Improved Assessment of Chest pain Trial (IMPACT): assessing patients with possible acute coronary syndromes.

OBJECTIVE: To examine the safety and efficacy of the Improved Assessment of Chest pain Trial (IMPACT) protocol, a strategy for accelerated assessment of patients presenting to emergency departments (EDs) with chest pain. DESIGN, SETTING AND PARTICIPANTS: IMPACT was an intervention trial at a single tertiary referral hospital (Royal Brisbane and Women's Hospital) during February 2011 - March 2014. 1366 prospectively recruited patients presenting to the ED with symptoms of suspected acute coronary syndrome (ACS) were stratified into groups at low, intermediate or high risk of an ACS. INTERVENTION: High risk patients were treated according to NHFA/CSANZ guidelines. Low and intermediate risk patients underwent troponin testing (sensitive assay) 0 and 2 hours after presentation. Intermediate risk patients underwent objective testing after the second troponin test; low risk patients were discharged without further objective testing. MAIN OUTCOME MEASURES: The primary outcome was an ACS within 30 days of presentation. Secondary outcomes were ED and hospital lengths of stay (LOS). RESULTS: The IMPACT protocol stratified 244 (17.9%) patients to low risk, 789 (57.7%) to intermediate risk, and 333 (24.4%) to high risk categories. The overall 30-day ACS rate was 6.6%, but there were no ACS events in the low risk group, and 14 (1.8%) in the intermediate risk group. The median hospital LOS was 5.1 hours (IQR, 4.2-5.6 h) for low risk and 7.7 hours (IQR, 6.1-21 h) for intermediate risk patients. CONCLUSIONS: The IMPACT protocol safely and efficiently allowed a large proportion of patients presenting to EDs with chest pain to undergo accelerated assessment for risk of an ACS. CLINICAL TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry ACTRN12611000206921.

Clinical utility of the Glasgow Blatchford Score in patients presenting to the emergency department with upper gastrointestinal bleeding: A retrospective cohort study.

OBJECTIVE: Upper gastrointestinal bleeding (UGIB) is a common presentation to EDs. Limited Australian data are available. Study aims were to assess mortality and re-bleeding rates in patients presenting with UGIB as risk-stratified by the Glasgow Blatchford Score (GBS). METHODS: We conducted a retrospective medical chart review of all patients presenting with UGIB to a Brisbane tertiary hospital ED over a 12-month period. This descriptive study summarised the medical characteristics related to UGIB as risk-stratified by the GBS. Non-variceal bleeding was categorised as low-risk (GBS 0-2) or high-risk (GBS 3+). Variceal bleeding was not risk stratified. RESULTS: A total of 211 patients presented with UGIB to the ED. The median age was 57 years, 67% were male. Mortality rates at 30 days were: 0% for GBS 0-2, 3% (95% confidence interval [CI] 0-6) for GBS 3+ and 10% (95% CI 0-21) for variceal groups. The overall 30-day re-bleeding rate was 4.3% (95% CI 2-7). High-risk patients accessed endoscopy according to international best practice of less than 24 h (GBS 3+, 23.7 h; variceal bleeding, 7.3 h). CONCLUSIONS: Mortality and re-bleeding outcomes are similar to other international UGIB cohorts. Patients with a low-risk bleed were appropriately identified and discharged home. Those at higher risk were correctly identified and accessed timely endoscopy. The GBS demonstrated clinical utility in an Australian ED cohort of UGIB bleeding patients.

Clinical and ethical challenges for emergency departments during communicable disease outbreaks: Can lessons from Ebola Virus Disease be applied to the COVID-19 pandemic?

EDs fulfil a frontline function during public health emergencies (PHEs) and will play a pivotal role during the COVID-19 pandemic. This perspective article draws on qualitative data from a longitudinal, ethnographic study of an Australian tertiary ED to illustrate the clinical and ethical challenges faced by EDs during PHEs. Interview data collected during the 2014 Ebola Virus Disease PHE of International Concern suggest that ED clinicians have a strong sense of professional responsibility, but this can be compromised by increased visibility of risk and sub-optimal engagement from hospital managers and public health authorities. The study exposes the tension between a healthcare worker's right to protection and a duty to provide treatment. Given the narrow window of opportunity to prepare for a surge of COVID-19 presentations, there is an immediate need to reflect and learn from previous experiences. To maintain the confidence of ED clinicians, and minimise the risk of moral injury, hospital and public health authorities must urgently develop processes to support ethical healthcare delivery and ensure adequate resourcing of EDs.

Simpson's paradox: A statistician's case study.

Gender equality and workforce diversity has recently been in the forefront of College discussions. Reasons for the difference between various groups may not be as they initially appeared. The results of comparing the outcome between two groups can sometimes be confounded and even reversed by an unrecognised third variable. This concept is known as Simpson's Paradox, and is illustrated here using a renowned case study on potential gender bias for acceptance to Graduate School at the University of California, Berkeley. The investigation showed that males were 1.8 times more likely to be admitted to Graduate School than females in 1973. Initially it appeared that women were discriminated against in the selection process. However, when admissions were re-examined at individual Departments of the School, admission tended to be better for women than men in four of six Departments. This contradiction or paradox tells us that the association between admission and gender was dependent upon on Department. The confounding effect of Department was defined by two characteristics. Firstly, a strong association between Department and admission: some Departments admitted much smaller percentages of applicants than others. Secondly, a strong association between Department and gender: females tended to apply to Departments with lower admission rates. The explanation of differences between groups can be multifactorial. A search for possible confounders will assist in this understanding. This could apply whenever two groups initially appear to differ, but on closer analysis this difference is either unfounded, or even reversed by reference to a third, confounding variable.

Utility of community-acquired pneumonia severity scores in guiding disposition from the emergency department: Intensive care or short-stay unit?

OBJECTIVE: To assess community-acquired pneumonia severity scores from two perspectives: (i) prediction of ICU admission or mortality; and (ii) utility of low scores for prediction of discharge within 48 h, potentially indicating suitability for short-stay unit admission. METHODS: Patients with community-acquired pneumonia were identified from a prospective database of emergency patients admitted with infection. Pneumonia severity index (PSI), CURB-65, CORB, CURXO, SMARTCOP scores and the Infectious Diseases Society of America/American Thoracic Society (IDSA/ATS) minor criteria were calculated. Diagnostic accuracy statistics (sensitivity, specificity, predictive values, likelihood ratios and area under receiver operating characteristic curves [AUROC]) were determined for both end-points. RESULTS: Of 618 patients admitted with community-acquired pneumonia judged eligible for invasive therapies, 75 (12.1%) were admitted to ICU or deceased at 30 days, and 87 (14.1%) were discharged within 48 h. All scores effectively stratified patients into categories of risk. For prediction of severe pneumonia, SMARTCOP, CURXO and IDSA/ATS discriminated well (AUROC 0.84-0.87). SMARTCOP and CURXO showed optimal sensitivity (85% [95% confidence interval (CI) 75-92]), while specificity was highest for CORB and CURB-65 (93% and 94%, respectively). Using lowest risk categories for prediction of discharge within 48 h, only SMARTCOP and CURXO showed specificity >80%. PSI demonstrated highest positive predictive value (31% [95% CI 24-39]) and AUROC (0.74 [95% CI 0.69-0.79]). CONCLUSIONS: Community-acquired pneumonia severity scores had different strengths; SMARTCOP and CURXO were sensitive with potential to rule out severe disease, while the high specificity of CORB and CURB-65 facilitated identification of patients at high risk of requirement for ICU. Low severity scores were not useful to identify patients suitable for admission to short-stay units.

Incidence and outcome of subarachnoid haemorrhage in the general and emergency department populations in Queensland from 2010 to 2014.

OBJECTIVES: To determine: (i) incidence and outcome of subarachnoid haemorrhage (SAH) in the general population; and (ii) proportions of SAH in both the general ED population and in ED patients presenting with headache. METHODS: A population-based study in Queensland from January 2010 to December 2014 was conducted. Data were sourced from the Australian Bureau of Statistics, Queensland Hospital Admitted Patient Data Collection linked to the Queensland death registry and ED Information System. Admitted patients with SAH were identified from ICD-10-AM codes. Inter-hospital transfers and repeat admissions for previously diagnosed SAH were excluded. Pre-hospital deaths from SAH were included. ED patients with headache were identified from ICD-10-AM codes and finding 'headache' in the triage free-text entry. The incidence of SAH, in-hospital mortality, proportions of SAH in the general ED population and ED patients with headache were calculated. RESULTS: There were 1975 incident cases of SAH in admitted patients and 294 pre-hospital deaths from SAH. The incidence of SAH was 9.9 (95% confidence interval [CI] 9.5-10.4) per 100 000 person-years. The incidence standardised to the 'World Standard Population' was 7.0 per 100 000 person-years. The in-hospital mortality was 23.8% (95% CI 22.0-25.8%). SAH was found in 1407 (1.9%, 95% CI 1.8-2.0) of ED patients with headache. Overall, there were 2.4 (95% CI 2.3-2.5) SAH per 10 000 of all ED attendances. CONCLUSIONS: The incidence of SAH was similar to that previously reported for Australia. One in 50 ED patients with headache had SAH. Ten in 50 000 ED attendances had a SAH. These estimates can assist in the risk assessment for SAH.

What is the chance all your trainees will pass the next Fellowship exam: A statistician's view.

Your department has had a good track record over many years for preparing trainees to successfully sit for the ACEM Fellowship exam. On average the pass rate for your trainees is over 80%. Then, to your dismay, suddenly only two of five of your trainees pass the latest Fellowship exam. Does this anomaly necessitate an urgent review of your department's training programme, or is it just a statistical quirk? Let us suppose you can prepare candidates so that they all have at least an 80% chance of passing. The probability that all five candidates would have passed is 32.8% (or 0.85 ) based on the multiplication rule of probability for independent events. The probability that only two of five passed is 5.1% (or 10 × 0.82 × 0.23 ) based on the binomial distribution, which is a probability distribution analogous to the normal distribution. The construction of the binomial distribution depends on two parameters: (i) number of candidates sitting ('n'), and (ii) probability of passing for any individual candidate ('P'). The distribution gives the probability that 'x' number of individuals will pass when 'n' number of individuals sit. Thus despite an 80% pass rate historically, the probability that only two of five candidates will pass is not negligible at 5.1%. It is an anomaly, which we may choose not to act on unless it is recurrent, noting it will be expected to occur naturally about one time out of 20. The real challenge is to maintain or increase that individual probability at 80% or higher.

The chances that an emergency physician will demonstrate three abdominal aortic aneurysms by ultrasound in the emergency department for credentialing: A statistician's view.

The Australasian College for Emergency Medicine requires 15 proctored examinations of the aorta for credentialing in ultrasonography for abdominal aortic aneurysm (AAA). Furthermore, at least three examinations need to be positive for an aneurysm. In the ED where AAA presentations are sporadic, what are the chances that an emergency physician (EP) will have the opportunity to demonstrate three AAAs in the next 12 months? The probability of an event occurring within a given time-frame can be modelled by the Poisson distribution. Central to the Poisson distribution is the infrequency of the event such as encountering an AAA in the ED. An EP working 30 clinical hours/week in our tertiary-referral hospital ED can be expected to encounter 15.6 (3.6 symptomatic + 12 asymptomatic) AAA in the next 12 months. The probability of seeing three or more cases during this time is 99.9%. Assuming a proctor can be found for half the cases, the probability of an EP performing proctored ultrasound examinations in at least three AAAs is 98%. This probability drops to 89% if a proctor can be found for only one-third of cases. For an EP to be almost 100% certain of meeting the credentialing requirements, he/she would need almost 10 proctored ultrasound cases of AAA to be available within his/her shifts during the year. The Poisson distribution has enabled us to model the probability of encountering a given number of AAA in the ED. Analysis such as this may help rationalise the numbers needed for credentialing.