We compare the predictive accuracy of emergency physicians' unstructured clinical judgment to the Canadian C-Spine rule.
This prospective multicenter cohort study was conducted at 10 Canadian urban academic emergency departments. Included in the study were alert, stable, adult patients with a Glasgow Coma Scale score of 15 and trauma to the head or neck. This was a substudy of the Canadian C-Spine and CT Head Study. Eligible patients were prospectively evaluated before radiography. Physicians estimated the probability of unstable cervical spine injury from 0% to 100% according to clinical judgment alone and filled out a data form. Interobserver assessments were done when feasible. Patients underwent cervical spine radiography or follow-up to determine clinically important cervical spine injuries. Analyses included comparison of areas under the receiver operating characteristic (ROC) curve with 95% confidence intervals (CIs) and the kappa coefficient.
During 18 months, 6265 patients were enrolled. The mean age was 36.6 years (range 16 to 97 years), and 50.1% were men. Sixty-four (1%) patients had a clinically important injury. The physicians' kappa for a 0% predicted probability of injury was 0.46 (95% CI 0.28 to 0.65). The respective areas under the ROC curve for predicting cervical spine injury were 0.85 (95% CI 0.80 to 0.89) for physician judgment and 0.91 (95% CI 0.89 to 0.92) for the Canadian C-Spine rule (P
Comment In: Ann Emerg Med. 2004 Jun;43(6):789-90; author reply 790-115259167
Comment In: Ann Emerg Med. 2003 Sep;42(3):403-412944894
Comment In: Ann Emerg Med. 2004 Jun;43(6):78815259165
Comment In: Ann Emerg Med. 2004 Jun;43(6):788-915259166
The Canadian C-Spine (cervical-spine) Rule (CCR) and the National Emergency X-Radiography Utilization Study (NEXUS) Low-Risk Criteria (NLC) are decision rules to guide the use of cervical-spine radiography in patients with trauma. It is unclear how the two decision rules compare in terms of clinical performance.
We conducted a prospective cohort study in nine Canadian emergency departments comparing the CCR and NLC as applied to alert patients with trauma who were in stable condition. The CCR and NLC were interpreted by 394 physicians for patients before radiography.
Among the 8283 patients, 169 (2.0 percent) had clinically important cervical-spine injuries. In 845 (10.2 percent) of the patients, physicians did not evaluate range of motion as required by the CCR algorithm. In analyses that excluded these indeterminate cases, the CCR was more sensitive than the NLC (99.4 percent vs. 90.7 percent, P
Current use of cranial computed tomography (CT) for minor head injury is increasing rapidly, highly variable, and inefficient. The Canadian CT Head Rule (CCHR) and New Orleans Criteria (NOC) are previously developed clinical decision rules to guide CT use for patients with minor head injury and with Glasgow Coma Scale (GCS) scores of 13 to 15 for the CCHR and a score of 15 for the NOC. However, uncertainty about the clinical performance of these rules exists.
To compare the clinical performance of these 2 decision rules for detecting the need for neurosurgical intervention and clinically important brain injury.
In a prospective cohort study (June 2000-December 2002) that included 9 emergency departments in large Canadian community and university hospitals, the CCHR was evaluated in a convenience sample of 2707 adults who presented to the emergency department with blunt head trauma resulting in witnessed loss of consciousness, disorientation, or definite amnesia and a GCS score of 13 to 15. The CCHR and NOC were compared in a subgroup of 1822 adults with minor head injury and GCS score of 15.
Neurosurgical intervention and clinically important brain injury evaluated by CT and a structured follow-up telephone interview.
Among 1822 patients with GCS score of 15, 8 (0.4%) required neurosurgical intervention and 97 (5.3%) had clinically important brain injury. The NOC and the CCHR both had 100% sensitivity but the CCHR was more specific (76.3% vs 12.1%, P
Previous studies have indicated that the suboptimal performance of the San Francisco Syncope Rule (SFSR) is likely due to the misclassification of the "abnormal electrocardiogram (ECG)" variable. We sought to identify specific emergency department (ED) ECG and cardiac monitor abnormalities that better predict cardiac outcomes within 30 days in adult ED syncope patients.
This health records review included patients 16 years or older with syncope and excluded patients with ongoing altered mental status, alcohol or illicit drug use, seizure, head injury leading to loss of consciousness, or severe trauma requiring admission. We collected patient characteristics, 22 ECG variables, cardiac monitoring abnormalities, SFSR "abnormal ECG" criteria, and outcome (death, myocardial infarction, arrhythmias, or cardiac procedures) data. Recursive partitioning was used to develop the "Ottawa Electrocardiographic Criteria."
Among 505 included patient visits, 27 (5.3%) had serious cardiac outcomes. We found that patients were at risk for cardiac outcomes within 30 days if any of the following were present: second-degree Mobitz type 2 or third-degree atrioventricular (AV) block, bundle branch block with first-degree AV block, right bundle branch with left anterior or posterior fascicular block, new ischemic changes, nonsinus rhythm, left axis deviation, or ED cardiac monitor abnormalities. The sensitivity and specificity of the Ottawa Electrocardiographic Criteria were 96% (95% CI 80-100) and 76% (95% CI 75-76), respectively.
We successfully identified specific ED ECG and cardiac monitor abnormalities, which we termed the Ottawa Electrocardiographic Criteria, that predict serious cardiac outcomes in adult ED syncope patients. Further studies are required to identify which adult ED syncope patients require cardiac monitoring in the ED and the optimal duration of monitoring and to confirm the accuracy of these criteria.
Syncope is a common disposition challenge for emergency physicians. Among the risk-stratification instruments available, only the San Francisco Syncope Rule is rigorously developed. We evaluate its performance in Canadian emergency department (ED) syncope patients.
This retrospective review included patients aged 16 years or older who fulfilled the definition of syncope (transient loss of consciousness with complete recovery) and presented to a tertiary care ED during an 18-month period. We excluded patients with ongoing altered mental status, alcohol/illicit drug use, seizure, and head and severe trauma. Patient characteristics, 5 predictors for the rule (history of congestive heart failure, hematocrit level
Comment In: Ann Emerg Med. 2011 Jan;57(1):72-3; author reply 7320828875
To compare the predictive accuracy of the Revised Trauma Score (RTS), the Glasgow Coma Scale (GCS), and their components in blunt trauma patients.
This multicenter prospective cohort study was conducted in 20 communities as part of the Ontario Prehospital Advanced Life Support (OPALS) Study. It included adult trauma patients with Injury Severity Scores >12. The assessments made by trauma team leaders for the RTS, GCS, and their subscales were analyzed: 1) receiver operating characteristic (ROC) curve areas and Kendall's tau c correlation coefficient (Tc) for survival to hospital discharge, 2) Mann-Whitney U test and Tc correlations for intensive care unit admission, and 3) Spearman correlations with the disability measure Glasgow Outcome Scale.
The authors analyzed data from 795 blunt trauma patients with these characteristics: median age of 40 years, 70% male, and 18% mortality. The scores that best predicted survival were the RTS (ROC = 0.83, Tc = 0.39), the GCS (ROC = 0.82, Tc = 0.38), the motor component of the GCS (ROC = 0.81, Tc = 0.37), and the verbal component of the GCS (ROC = 0.81, Tc = 0.36). Only scores for the RTS (p = 0.03), the GCS (p = 0.02), and the motor component of the GCS (p = 0.03) showed a significant association with admission to the intensive care unit. The associations with disability were weak in all scores.
The initial emergency department motor score showed the highest predictive validity among all of the other components. These results suggest its validity for blunt trauma triage when compared with the GCS or RTS.
Clinical decision rules can benefit clinicians, patients, and health systems, but they involve considerable up-front development costs and must be acceptable to the target audience. No existing instrument measures the acceptability of a rule. The current study validated such an instrument.
The authors administered the Ottawa Acceptability of Decision Rules Instrument (OADRI) via postal survey to emergency physicians from 4 regions (Australasia, Canada, United Kingdom, and United States), in the context of 2 recently developed rules, the Canadian C-Spine Rule (C-Spine) and the Canadian CT Head Rule (CT-Head). Construct validity of the 12-item instrument was evaluated by hypothesis testing.
As predicted by a priori hypotheses, OADRI scores were 1) higher among rule users than nonusers, 2) higher among those using the rule ''all of the time'' v. ''most of the time'' v. ''some of the time,'' and 3) higher among rule nonusers who would consider using a rule v. those who would not. We also examined explicit reasons given by respondents who said they would not use these rules. Items in the OADRI accounted for 85.5% (C- Spine) and 90.2% (CT-Head) of the reasons given for not considering a rule acceptable.
The OADRI is a simple, 12-item instrument that evaluates rule acceptability among clinicians. Potential uses include comparing multiple ''protorules'' during development, examining acceptability of a rule to a new audience prior to implementation, indicating barriers to rule use addressable by knowledge translation interventions, and potentially serving as a proxy measure for future rule use.
Out-of-hospital hypotension may signify need for intensive resuscitation and rapid diagnosis on emergency department (ED) arrival. We hypothesized that nontraumatic out-of-hospital hypotension confers risk of inhospital mortality.
This was a multicenter study of ambulance-transported, nontrauma, non-cardiopulmonary resuscitation patients conducted at 2 venues: (1) a cross-sectional risk assessment study of high-priority medical transports at a US metropolitan county; and (2) a Canadian prospective multicenter cohort study of patients with respiratory distress. Data at both venues were extracted from prospectively recorded, standardized run sheets by either a physician or a paramedic. Data extraction and analysis at each venue were conducted independently. Exposures to hypotension were defined as age older than 17 years old, systolic blood pressure less than 100 mm Hg during transport, and 1 or more of 10 predefined symptoms of circulatory insufficiency. Nonexposures to hypotension had the same definition as exposures, except the systolic blood pressure had to be more than 100 mm Hg during the entire out-of-hospital transport. The main outcome variable was inhospital mortality.
At venue 1, of 3,128 transports, 395 (13%) exposures and 395 nonexposures were identified. Inhospital mortality of exposures was 26% versus 8% for nonexposures (adjusted odds ratio [OR] 4.6; 95% confidence interval [CI] 2.0 to 5.9). At venue 2, of 7,679 transports, 532 exposures (7%) and 7,147 nonexposures were identified. Out-of-hospital exposure to hypotension conferred a mortality rate of 32% versus 11% for nonexposures (OR 3.0; 95% CI 2.4 to 3.7), representing a sensitivity of 18% and a specificity of 95%.
The inhospital mortality rate after out-of-hospital, nontraumatic hypotension is high and reproducible. Future research should focus on ED clinical protocols to ensure appropriate resuscitation and investigation of etiology of out-of-hospital hypotension.
We designed the Canadian C-Spine Rule for the clinical clearance of the cervical spine, without need for diagnostic imaging, in alert and stable trauma patients. Emergency physicians previously validated the Canadian C-Spine Rule in 8,283 patients. This study prospectively evaluates the performance characteristics, reliability, and clinical sensibility of the Canadian C-Spine Rule when used by paramedics in the out-of-hospital setting.
We conducted this prospective cohort study in 7 Canadian regions and involved alert (Glasgow Coma Scale score 15) and stable adult trauma patients at risk for neck injury. Advanced and basic care paramedics interpreted the Canadian C-Spine Rule status for all patients, who then underwent immobilization and assessment in the emergency department to determine the outcome, clinically important cervical spine injury.
The 1,949 patients enrolled had these characteristics: median age 39.0 years (interquartile range 26 to 52 years), female patients 50.8%, motor vehicle crash 62.5%, fall 19.9%, admitted to the hospital 10.8%, clinically important cervical spine injury 0.6%, unimportant injury 0.3%, and internal fixation 0.3%. The paramedics classified patients for 12 important injuries with sensitivity 100% (95% confidence interval [CI] 74% to 100%) and specificity 37.7% (95% CI 36% to 40%). The kappa value for paramedic interpretation of the Canadian C-Spine Rule (n=155) was 0.93 (95% CI 0.87 to 0.99). Paramedics conservatively misinterpreted the rule in 320 (16.4%) patients and were comfortable applying the rule in 1,594 (81.7%). Seven hundred thirty-one (37.7%) out-of-hospital immobilizations could have been avoided with the Canadian C-Spine Rule.
This study found that paramedics can apply the Canadian C-Spine Rule reliably, without missing any important cervical spine injuries. The adoption of the Canadian C-Spine Rule by paramedics could significantly reduce the number of out-of-hospital cervical spine immobilizations.
Comment In: Ann Emerg Med. 2010 Apr;55(4):380-920346840
Comment In: Ann Emerg Med. 2009 Nov;54(5):672-319853780
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.
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.
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.
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).
Cites: Adv Data. 1994 Mar 2;(245):1-1210132568
Cites: JAMA. 1994 Mar 16;271(11):827-328114236
Cites: CMAJ. 1995 Nov 15;153(10):1423-317585368
Cites: JAMA. 1997 Feb 12;277(6):488-949020274
Cites: Ann Emerg Med. 1997 Jul;30(1):14-229209219
Cites: Stat Med. 1997 Sep 30;16(18):2063-799308132
Cites: JAMA. 1997 Dec 17;278(23):2075-99403421
Cites: BMJ. 1998 Aug 15;317(7156):465-89703533
Cites: Ann Emerg Med. 1999 Apr;33(4):437-4710092723
Cites: JAMA. 2005 Sep 28;294(12):1511-816189364
Cites: Ann Intern Med. 2006 Feb 7;144(3):201-916461965