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1.  National survey of physicians to determine the effect of unconditional incentives on response rates of physician postal surveys 
BMJ Open  2015;5(2):e007166.
Physicians are a commonly targeted group in health research surveys, but their response rates are often relatively low. The goal of this paper was to evaluate the effect of unconditional incentives in the form of a coffee card on physician postal survey response rates.
Following 13 key informant interviews and eight cognitive interviews a survey questionnaire was developed.
A random sample of 534 physicians, stratified by physician group (geriatricians, family physicians, emergency physicians) was selected from a national medical directory.
Using computer generated random numbers; half of the physicians in each stratum were allocated to receive a coffee card to a popular national coffee chain together with the first survey mailout.
The intervention was a $10 Tim Hortons gift card given to half of the physicians who were randomly allocated to receive the incentive.
265 (57.0%) physicians completed the survey. The response rate was significantly higher in the group allocated to receive the incentive (62.7% vs 51.3% in the control group; p=0.01).
Our results indicate that an unconditional incentive in the form of a coffee gift card can substantially improve physician response rates. Future research can look at the effect of varying amounts of cash on the gift cards on response rates.
PMCID: PMC4336460  PMID: 25694460
2.  Differentiation between traumatic tap and aneurysmal subarachnoid hemorrhage: prospective cohort study 
Objectives To describe the findings in cerebrospinal fluid from patients with acute headache that could distinguish subarachnoid hemorrhage from the effects of a traumatic lumbar puncture.
Design A substudy of a prospective multicenter cohort study.
Setting 12 Canadian academic emergency departments, from November 2000 to December 2009.
Participants Alert patients aged over 15 with an acute non-traumatic headache who underwent lumbar puncture to rule out subarachnoid hemorrhage.
Main outcome measure Aneurysmal subarachnoid hemorrhage requiring intervention or resulting in death.
Results Of the 1739 patients enrolled, 641 (36.9%) had abnormal results on cerebrospinal fluid analysis with >1×106/L red blood cells in the final tube of cerebrospinal fluid and/or xanthochromia in one or more tubes. There were 15 (0.9%) patients with aneurysmal subarachnoid hemorrhage based on abnormal results of a lumbar puncture. The presence of fewer than 2000×106/L red blood cells in addition to no xanthochromia excluded the diagnosis of aneurysmal subarachnoid hemorrhage, with a sensitivity of 100% (95% confidence interval 74.7% to 100%) and specificity of 91.2% (88.6% to 93.3%).
Conclusion No xanthochromia and red blood cell count <2000×106/L reasonably excludes the diagnosis of aneurysmal subarachnoid hemorrhage. Most patients with acute headache who meet this cut off will need no further investigations and aneurysmal subarachnoid hemorrhage can be excluded as a cause of their headache.
PMCID: PMC4353280  PMID: 25694274
3.  Prospective validation of the ABCD2 score for patients in the emergency department with transient ischemic attack 
The ABCD2 score (Age, Blood pressure, Clinical features, Duration of symptoms and Diabetes) is used to identify patients having a transient ischemic attack who are at high risk for imminent stroke. However, despite its widespread implementation, the ABCD2 score has not yet been prospectively validated. We assessed the accuracy of the ABCD2 score for predicting stroke at 7 (primary outcome) and 90 days.
This prospective cohort study enrolled adults from eight Canadian emergency departments who had received a diagnosis of transient ischemic attack. Physicians completed data forms with the ABCD2 score before disposition. The outcome criterion, stroke, was established by a treating neurologist or by an Adjudication Committee. We calculated the sensitivity and specificity for predicting stroke 7 and 90 days after visiting the emergency department using the original “high-risk” cutpoint of an ABCD2 score of more than 5, and the American Heart Association recommendation of a score of more than 2.
We enrolled 2056 patients (mean age 68.0 yr, 1046 (50.9%) women) who had a rate of stroke of 1.8% at 7 days and 3.2% at 90 days. An ABCD2 score of more than 5 had a sensitivity of 31.6% (95% confidence interval [CI] 19.1–47.5) for stroke at 7 days and 29.2% (95% CI 19.6–41.2) for stroke at 90 days. An ABCD2 score of more than 2 resulted in sensitivity of 94.7% (95% CI 82.7–98.5) for stroke at 7 days with a specificity of 12.5% (95% CI 11.2–14.1). The accuracy of the ABCD2 score as calculated by either the enrolling physician (area under the curve 0.56; 95% CI 0.47–0.65) or the coordinating centre (area under the curve 0.65; 95% CI 0.57–0.73) was poor.
This multicentre prospective study involving patients in emergency departments with transient ischemic attack found the ABCD2 score to be inaccurate, at any cut-point, as a predictor of imminent stroke. Furthermore, the ABCD2 score of more than 2 that is recommended by the American Heart Association is nonspecific.
PMCID: PMC3134721  PMID: 21646462
4.  Acute Isolated Dysarthria Is Associated with a High Risk of Stroke 
Cerebrovascular Diseases Extra  2014;4(2):182-185.
Isolated dysarthria is an uncommon presentation of transient ischemic attack (TIA)/minor stroke and has a broad differential diagnosis. There is little information in the literature about how often this presentation is confirmed to be a TIA/stroke, and therefore there is debate about the risk of subsequent vascular events. Given the uncertain prognosis, it is unclear how to best manage patients presenting to the emergency department (ED) with isolated dysarthria. The objective of this study was to prospectively identify and follow a cohort of patients presenting to EDs with isolated dysarthria in order to explore their natural history and risk of recurrent cerebrovascular events. Specifically, we sought to determine early outcomes of individuals with this nonspecific and atypical presentation in order to appropriately expedite their management.
Patients with isolated dysarthria having presented to 8 Canadian EDs between October 2006 and April 2009 were analyzed as part of a prospective multicenter cohort study of patients with acute neurological symptoms as assessed by emergency physicians. The study inclusion criteria were age ≥18 years, a normal level of consciousness, and a symptom onset <1 week prior to presentation without an established nonvascular etiology. The primary outcome was a subsequent stroke within 90 days of the index visit. The secondary outcomes were the rate of TIA, myocardial infarction, and death. Isolated dysarthria was defined as slurring with imprecise articulation but without evidence of language dysfunction. The overall rate of stroke in this cohort was compared with that predicted by the median ABCD2 score for this group.
Between 2006 and 2009, 1,528 patients were enrolled and had a 90-day follow-up. Of these, 43 patients presented with isolated acute-onset dysarthria (2.8%). Recurrent stroke occurred in 6/43 (14.0%) within 90 days of enrollment. The predicted maximal 90-day stroke rate was 9.8% (based on a median ABCD2 score of 5 for the isolated dysarthria cohort). After adjusting for covariates, isolated dysarthria independently predicted stroke within 90 days (aOR: 3.96; 95% CI: 1.3-11.9; p = 0.014).
The isolated dysarthria cohort carried a recurrent stroke risk comparable to that predicted by the median ABCD2 scores. Although isolated dysarthria is a nonspecific and uncommon clinical presentation of TIA, these findings support the need to view it first and foremost as a vascular presentation until proven otherwise and to manage such patients as if they were at high risk of stroke in accordance with established high-risk TIA guidelines.
PMCID: PMC4176400  PMID: 25298772
Stroke; Transient ischemic attack; Risk stratification; Outcome; Dysarthria
5.  Clinical characteristics associated with adverse events in patients with exacerbation of chronic obstructive pulmonary disease: a prospective cohort study 
To assist physicians with difficult decisions about hospital admission for patients with acute exacerbation of chronic obstructive pulmonary disease (COPD) presenting in the emergency department, we sought to identify clinical characteristics associated with serious adverse events.
We conducted this prospective cohort study in 6 large Canadian academic emergency departments. Patients were assessed for standardized clinical variables and then followed for serious adverse events, defined as death, intubation, admission to a monitored unit or new visit to the emergency department requiring admission.
We enrolled 945 patients, of whom 354 (37.5%) were admitted to hospital. Of 74 (7.8%) patients with a subsequent serious adverse event, 36 (49%) had not been admitted after the initial emergency visit. Multivariable modelling identified 5 variables that were independently associated with adverse events: prior intubation, initial heart rate ≥ 110/minute, being too ill to do a walk test, hemoglobin < 100 g/L and urea ≥ 12 mmol/L. A preliminary risk scale incorporating these and 5 other clinical variables produced risk categories ranging from 2.2% for a score of 0 to 91.4% for a score of 10. Using a risk score of 2 or higher as a threshold for admission would capture all patients with a predicted risk of adverse events of 7.2% or higher, while only slightly increasing admission rates, from 37.5% to 43.2%.
In Canada, many patients with COPD suffer a serious adverse event or death after being discharged home from the emergency department. We identified high-risk characteristics and developed a preliminary risk scale that, once validated, could be used to stratify the likelihood of poor outcomes and to enable rational and safe admission decisions.
PMCID: PMC3971051  PMID: 24549125
6.  Sensitivity of computed tomography performed within six hours of onset of headache for diagnosis of subarachnoid haemorrhage: prospective cohort study 
Objective To measure the sensitivity of modern third generation computed tomography in emergency patients being evaluated for possible subarachnoid haemorrhage, especially when carried out within six hours of headache onset.
Design Prospective cohort study.
Setting 11 tertiary care emergency departments across Canada, 2000-9.
Participants Neurologically intact adults with a new acute headache peaking in intensity within one hour of onset in whom a computed tomography was ordered by the treating physician to rule out subarachnoid haemorrhage.
Main outcome measures Subarachnoid haemorrhage was defined by any of subarachnoid blood on computed tomography, xanthochromia in cerebrospinal fluid, or any red blood cells in final tube of cerebrospinal fluid collected with positive results on cerebral angiography.
Results Of the 3132 patients enrolled (mean age 45.1, 2571 (82.1%) with worst headache ever), 240 had subarachnoid haemorrhage (7.7%). The sensitivity of computed tomography overall for subarachnoid haemorrhage was 92.9% (95% confidence interval 89.0% to 95.5%), the specificity was 100% (99.9% to 100%), the negative predictive value was 99.4% (99.1% to 99.6%), and the positive predictive value was 100% (98.3% to 100%). For the 953 patients scanned within six hours of headache onset, all 121 patients with subarachnoid haemorrhage were identified by computed tomography, yielding a sensitivity of 100% (97.0% to 100.0%), specificity of 100% (99.5% to 100%), negative predictive value of 100% (99.5% to 100%), and positive predictive value of 100% (96.9% to 100%).
Conclusion Modern third generation computed tomography is extremely sensitive in identifying subarachnoid haemorrhage when it is carried out within six hours of headache onset and interpreted by a qualified radiologist.
PMCID: PMC3138338  PMID: 21768192
7.  High risk clinical characteristics for subarachnoid haemorrhage in patients with acute headache: prospective cohort study 
Objective To identify high risk clinical characteristics for subarachnoid haemorrhage in neurologically intact patients with headache.
Design Multicentre prospective cohort study over five years.
Setting Six university affiliated tertiary care teaching hospitals in Canada. Data collected from November 2000 until November 2005.
Participants Neurologically intact adults with a non-traumatic headache peaking within an hour.
Main outcome measures Subarachnoid haemorrhage, as defined by any of subarachnoid haemorrhage on computed tomography of the head, xanthochromia in the cerebrospinal fluid, or red blood cells in the final sample of cerebrospinal fluid with positive results on angiography. Physicians completed data collection forms before investigations.
Results In the 1999 patients enrolled there were 130 cases of subarachnoid haemorrhage. Mean (range) age was 43.4 (16-93), 1207 (60.4%) were women, and 1546 (78.5%) reported that it was the worst headache of their life. Thirteen of the variables collected on history and three on examination were reliable and associated with subarachnoid haemorrhage. We used recursive partitioning with different combinations of these variables to create three clinical decisions rules. All had 100% (95% confidence interval 97.1% to 100.0%) sensitivity with specificities from 28.4% to 38.8%. Use of any one of these rules would have lowered rates of investigation (computed tomography, lumbar puncture, or both) from the current 82.9% to between 63.7% and 73.5%.
Conclusion Clinical characteristics can be predictive for subarachnoid haemorrhage. Practical and sensitive clinical decision rules can be used in patients with a headache peaking within an hour. Further study of these proposed decision rules, including prospective validation, could allow clinicians to be more selective and accurate when investigating patients with headache.
PMCID: PMC2966872  PMID: 21030443
8.  A prospective cluster-randomized trial to implement the Canadian CT Head Rule in emergency departments 
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. ( trial register no. NCT00993252)
PMCID: PMC2950184  PMID: 20732978
9.  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.
PMCID: PMC2770593  PMID: 19875425
10.  Predictors of Positive Chest Radiography in Non-Traumatic Chest Pain in the Emergency Department 
Oman Medical Journal  2009;24(1):22-26.
To determine predictors associated with positive chest x-ray finding in patients presenting with non-traumatic chest pain in the Emergency Department (ED).
Health records, including the final radiology reports of all patients who presented with non-traumatic chest pain and had a chest x-ray performed in an urban Canadian tertiary care ED over four consecutive months were reviewed. Demographic and clinical variables were also extracted. Chest x-ray findings were categorized as normal (either normal or no significant change from previous x-rays) or abnormal. Descriptive statistics were used to describe the data. Multivariable logistic regression was used to determine the association between various predictors and chest x-ray finding (positive/negative).
The 330 study patients had the following characteristics: mean age 58±20 years; female 41% (n=134). Patients’ chief complaints were only chest pain 75% (n=248), chest pain with shortness of breath 12% (n=41), chest pain with palpitation 4% (n=14), chest pain with other complaints 9% (n=28). Chest x-rays were reported as normal or no acute changes in 81% (n=266) of patients, and abnormal in 19% (n=64) of patients. The most common abnormal chest x-ray diagnoses were congestive heart failure (n=28; 8%) and pneumonia (n=17; 5%). Those with abnormal chest x-ray findings were significantly older (71 versus 55 years; p<0.001), had chest pain with shortness of breath (36% versus 11%; p<0.001), had significant past medical history (39% versus 14%; p<0.001), and were also tachypnoic (31% versus 12%; p<0.001).
This study found that patients with non-traumatic chest pain are likely to have a normal chest x-ray if they were young, not tachypnoeic or short of breath, and had no significant past medical history. A larger study is required to confirm these findings.
PMCID: PMC3269614  PMID: 22303504
11.  How do emergency physicians make discharge decisions? 
One of the most important decisions that emergency department (ED) physicians make is patient disposition (admission vs discharge).
To determine how ED physicians perceive their discharge decisions for high-acuity patients and the impact on adverse events (adverse outcomes associated with healthcare management).
We conducted a real-time survey of staff ED physicians discharging consecutive patients from high-acuity areas of a tertiary care ED. We asked open-ended questions about rationale for discharge decisions and use of clinical judgement versus evidence. We searched for 30-day flagged outcomes (deaths, unscheduled admissions, ED or clinic visits). Three trained blinded ED physicians independently reviewed these for adverse events and preventability. We resolved disagreements by consensus. We used descriptive statistics and 95% CIs.
We interviewed 88.9% (32/36) of possible ED physicians for 366 discharge decisions. Respondents were mostly male (71.9%) and experienced (53.1% >10 years). ED physicians stated they used clinical judgement in 87.6% of decisions and evidence in 12.4%. There were 69 flagged outcomes (18.8%) and 10 adverse events (2.7%, 95% CI 1.1 to 4.5%). All adverse events were preventable (1 death, 4 admissions, 5 return ED visits). No significant associations occurred between decision-making rationale and adverse events.
Experienced ED physicians most often relied on clinical acumen rather than evidence-based guidelines when discharging patients from ED high-acuity areas. Neither approach was associated with adverse events. In order to improve the safety of discharge decisions, further research should focus on decision support solutions and feedback interventions.
PMCID: PMC4283689  PMID: 24045050
clinical care; education; emergency care systems

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