CI)|
|Negative (%)||Positive (%)|
|Variables from CCHR (N = 696)||n = 576||n = 120|
|GCS < 15 at 2 hours postinjury||2.8||15.0||3.44 (2.39–4.94)|
|Suspected skull fracture||1.0||0.8||0.83 (0.13–5.11)|
|Signs of basal skull fracture||3.0||7.5||2.09 (1.20–3.64)|
|Vomiting two or more episodes||4.2||10.8||2.16 (1.35–3.47)|
|Age ≥ 65 years||18.1||37.5||2.20 (1.60–3.04)|
|Dangerous mechanism||19.4||25.0||1.30 (0.90–1.88)|
|Variables from NOC (N = 640)||n = 558||n = 99|
|Drug or alcohol intoxication||25.3||30.3||1.24 (0.84–1.83)|
|Short term memory deficits||30.1||22.2||0.70 (0.45–1.09)|
|Age > 60 years||20.8||37.4||1.97 (1.37–2.83)|
|Trauma above clavicles||26.5||38.4||1.58 (1.09–2.28)|
|Variables from NEXUS-II, (N = 2,951)||n = 2,375||n = 576|
|Evidence of skull fracture||2.6||12.2||2.98 (2.49–3.56)|
|Scalp hematoma||28.3||38.2||1.43 (1.23–1.65)|
|Neurologic deficit||2.4||19.3||3.95 (3.45–4.53)|
|Altered level of alertness||14.2||49.0||3.61 (3.15–4.15)|
|Abnormal behavior||8.7||13.2||1.43 (1.16–1.76)|
|Age ≥ 65 years||13.2||33.4||2.46 (2.13–2.84)|
|Variables from CCHR, NOC, and NEXUS-II for intersection cohort (N = 588)||n = 490||n = 98|
|GCS < 15 at 2 hours postinjury||0.0||0.0||—|
|Suspected skull fracture||3.9||6.1||1.47 (0.71–3.02)|
|Signs of basal skull fracture||3.1||6.1||1.76 (0.87–3.55)|
|Vomiting of two or more episodes||3.7||11.2||2.44 (1.47–4.03)|
|Age ≥ 65 years||18.4||35.7||2.06 (1.43–2.96)|
|Dangerous mechanism||20.4||26.5||1.32 (0.89–1.98)|
|Drug or alcohol intoxication||27.8||31.6||1.17 (0.79–1.72)|
|Age > 60 years||22.7||42.9||2.13 (1.49–3.04)|
|Trauma above clavicles||27.6||37.8||1.47 (1.02–2.12)|
|Altered level of alertness||30.6||30.0||0.96 (0.65–1.43)|
|Abnormal behavior||16.7||21.4||1.28 (0.83–1.98)|
|%||95% CI||%||95% CI|
|Primary outcome: clinically important brain injury|
|Secondary outcome: neurosurgical intervention|
|Tertiary outcome: any traumatic finding on CT|
|%||95% CI||%||95% CI|
|Primary outcome: clinically important brain injury|
|Secondary outcome: neurosurgical intervention|
|Tertiary outcome: any traumatic finding on CT|
The potential reduction in emergency CT scans by using these decision rules would have been higher with the adapted NEXUS-II rule (39.6%, 95% CI = 37.8% to 41.4%) than with the adapted CCHR rule (27.0%, 95% CI = 23.7% to 30.3%) or NOC rule (20.2%, 95% CI = 17.2% to 23.3%).
The CCHR, NOC, and NEXUS-II are the most widely used decision rules for patients with blunt head trauma. We followed the inclusion and exclusion criteria as described in each of the three studies.8,11,12 These differences make comparisons between decision rules somewhat difficult. NEXUS-II included all patients who underwent cranial CT scanning regardless of the patients’ GCS scores. In comparison, the CCHR criteria include patients with GCS scores of 13–15, and the NOC criteria included only those patients with a GCS score of 15, as determined by a physician on the patient’s arrival at the ED (Table 1). Thus, the population included to compare the NEXUS-II rule was much larger (n = 2,951) than the populations to compare the NOC and CCHR rules, where the inclusion criteria are more restrictive (patients with lower GCS scores were not included). The inclusion of patients undergoing cranial CT scanning regardless of GCS score likely elevates the sensitivity of the NEXUS-II rule compared to the CCHR and NOC rules.
We found all three rules to have a lower sensitivity for clinically important brain injury than previously reported when the rules were applied to their original inclusion cohorts. As previously reported, the CCHR and the NOC rules identified all patients requiring neurosurgery; however, the NEXUS-II criteria failed to identify some who required neurosurgery for their original inclusion cohort. The differences in inclusion criteria between the three decision rules result in more patients undergoing neurosurgery in the NEXUS-II group (the other rules have a GCS inclusion criteria, such that lower GCS scores are not included). The smaller numbers of patients with secondary outcomes in the CCHR and NOC groups limit the power to detect meaningful differences. As a result, the 95% CIs for the three rules overlap, and the negative LRs are less than 0.2, suggesting no statistical difference in their ability to detect this outcome, although the NEXUS-II rule did not identify some patients undergoing neurosurgery. All three head CT rules identified all patients requiring neurosurgery when the rules were applied to the intersection cohort.
The CCHR, NOC, and NEXUS-II have been externally compared in several studies, including in countries outside North America. For example, Smits et al.15 prospectively applied the CCHR and the NOC to 3,181 patients in the Netherlands. The sensitivity and specificity for clinically important brain injury were 87.2 and 37.3% for the CCHR, and 99.2 and 3.1%, for NOC.15 Stiell et al.16 applied the CCHR and NOC to 2,707 patients in Canada and reported that the sensitivity and specificity for clinically important brain injury were 100 and 50.6% for CCHR and 100 and 12.7% for NOC. In the current study, the CCHR sensitivity for clinically important brain injury was much lower than that of previously published studies. However, the sensitivities of the NOC and NEXUS-II criteria were comparable to the prior studies. Compared to the report by Stiell et al.16 the current study demonstrated different rates for high risk variables, including high prevalence of headache (a NOC criteria not found in the CCHR) and altered mental status (a NEXUS-II criteria also not present in the CCHR) and lower prevalence rates of CCHR variables including open or depressed skull fracture, signs of basilar skull fracture, and vomiting two or more times. These differences may be responsible for the difference in sensitivity between this study and the CCHR study.
In this study, the percentage of patients with blunt head trauma who underwent cranial CT examination was about 40%. This rate appears artificially low, as we enrolled all patients with any head trauma regardless of how minor the injury. However, the percentage of patients in the CCHR group who underwent a CT examination was about 90%. This rate is higher compared with that previously reported. The NEXUS-II cohort included all patients who underwent cranial CT scanning regardless of GCS score. Thus, the population included to compare the NEXUS-II rule was much larger (n = 2,951) than the population used to compare the NOC and CCHR rules, where the inclusion criteria are more restrictive (patients with lower GCS scores were not included). The types of neurosurgical interventions that patients received are shown in Table 2, but there was no statistical difference between the patients undergoing neurosurgical intervention in any of the three groups.
Numerous national and international guidelines regarding the use of cranial CT in patients with a minor head injury have been published. Use of guidelines that recommend the restrictive use of CT in patients with minor head injury led to a reduced number of CT scans and radiation doses.17 In addition, selective CT utilization in accordance with the CCHR could lead to substantial U.S. cost savings (in the range of $120 million/year).18 However, evidence suggests no benefit in life expectancy and expected quality-adjusted life-years between a strategy of liberal cranial CT use and a selective CT strategy.19 Furthermore, a British study by Boyle et al.20 following implementation of the CCHR showed an increased utilization of cranial CT scanning. Furthermore, implementing the National Institute for Clinical Excellence guidelines, which are based on the CCHR, also led to increased CT scans and hospital admissions for observation.21 In this study, the estimated potential reductions in emergency CT scans by using these decision rules were 27.0% (CCHR), 20.2% (NOC), and 39.6% (NEXUS-II). This conflict accounts for different rates of CT scan utilization between countries. For example, cranial CT scanning was more frequently performed in Korea compared to Canada (89.2% vs. 67.0%) for the minor head injury patients who met CCHR inclusion criteria.11
The study focused only on the three widely disseminated clinical decision rules that are published in English but did not study smaller decision rules or any rules published in non-English journals. Perhaps another rule has better test characteristics. Although this was a multicenter study enrolling a large number of patients with blunt head trauma, the sample of patients with the CCHR and NOC rules who underwent neurosurgery was small, and the CIs around the sensitivity for neurosurgery are wide. However, our results are in line with prior studies demonstrating 100% sensitivity for these rules for this outcome. The study was observational. Any practical application of decision rules in real life might be limited by the individual attitude of the physician, cultural aspects of patient care, and bias due to the medical care system.
For clinically important brain injury, the sensitivities of previously derived cranial CT rules were much lower than previously reported, while the specificities were comparable to those reported in the initial studies of the rules. Despite the lower sensitivities, the Canadian CT Head Rule and New Orleans Criteria rules identified all patients requiring neurosurgery. The National Emergency X-Ray Utilization Study-II rule demonstrated the highest theoretical reduction rate for CT scans compared to other rules, but it failed to identify some patients undergoing neurosurgery for their original inclusion cohort.
- 2National Hospital Ambulatory Medical Care Survey: 2000 emergency department summary. Adv Data. 2002; 327:1–27., .
- 13WHO-ICECI Coordination and Maintenance Group. Testing ICECI: Review and Filed Testing. Amsterdam: Consumer Safety Institute; September 2004. Available at: http://www.rivm.nl/who-fic/ICECI/ICECI_1-2_2004July.pdf. Accessed Mar 28, 2011.
- 14Obtaining consensus for the definition of “clinically important” brain injury in the CCC Study [abstract]. Acad Emerg Med. 2000; 7:572., , , et al.
Data Supplement S1. Comparison of Canadian CT Head Rule (CCHR), New Orleans Criteria (NOC), and NEXUS-II.
Data Supplement S2. The demographics of each hospital site.
Data Supplement S3. The injury surveillance and in-depth surveillance registry of the participating emergency department.
|ACEM_1094_sm_datasupplements1.pdf||42K||Supporting info item|
|ACEM_1094_sm_datasupplements2.pdf||41K||Supporting info item|
|ACEM_1094_sm_datasupplements3.pdf||227K||Supporting info item|
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