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Michael J Schull

Publications and source records attributed to Michael J Schull.

At least 19 recordsLinked to original sources
PubMed2006

The effect of low-complexity patients on emergency department waiting times.

STUDY OBJECTIVE: The extent to which patients presenting to emergency departments (EDs) with minor conditions contribute to delays and crowding is controversial. To test this question, we study the effect of low-complexity ED patients on the waiting times of other patients. METHODS: We obtained administrative records on all ED visits to Ontario hospitals from April 2002 to March 2003. For each ED, we determined the association between the number of new low-complexity patients (defined as ambulatory arrival, low-acuity triage level, and discharged) presenting in each 8-hour interval and the mean ED length of stay and time to first physician contact for medium- and high-complexity patients. Covariates were the number of new high- and medium-complexity patients, mean patient age, sex distribution, hospital teaching status, work shift, weekday/weekend, and total patient-hours. Autoregression modeling was used given correlation in the data. RESULTS: One thousand ninety-five consecutive 8-hour intervals at 110 EDs were analyzed; 4.1 million patient visits occurred, 50.8% of patients were women, and mean age was 38.4 years. Low-, medium-, and high-complexity patients represented 50.9%, 37.1%, and 12% of all patients, respectively. Mean (median) ED length of stay was 6.3 (4.7), 3.9 (2.8), and 2.2 (1.6) hours for high-, medium-, and low-complexity patients, respectively, and mean (median) time to first physician contact was 1.1 (0.7), 1.3 (0.9), and 1.1 (0.8) hours. In adjusted analyses, every 10 low-complexity patients arriving per 8 hours was associated with a 5.4-minute (95% confidence interval [CI] 4.2 to 6.0 minutes) increase in mean length of stay and a 2.1-minute (95% CI 1.8 to 2.4 minutes) increase in mean time to first physician contact for medium- and high-complexity patients. Results were similar regardless of ED volume and teaching status. CONCLUSION: Low-complexity ED patients are associated with a negligible increase in ED length of stay and time to first physician contact for other ED patients. Reducing the number of low-complexity ED patients is unlikely to reduce waiting times for other patients or lessen crowding.

Adult↗
PubMed2006

Surge capacity associated with restrictions on nonurgent hospital utilization and expected admissions during an influenza pandemic: lessons from the Toronto severe acute respiratory syndrome outbreak.

BACKGROUND: Current influenza pandemic models predict a surge in influenza-related hospitalizations in affected jurisdictions. One proposed strategy to increase hospital surge capacity is to restrict elective hospitalizations, yet the degree to which this measure would meet the anticipated is unknown. OBJECTIVES: To compare the reduction in hospitalizations resulting from widespread nonurgent hospital admission restrictions during the Toronto severe acute respiratory syndrome (SARS) outbreak with the expected increase in admissions resulting from an influenza pandemic in Toronto. METHODS: The authors compared the expected influenza-related hospitalizations in the first eight weeks of a mild, moderate, or severe pandemic with the actual reduction in the number of hospital admissions in Toronto, Ontario, during the first eight weeks of the SARS-related restrictions. RESULTS: Influenza modeling for Toronto predicts that there will be 4,819, 8,032, or 11,245 influenza-related admissions in the first eight weeks of a mild, moderate, or severe pandemic, respectively. In the first eight weeks of SARS-related hospital admission restrictions, there were 3,654 fewer hospitalizations than expected in Toronto, representing a modest 12% decrease in the overall admission rate (a reduction of 1.40 admissions per 1,000 population). Therefore, influenza-related admissions could exceed the reduction in admissions resulting from restricted hospital utilization by 1,165 to 7,591 patient admissions, depending on pandemic severity, which corresponds to an excess of 0.44 to 2.91 influenza-related admissions per 1,000 population per eight weeks, and an increase of 4% to 25% in the overall number of admissions, when compared with nonpandemic conditions. CONCLUSIONS: Pandemic modeling for Toronto suggests that influenza-related admissions would exceed the reduction in hospitalizations seen during SARS-related nonurgent hospital admission restrictions, even in a mild pandemic. Sufficient surge capacity in a pandemic will likely require the implementation of other measures, including possibly stricter implementation of hospital utilization restrictions.

Bed Occupancy↗
PubMed2006

The risk of missed diagnosis of acute myocardial infarction associated with emergency department volume.

STUDY OBJECTIVE: Missed diagnosis of acute myocardial infarction is associated with adverse clinical outcomes and more dollars recovered in malpractice suits than any other condition. The rate of missed diagnosis varies between emergency departments (EDs); we hypothesized that it is associated with the volume of acute myocardial infarction patients treated in an ED and that the association can be explained by other hospital characteristics. METHODS: We linked the records of all acute myocardial infarction patients admitted to an Ontario hospital in 2002 to 2003 to their ED visit records in the 7 days preceding admission. Acute myocardial infarctions were defined as missed if the diagnosis on the previous visit matched a list of cardiac symptoms and illnesses. We assessed whether annual volume of admitted acute myocardial infarction patients treated in the ED (grouped as 0 to 49; 50 to 99; 100 to 199; 200 to 299; and > or = 300) was associated with missed acute myocardial infarction, adjusting for age, sex, teaching hospital status, and acute myocardial infarction severity. In a secondary analysis, we used data from a survey of Ontario EDs to assess whether hospital characteristics (triage practices, use of diagnostic tests, and consultant availability) explained the volume association. RESULTS: Of 19,663 acute myocardial infarction patients, mean age (68.3 years), sex (63% men), and predicted 1-year mortality (mean 0.21; SD 0.18) were similar across volume groups. The rate of missed acute myocardial infarction was 2.1% (95% confidence interval [CI] 1.9% to 2.3%) and varied from 0% to 29% across EDs. Compared with very high-volume EDs, the adjusted odds ratio of missed acute myocardial infarction was 2.0 in very low- (95% CI 1.5 to 2.7) and 1.6 in low- (95% CI 1.1 to 2.3) volume EDs. Consultant availability partially explained the volume effect. CONCLUSION: Lower-volume EDs have up to 2-fold higher odds of missed acute myocardial infarctions compared with highest-volume ones after controlling for patient factors. Many current technologies designed to increase diagnostic sensitivity are feasible only in higher-volume centers. Efforts to reduce overall rates of missed acute myocardial infarctions should instead focus on simpler solutions appropriate for lower-volume EDs, such as telemedicine to improve access to consultant expertise.

Adult↗
PubMed2006

Clinical features of head injury patients presenting with a Glasgow Coma Scale score of 15 and who require neurosurgical intervention.

STUDY OBJECTIVE: Emergency physicians are concerned about minor head injury patients who present with a Glasgow Coma Scale (GCS) score of 15 yet require neurosurgical intervention. Our objectives are to determine the accuracy of the Canadian CT Head Rule (CCHR) in this important subset, the prevalence of patients requiring urgent intervention, and their clinical course and possible warning signs. METHODS: We conducted a secondary data analysis of the CCHR study cohorts from 10 hospital emergency departments (EDs). We included head trauma patients with witnessed loss of consciousness, disorientation, or definite amnesia and who presented with an initial GCS score of 15. Records were reviewed and specific variables added to the database. The primary outcome was need for urgent neurosurgical intervention. RESULTS: Among the 4,551 study patients, only 26 (0.6%; 95% confidence interval [CI] 0 to 1.0%) required neurosurgical intervention, and the CCHR identified all 26 cases with 100% sensitivity. Eleven patients required "urgent" craniotomy within 7 days, and of those, 2 patients deteriorated precipitously. These 11 (0.2%; 95% CI 0.1% to 0.3%) cases had additional signs: GCS score decrease within 6 hours (82%), GCS score decrease within 3 hours (73%), confusion (64%), any vomiting (36%), focal temporal blow (36%), restlessness (36%), and severe headache (45%). CONCLUSION: For patients with minor head injury and GCS score of 15, urgent neurosurgical intervention and precipitous deterioration are rare. The CCHR accurately identified all patients requiring neurosurgical intervention. Warning signs that may portend need for urgent intervention include any vomiting, restlessness, any GCS score decrease, severe headache, confusion, and focal temporal blow.

Adolescent↗
PubMed2006

ALARMED: adverse events in low-risk patients with chest pain receiving continuous electrocardiographic monitoring in the emergency department. A pilot study.

OBJECTIVES: Current guidelines suggest that most patients who present to an emergency department (ED) with chest pain should be placed on a continuous electrocardiographic monitoring (CEM) device. We evaluated the utility of CEM in ED patients with chest pain. METHODS: We enrolled stable patients who presented to a single ED with chest pain suspected to be ischemic in origin and who were placed on CEM. Patients were classified according to risk of poor outcome using 3 published stratification tools. Trained observers prospectively recorded number of monitored hours, alarms, changes in management, and monitor-detected adverse events (AEs). The primary outcome measure was the rate of AEs detected by CEM. Secondary outcome measures were the rate of alarms that resulted in a change in management and number of false alarms. RESULTS: We enrolled 72 patients, 56% of whom were categorized as very low-risk by Goldman risk criteria. During 371 monitored hours, we recorded 1762 alarms or 4.7 alarms per monitored hour. There were 11 AEs (0.68%; 95% CI, 0.35%-1.2%), 3 of which resulted in a change in management (0.2%; 95% CI, 0.04%-0.5%). Seven AEs were bradydysrhythmias with a heart rate of 45 or higher; the eighth patient had no change in symptoms and was given atropine for a heart rate of 32. The other 3 AEs were an untreated supraventricular tachycardia, a brief sinus pause that triggered a rate change in intravenous nitroglycerin by the patient's nurse, and a run of premature ventricular contractions after which heparin was administered. None of the 3 patients with a change in management was categorized as the lowest-risk. CONCLUSIONS: Routine CEM in low-risk ED patients with chest pain results in an excessive number of alarms, most of which require no change in management. In these patients, the benefit of CEM may be limited, and given that 99.4% of alarms were false, current CEM technology needs to be improved.

Adult↗
PubMed2005

Cardiovascular health after maternal placental syndromes (CHAMPS): population-based retrospective cohort study.

BACKGROUND: Maternal placental syndromes, including the hypertensive disorders of pregnancy and abruption or infarction of the placenta, probably originate from diseased placental vessels. The syndromes arise most often in women who have metabolic risk factors for cardiovascular disease, including obesity, pre-pregnancy hypertension, diabetes mellitus, and dyslipidaemia. Our aim was to assess the risk of premature vascular disease in women who had had a pregnancy affected by maternal placental syndromes. METHODS: We did a population-based retrospective cohort study in Ontario, Canada, of 1.03 million women who were free from cardiovascular disease before their first documented delivery. We defined the following as maternal placental syndromes: pre-eclampsia, gestational hypertension, placental abruption, and placental infarction. Our primary endpoint was a composite of cardiovascular disease, defined as hospital admission or revascularisation for coronary artery, cerebrovascular, or peripheral artery disease at least 90 days after the delivery discharge date. FINDINGS: The mean (SD) age of participants was 28.2 (5.5) years at the index delivery, and 75 380 (7%) women were diagnosed with a maternal placental syndrome. The incidence of cardiovascular disease was 500 per million person-years in women who had had a maternal placental syndrome compared with 200 per million in women who had not (adjusted hazard ratio [HR] 2.0, 95 CI 1.7-2.2). This risk was higher in the combined presence of a maternal placental syndrome and poor fetal growth (3.1, 2.2-4.5) or a maternal placental syndrome and intrauterine fetal death (4.4, 2.4-7.9), relative to neither. INTERPRETATION: The risk of premature cardiovascular disease is higher after a maternal placental syndrome, especially in the presence of fetal compromise. Affected women should have their blood pressure and weight assessed about 6 months postpartum, and a healthy lifestyle should be emphasised.

Adolescent↗
PubMed2005

Comparison of the Canadian CT Head Rule and the New Orleans Criteria in patients with minor head injury.

CONTEXT: 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. OBJECTIVE: To compare the clinical performance of these 2 decision rules for detecting the need for neurosurgical intervention and clinically important brain injury. DESIGN, SETTING, AND PATIENTS: 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. MAIN OUTCOME MEASURES: Neurosurgical intervention and clinically important brain injury evaluated by CT and a structured follow-up telephone interview. RESULTS: 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<.001) for predicting need for neurosurgical intervention. For clinically important brain injury, the CCHR and the NOC had similar sensitivity (100% vs 100%; 95% confidence interval [CI], 96%-100%) but the CCHR was more specific (50.6% vs 12.7%, P<.001), and would result in lower CT rates (52.1% vs 88.0%, P<.001). The kappa values for physician interpretation of the rules, CCHR vs NOC, were 0.85 vs 0.47. Physicians misinterpreted the rules as not requiring imaging for 4.0% of patients according to CCHR and 5.5% according to NOC (P = .04). Among all 2707 patients with a GCS score of 13 to 15, the CCHR had sensitivities of 100% (95% CI, 91%-100%) for 41 patients requiring neurosurgical intervention and 100% (95% CI, 98%-100%) for 231 patients with clinically important brain injury. CONCLUSION: For patients with minor head injury and GCS score of 15, the CCHR and the NOC have equivalent high sensitivities for need for neurosurgical intervention and clinically important brain injury, but the CCHR has higher specificity for important clinical outcomes than does the NOC, and its use may result in reduced imaging rates.

Adolescent↗
PubMed2005

Can the wrong statistic be bad for health? Improving the reporting of door-to-needle time performance in acute myocardial infarction.

BACKGROUND: Current acute myocardial infarction (AMI) guidelines call for reperfusion to be given to all eligible patients within a set time interval after hospital arrival, yet current hospital performance benchmarks are based on the median door-to-intervention time among treated patients. Our objective is to compare hospital performance rankings when door-to-needle time (DNT) is measured at the current benchmark (median < or = 30 minutes) versus those obtained with more stringent benchmarks common for other AMI treatments. METHODS: A secondary analysis of data from the EFFECT study from 52 small, community and teaching hospitals in Ontario. All Ontario hospital corporations that treated > or = 30 patients with AMI from 1999 to 2001 participated. The charts of approximately 125 patients with AMI per hospital were reviewed; median and 85th percentile DNTs were then calculated for patients with ST-elevation AMI given thrombolysis at each site along with the proportion of patients thrombolysed within the recommended time. Hospitals were then ranked according to each indicator. RESULTS: Data were obtained on 1,578 patients given thrombolytic drugs at 52 hospitals. The median and 85th percentile DNTs were 37 and 82 minutes, respectively; the proportion of patients treated in < or = 30 minutes ranged from 8.5% to 60%. Hospitals that achieved a median DNT of < or = 30 minutes treated 40% to 50% of their patients outside that time frame. The ranks of the top 15 median DNT hospitals changed substantially when re-ranked according to the 85th percentile (average change in rank -16, range +6 to -40). If DNT improved such that a 30-minute median target was achieved, the estimated reduction for the average patient would be 13 minutes versus a 43-minute reduction if the 85th percentile target was achieved. CONCLUSION: Hospitals that achieve a 30-minute median DNT benchmark still treat 40% to 50% of their patients outside the recommended time, which is not consistent with current AMI treatment guidelines. Door-to-needle time for the average patient would be up to 43 minutes faster if the DNT target was achieved at the 85th percentile.

Benchmarking↗
PubMed2005

Metabolic syndrome and the risk of placental dysfunction.

BACKGROUND: Placental dysfunction (PD), which may manifest partly as the hypertensive disorders of pregnancy and abruption or infarction of the placenta, occurs more commonly in women with obesity, chronic hypertension, diabetes mellitus, and dyslipidemia-each a major feature of the metabolic syndrome. However, the relationship between the metabolic syndrome and the future risk of PD or fetal demise is unknown. METHODS: We completed a retrospective cohort study of 1.03 million women who had a first documented delivery in the province of Ontario between 1990 and 2002. Using linked administrative databases, we categorized women as having zero, one, two, or three to four features of the metabolic syndrome up to 24 months before their index delivery hospitalization. Women were considered to have placental dysfunction if they had a diagnosis of preeclampsia, gestational hypertension, placental abruption, or placental infarction during their first hospitalization for delivery in the period of study. RESULTS: At the time of delivery, 75 380 women (7.3%) were diagnosed as having PD. There was a progressive increase in the risk of PD in women with one (adjusted odds ratio [OR] 3.1; 95% confidence interval [CI] 3.0-3.1), two (OR 5.5; 95% CI 5.2-5.8), or three to four (OR 7.7; 95% CI 6.7-8.9) features of the metabolic syndrome, compared with none. A similar gradient effect was seen for the combined outcome of PD with poor fetal growth, or of PD with concomitant fetal death. CONCLUSIONS: Women who exhibit features of the metabolic syndrome before pregnancy have a higher graded risk of PD and fetal demise. Studies are needed to determine whether modifying a woman's metabolic profile before pregnancy, through modest caloric restriction and increased physical activity, can lower her future risk of PD.

Abruptio Placentae↗
PubMed2005

Influenza and emergency department utilization by elders.

OBJECTIVES: Influenza outbreaks have been associated with worsened emergency department (ED) crowding. We sought to examine the mechanism behind this association. METHODS: A retrospective time series analysis was conducted in Toronto from January 1996 to April 1999. Weekly data on laboratory-confirmed influenza and other respiratory virus cases in the community and visits to all city EDs (n = 20) were obtained. In longitudinal analyses, we determined the association between influenza and changes in ED utilization by younger and older patients with specific diagnoses grouped as major influenza related (MIR) and upper respiratory infection (URI). Time trends in psychiatric visits and their relationship to influenza were used as a control group. RESULTS: A mean of 11,075 ED visits occurred weekly (SD = 698; average age, 39.9 years; 51% women). Four influenza seasons occurred, with weekly incident case counts ranging from 0 to 236; there were a total of 81 weeks with zero new cases between seasons. In multivariable analyses, every ten new cases of influenza active in the community was associated with a 1.5% (95% confidence interval = 1.2 to 1.8) and 1.2% (95% confidence interval = 0.6 to 1.8) absolute increase in the proportion of ED patients who were elders with MIR conditions and URIs, respectively. Influenza was not significantly associated with ED utilization by younger patients; other respiratory viruses were not significantly associated with ED utilization for any patient group. CONCLUSIONS: Influenza season is associated with increased ED utilization by patients aged 65 years and older, most of whom have major respiratory illnesses and may require hospital admission. No association was seen between influenza and utilization by younger patients. Efforts to reduce the impact of influenza seasons on EDs should focus on elders.

Adult↗
PubMed2004

Community influenza outbreaks and emergency department ambulance diversion.

STUDY OBJECTIVE: Influenza has been linked to emergency department (ED) crowding, yet few studies have examined this association. We describe the relationship between ED crowding and influenza outbreaks. METHODS: A retrospective time series analysis was conducted in Toronto from January 1996 to April 1999 (n=170 weeks). We obtained weekly data on laboratory-confirmed influenza and other respiratory virus cases in the community, ED ambulance diversion, and visits to all city EDs (n=20). The main outcome was ambulance diversion, measured as the mean number of hours per week in which EDs were forced to divert all ambulances. RESULTS: A mean of 10,936 ED visits occurred weekly (average age of patients 39.9 years; 51% female patients). EDs diverted ambulances an average of 3.4 hours per week (range 0.3 to 15 hours). Four influenza seasons occurred, lasting between 18 and 30 weeks each, with weekly influenza case counts ranging from 0 to 236. There were fewer than 10 cases per week in 119 of 170 weeks (70%). In time-series models, influenza was independently associated with ED ambulance diversion (P<.0001). For every 100 cases of influenza in the community in a given week, ED ambulance diversion would be expected to increase by 2.5 h/wk at the average ED (95% confidence interval [CI] 1.2 to 3.9 h/wk). During influenza seasons, 24.3% (95% CI 11.3% to 37.2%) of observed weekly ambulance diversion was attributable to influenza. CONCLUSION: Influenza seasons are associated with increased ED ambulance diversion. The impact is substantial but brief because there is little or no influenza activity most of each year.

Ambulances↗
PubMed2004

Emergency department crowding and thrombolysis delays in acute myocardial infarction.

STUDY OBJECTIVE: We estimate the effect of emergency department (ED) crowding on door-to-needle time for patients given intravenous thrombolysis for suspected acute myocardial infarction. METHODS: This was a retrospective observational study of patients thrombolyzed in the ED for suspected acute myocardial infarction in 1998 to 2000 in 25 community and teaching hospital EDs in Ontario. EDs located close together and sharing a common ambulance diversion system were grouped into networks consisting of 2 to 5 hospitals each. At patient registration in an ED, the ambulance diversion status of all EDs in the network was determined. Network crowding was calculated as the percentage of EDs that were diverting ambulances on patient registration, categorized as none (0%), moderate (<60%), and high (> or =60%). Door-to-needle time was defined as time from ED registration to drug administration. Multivariable quantile regression and logistic regression were carried out; covariates included age, sex, ECG characteristics, previous acute myocardial infarction, vital signs, time of presentation, and hospital type. RESULTS: A total of 3,452 thrombolysis patients were included: mean age was 62.9 years, and 73% were male patients. Overall median door-to-needle time was 43 minutes (interquartile ratio 27 to 80). Median door-to-needle time was 40, 45, and 47 minutes in conditions of none, moderate, and high network crowding, respectively ( P <.001). The adjusted odds ratios for door-to-needle time delay (>30 minutes) and major delay (>60 minutes) were 1.32 (95% confidence interval [CI] 0.98 to 1.79) and 1.40 (95% CI 1.12 to 1.75), respectively, for high network crowding compared with none, and 1.21 (95% CI 0.89 to 1.63) and 1.06 (95% CI 0.86 to 1.29), respectively, for moderate crowding compared with none. In multivariate analyses, moderate and high crowding conditions were associated with increased median door-to-needle time (3.0 minutes [95% CI 0.1 to 6.0] and 5.8 minutes [95% CI 2.7 to 9.0], respectively). CONCLUSION: ED crowding is associated with increased door-to-needle times for patients with suspected acute myocardial infarction and may represent a barrier to improving cardiac care in EDs.

Aged↗
PubMed2003

The Canadian C-spine rule versus the NEXUS low-risk criteria in patients with trauma.

BACKGROUND: 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. METHODS: 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. RESULTS: 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<0.001) and more specific (45.1 percent vs. 36.8 percent, P<0.001) for injury, and its use would have resulted in lower radiography rates (55.9 percent vs. 66.6 percent, P<0.001). In secondary analyses that included all patients, the sensitivity and specificity of CCR, assuming that the indeterminate cases were all positive, were 99.4 percent and 40.4 percent, respectively (P<0.001 for both comparisons with the NLC). Assuming that the CCR was negative for all indeterminate cases, these rates were 95.3 percent (P=0.09 for the comparison with the NLC) and 50.7 percent (P=0.001). The CCR would have missed 1 patient and the NLC would have missed 16 patients with important injuries. CONCLUSIONS: For alert patients with trauma who are in stable condition, the CCR is superior to the NLC with respect to sensitivity and specificity for cervical-spine injury, and its use would result in reduced rates of radiography.

Adolescent↗