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Background: Initial ED assessment can use early warning scores to identify and prioritise patients who need time-critical treatment. We aimed to determine the accuracy of the National Early Warning Score version 2 (NEWS2) for predicting the need for time-critical treatment., Methods: We undertook a single-centre retrospective observational cohort study. We randomly selected 4000 adults who attended a tertiary hospital ED in England from 1 January 2022 to 31 December 2022 and had NEWS2 routinely recorded on electronic patient records. The first NEWS2 and vital signs were extracted from electronic records. Research nurses selected cases that received a potentially time-critical treatment. Two independent clinical experts then determined whether time-critical treatment was or should have been received using an expert consensus derived list of interventions. We used receiver operating characteristic analysis and calculated sensitivity and specificity at predefined thresholds to evaluate the accuracy of NEWS2 for predicting need for time-critical intervention and, as a secondary outcome, mortality at 7 days., Results: After excluding 10 patients who received their intervention before NEWS2 recording, 164/3990 (4.1%) needed time-critical treatment and 71/3990 (1.8%) died within 7 days. NEWS2 predicted need for time-critical treatment with a c-statistic of 0.807 (95% CI 0.765 to 0.849) and death within 7 days with a c-statistic of 0.865 (95% CI 0.813, 0.917). NEWS2>4 predicted need for time-critical treatment with sensitivity of 51.8% (95% CI 44.2%, 59.3%) and positive predictive value of 25.8% (95% CI 21.3%, 30.7%). 37 of the 45 patients needing emergency surgery, antibiotics for open fractures, insulin infusion or manipulation of limb-threatening injuries had NEWS2≤4. Patients with NEWS2>4 who did not need time-critical treatment frequently scored maximum points on NEWS2 for their respiratory rate, conscious level or receiving supplemental oxygen., Conclusion: NEWS2 has limited accuracy for predicting need for time-critical treatment. We have identified time-critical interventions that frequently have low NEWS2 scores and NEWS2 parameters than may overestimate need for time-critical intervention., Trial Registration Number: Research Registry 10450., Competing Interests: Competing interests: All authors declare funding to their employing institutions from the NIHR RfPB programme (project reference NIHR204935)., (© Author(s) (or their employer(s)) 2025. Re-use permitted under CC BY. Published by BMJ Group.)

Background: Ambulance clinicians use pre-alert calls to inform emergency departments (EDs) about the arrival of critically ill patients. However, there is variation in guidance between local ambulance service policies in terms of what should be pre-alerted and how pre-alerts should happen. We conducted a national online survey to understand the use of ambulance pre-alerts and to inform recommendations for practice and guidance., Methods: Ambulance clinicians in England involved in pre-alert decision-making were recruited via ambulance trusts and social media to complete an anonymous online survey conducted during May-July 2023. Quantitative data was analysed descriptively using SPSS (version 28) and free-text responses are reported to illustrate the quantitative findings., Results: We included 1298 valid responses from 10 English ambulance services. There was variation in practice at all stages of the pre-alert process, including the reported frequency of pre-alert (7.1% several times a shift, 14.9% once/two times per month). Most respondents reported that pre-alerts were delivered directly to the ED, but 32.8% reported pre-alerting via an ambulance control room. A third of respondents always used mnemonics to guide a pre-alert (eg, ATMIST (Age, Time of Incident, Mechanism of injury, Injuries, Signs, Treatments)), but 10.2% reported not using any fixed format.The type of guidance used to identify patients for pre-alert varied between clinicians and ambulance services, with local ambulance service guidance being most commonly used, and 20% stating they never use national guidelines. Respondents reported variable understanding of appropriate conditions for pre-alert, with paramedic students particularly wanted further guidance on trauma in older patients and medical pre-alerts. 29% of respondents reported receiving specific pre-alert training, while 50% reported never receiving feedback., Conclusion: We identified variation in pre-alert processes and practices that may result in uncertainty and challenges for ambulance clinicians providing time-critical care. Guidance and training on the use of pre-alerts may promote more consistent processes and practices., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2025. Re-use permitted under CC BY. Published by BMJ Group.)

Background: Acute aortic syndrome (AAS) requires urgent diagnosis with computed tomographic angiography (CTA). Diagnostic strategies need to weigh the benefits of detecting AAS against the costs of using CTA with a low yield of AAS when the prevalence of AAS is low. We aimed to estimate the cost-effectiveness of diagnostic strategies using clinical probability scoring and D-dimer to select patients with potential symptoms of AAS for CTA., Methods: We developed a decision analytical model to simulate the management of patients attending hospital with possible AAS. We modelled diagnostic strategies that used the Aortic Dissection Detection Risk Score (ADD-RS) and D-dimer to select patients for CTA. We used estimates from our meta-analysis, existing literature and clinical experts to model the consequences of diagnostic strategies on survival, health utility, and health and social care costs. We estimated the incremental cost per quality-adjusted life-years gained by each strategy compared with the next most effective alternative on the efficiency frontier., Results: A strategy based on the Canadian guideline (CTA if ADD-RS>1 or ADD-RS=1 with D-dimer >500 ng/mL) is cost-effective but would result in high rates of CTA if applied to an unselected population (AAS prevalence 0.26%). The strategy is also cost-effective and would result in lower rates of CTA if applied to a more selected population, such as those with a non-zero clinical suspicion of AAS (prevalence 0.61%). For patients currently receiving CTA, using ADD-RS>1 or D-dimer >500 ng/mL to select patients for CTA is cost-effective., Conclusions: A strategy using ADD-RS>1 or ADD-RS=1 with D-dimer >500 ng/mL to select patients for CTA appears cost-effective but primary research is required to evaluate this strategy in practice and determine how suspicion of AAS is identified., Competing Interests: Competing interests: All authors declare funding from NIHR Health Technology Assessment Grant NIHR151853. There are no other competing interests., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY. Published by BMJ.)

Background: D-dimer is the only biomarker currently recommended in guidelines for the diagnosis of acute aortic syndrome (AAS). We undertook a systematic review to determine whether any alternative biomarkers could be useful in AAS diagnosis., Methods: We searched electronic databases (including MEDLINE, EMBASE and the Cochrane Library) from inception to February 2024. Diagnostic studies were eligible if they examined biomarkers other than D-dimer for diagnosing AAS compared with a reference standard test in people presenting to the ED with symptoms of AAS. Case-control studies were identified but excluded due to high risk of bias. Selection of studies, data extraction and risk of bias assessments using the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) tool were undertaken independently by at least two reviewers. We used narrative synthesis to summarise the findings., Results: We identified 2017 citations, included 13 cohort studies (n=76-999), and excluded 38 case-control studies. Methodological quality was variable, with most included studies having unclear or high risk of bias and applicability concerns in at least one item of the QUADAS-2 tool. Only two studies reported biomarkers with sensitivity and specificity comparable to D-dimer (ie, >90% and >50%, respectively). Wang et al reported 99.1% sensitivity and 84.9% specificity for soluble ST2; however, these findings conflicted with estimates of 58% sensitivity and 70.8% specificity reported in another study. Chun and Siu reported 95.6% sensitivity and 56.1% specificity for neutrophil count, but this has not been confirmed elsewhere., Conclusion: There are many potential alternative biomarkers for AAS but few have been evaluated in more than one study, study designs are often weak and reported biomarker accuracy is modest or inconsistent between studies. Alternative biomarkers to D-dimer are not ready for routine clinical use., Prospero Registration Number: CRD42022252121., Competing Interests: Competing interests: SG, AP, ME, MC, GC, RH, MJR, ST and SW all declare funding from NIHR Health Technology Assessment (Grant NIHR151853). There are no other competing interests., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY. Published by BMJ.)

Background: Calls to emergency departments (EDs) from ambulances to alert them to a critical case being transported to that facility that requires a special response ('pre-alerts') have been shown to improve outcomes for patients requiring immediate time-critical treatment (eg, stroke). However, little is known about their usefulness for other patients and the processes involved in ED responses to them. This study aimed to understand how pre-alerts influence patient care in the ED., Methods: We undertook non-participant observation (162 hours, 143 pre-alerts) and semi-structured interviews with staff (n=40) in six UK EDs between August 2022 and April 2023 focusing on how ED staff respond to pre-alert calls and what influences their response. Observation notes and interview transcripts were imported into NVivo and analysed using a thematic approach., Results: Pre-alert calls involved significant time and resources for ED staff but they were valued as they enabled staff to prepare for a patient's arrival (practically and psychologically). High demand and handover delays at ED created additional pre-alerts due to ambulance clinician concerns about the impact of long waits on patients.Despite the risk of pre-alert fatigue from calls for patients considered not to require a special response, ED clinicians appreciated timely pre-alert information, perceiving a higher risk from underalerting than overalerting. Variation in ED response was influenced by individual and organisational factors, particularly the resources available at the time of pre-alert. Unclear ED processes for receiving, documenting and sharing information about pre-alerts increased the risk of information loss., Conclusion: Improving processes for receiving and sharing pre-alert information may help ED clinicians prepare appropriately for incoming patients. Alternative routes for ambulance clinicians to seek advice on borderline pre-alert patients may help to improve the appropriateness of pre-alerts., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY. Published by BMJ.)

Background: The HEART score, the T-MACS model and the GRACE score support early decision-making for acute chest pain, which could be complemented by CT coronary angiography (CTCA). However, their performance has not been directly compared., Methods: In this secondary analysis of a multicentre randomised controlled trial of early CTCA in intermediate-risk patients with suspected acute coronary syndrome, C-statistics and performance metrics (using the predefined cut-offs) of clinical decision aids and CTCA, alone and then in combination, for the index hospital diagnosis of acute coronary syndrome and for 30-day coronary revascularisation were assessed in those who underwent CTCA and had complete data., Results: Among 699 patients, 358 (51%) had an index hospital diagnosis of acute coronary syndrome, for which the C-statistic was higher for CTCA (0.80), followed by the T-MACS model (0.78), the HEART score (0.74) and the GRACE score (0.60). The negative predictive value was higher for the absence of coronary artery disease on CTCA (0.90) or a T-MACS estimate of <0.05 (0.83) than a HEART score of <4 (0.81) and a GRACE score of <109 (0.55). For 30-day coronary revascularisation, CTCA had the greatest C-statistic (0.80) with a negative predictive value of 0.96 and 0.92 in the absence of coronary artery disease and obstructive coronary artery disease, respectively. The combination of the T-MACS estimates and the CTCA findings was most discriminative for the index hospital diagnosis of acute coronary syndrome (C-statistic, 0.88) and predictive of 30-day coronary revascularisation (C-statistic, 0.85). No patients with a T-MACS estimate of <0.05 and normal coronary arteries had acute coronary syndrome during index hospitalisation or underwent coronary revascularisation within 30 days., Conclusions: In intermediate-risk patients with suspected acute coronary syndrome, the T-MACS model combined with CTCA improved discrimination of the index hospital diagnosis of acute coronary syndrome and prediction of 30-day coronary revascularisation., Trial Registration Number: NCT02284191., Competing Interests: Competing interests: KO reports research grants from the British Heart Foundation, the Jon Moulton Charity Trust and University of Edinburgh. RFS reports research grants from AstraZeneca and Cytosorbents; consulting fees and/or honoraria from Alfasigma, AstraZeneca, Chiesi, Cytosorbents, Daiichi-Sankyo, Idorsia, Novartis, Novo Nordisk, Pfizer, PhaseBio and Tabuk. NC reports research grants from Beckman Coulter, Boston Scientific, HeartFlow and Haemonetics; consulting fees and/or honoraria from Abbott, Boston Scientific and Edwards Lifesciences; travel sponsorship from Abbott, Biosensors and Edwards Lifesciences. AK reports honoraria from the TomTec Imaging Systems. CR reports honoraria from GE HealthCare., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Objective: To assess accuracy of telephone triage in identifying need for emergency care among those with suspected COVID-19 infection and identify factors which affect triage accuracy., Design: Observational cohort study., Setting: Community telephone triage provided in the UK by Yorkshire Ambulance Service NHS Trust (YAS)., Participants: 40 261 adults who contacted National Health Service (NHS) 111 telephone triage services provided by YAS between 18 March 2020 and 29 June 2020 with symptoms indicating COVID-19 infection were linked to Office for National Statistics death registrations and healthcare data collected by NHS Digital., Outcome: Accuracy of triage disposition was assessed in terms of death or need for organ support up to 30 days from first contact., Results: Callers had a 3% (1200/40 261) risk of serious adverse outcomes (death or organ support). Telephone triage recommended self-care or non-urgent assessment for 60% (24 335/40 261), with a 1.3% (310/24 335) risk of adverse outcomes. Telephone triage had 74.2% sensitivity (95% CI: 71.6 to 76.6%) and 61.5% specificity (95% CI: 61% to 62%) for the primary outcome. Multivariable analysis suggested respiratory comorbidities may be overappreciated, and diabetes underappreciated as predictors of deterioration. Repeat contact with triage service appears to be an important under-recognised predictor of deterioration with 2 contacts (OR 1.77, 95% CI: 1.14 to 2.75) and 3 or more contacts (OR 4.02, 95% CI: 1.68 to 9.65) associated with false negative triage., Conclusion: Patients advised to self-care or receive non-urgent clinical assessment had a small but non-negligible risk of serious clinical deterioration. Repeat contact with telephone services needs recognition as an important predictor of subsequent adverse outcomes., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY. Published by BMJ.)

Background: The diagnosis of acute aortic syndrome (AAS) is commonly delayed or missed in the ED. We describe characteristics of ED attendances with symptoms potentially associated with AAS, diagnostic performance of clinical decision tools (CDTs) and physicians and yield of CT aorta angiogram (CTA)., Methods: This was a multicentre observational cohort study of adults attending 27 UK EDs between 26 September 2022 and 30 November 2022, with potential AAS symptoms: chest, back or abdominal pain, syncope or symptoms related to malperfusion. Patients were preferably identified prospectively, but retrospective recruitment was also permitted. Anonymised, routinely collected patient data including components of CDTs, was abstracted. Clinicians treating prospectively identified patients were asked to record their perceived likelihood of AAS, prior to any confirmatory testing. Reference standard was radiological or operative confirmation of AAS. 30-day electronic patient record follow-up evaluated whether a subsequent diagnosis of AAS had been made and mortality., Results: 5548 patients presented, with a median age of 55 years (IQR 37-72; n=5539). 14 (0.3%; n=5353) had confirmed AAS. 10/1046 (1.0%) patients in whom the ED clinician thought AAS was possible had AAS. 5/147 (3.4%) patients in whom AAS was considered the most likely diagnosis had AAS. 2/3319 (0.06%) patients in whom AAS was considered not possible did have AAS. 540 (10%; n=5446) patients underwent CT, of which 407 were CTA (7%). 30-day follow-up did not reveal any missed AAS diagnoses. AUROC (area under the receiver operating characteristic) curve for ED clinician AAS likelihood rating was 0.958 (95% CI 0.933 to 0.983, n=4006) and for individual CDTs were: Aortic Dissection Detection Risk Score (ADD-RS) 0.674 (95% CI 0.508 to 0.839, n=4989), AORTAs 0.689 (95% CI 0.527 to 0.852, n=5132), Canadian 0.818 (95% CI 0.686 to 0.951, n=5180) and Sheffield 0.628 (95% CI 0.467 to 0.788, n=5092)., Conclusion: Only 0.3% of patients presenting with potential AAS symptoms had AAS but 7% underwent CTA. CDTs incorporating clinician gestalt appear to be most promising, but further prospective work is needed, including evaluation of the role of D-dimer., Trial Registration Number: NCT05582967; NCT05582967., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Competing Interests: Competing interests: None declared.

Background: Ambulance services need to identify and prioritise patients with sepsis for early hospital assessment. We aimed to determine the accuracy of early warning scores alongside paramedic diagnostic impression to identify sepsis that required urgent treatment., Methods: We undertook a retrospective diagnostic cohort study involving adult emergency medical cases transported to Sheffield Teaching Hospitals ED by Yorkshire Ambulance Service in 2019. We used routine ambulance service data to calculate 21 early warning scores and categorise paramedic diagnostic impressions as sepsis, infection, non-specific presentation or other presentation. We linked cases to hospital records and identified those meeting the sepsis-3 definition who received urgent hospital treatment for sepsis (reference standard). Analysis determined the accuracy of strategies that combined early warning scores at varying thresholds for positivity with paramedic diagnostic impression., Results: We linked 12 870/24 955 (51.6%) cases and identified 348/12 870 (2.7%) with a positive reference standard. None of the strategies provided sensitivity greater than 0.80 with positive predictive value greater than 0.15. The area under the receiver operating characteristic curve for the National Early Warning Score, version 2 (NEWS2) applied to patients with a diagnostic impression of sepsis or infection was 0.756 (95% CI 0.729, 0.783). No other early warning score provided clearly superior accuracy to NEWS2. Paramedic impression of sepsis or infection had sensitivity of 0.572 (0.519, 0.623) and positive predictive value of 0.156 (0.137, 0.176). NEWS2 thresholds of >4, >6 and >8 applied to patients with a diagnostic impression of sepsis or infection, respectively, provided sensitivities and positive predictive values of 0.522 (0.469, 0.574) and 0.216 (0.189, 0.245), 0.447 (0.395, 0.499) and 0.274 (0.239, 0.313), and 0.314 (0.268, 0.365) and 0.333 (0.284, 0.386)., Conclusion: No strategy is ideal but using NEWS2 alongside paramedic diagnostic impression of infection or sepsis could identify one-third to half of sepsis cases without prioritising unmanageable numbers. No other score provided clearly superior accuracy to NEWS2., Trial Registration Number: researchregistry5268, https://www.researchregistry.com/browse-the-registry%23home/registrationdetails/5de7bbd97ca5b50015041c33/., Competing Interests: Competing interests: All authors declare grant funding to their employing institutions from the National Institute for Health Research., (© Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY. Published by BMJ.)

Clinical risk prediction models can support decision making in emergency medicine, but directing intervention towards high-risk patients may involve a flawed assumption. This concepts paper examines prognostic clinical risk prediction and specifically describes the potential impact of treatment effects in model development studies. Treatment effects may lead to models failing to achieve the aim of identifying the patients most likely to benefit from intervention, and may instead identify patients who are unlikely to benefit from intervention. The paper provides practical advice to help clinicians who wish to use clinical prediction scores to assist clinical judgement rather than dictate clinical decision making., Competing Interests: Competing interests: SG was the Chief Investigator for the PRIEST Study., (© Author(s) (or their employer(s)) 2023. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Tools proposed to triage ED acuity in suspected COVID-19 were derived and validated in higher income settings during early waves of the pandemic. We estimated the accuracy of seven risk-stratification tools recommended to predict severe illness in the Western Cape, South Africa., Methods: An observational cohort study using routinely collected data from EDs across the Western Cape, from 27 August 2020 to 11 March 2022, was conducted to assess the performance of the PRIEST (Pandemic Respiratory Infection Emergency System Triage) tool, NEWS2 (National Early Warning Score, version 2), TEWS (Triage Early Warning Score), the WHO algorithm, CRB-65, Quick COVID-19 Severity Index and PMEWS (Pandemic Medical Early Warning Score) in suspected COVID-19. The primary outcome was intubation or non-invasive ventilation, death or intensive care unit admission at 30 days., Results: Of the 446 084 patients, 15 397 (3.45%, 95% CI 34% to 35.1%) experienced the primary outcome. Clinical decision-making for inpatient admission achieved a sensitivity of 0.77 (95% CI 0.76 to 0.78), specificity of 0.88 (95% CI 0.87 to 0.88) and the negative predictive value (NPV) of 0.99 (95% CI 0.99 to 0.99). NEWS2, PMEWS and PRIEST scores achieved good estimated discrimination (C-statistic 0.79 to 0.82) and identified patients at risk of adverse outcomes at recommended cut-offs with moderate sensitivity (>0.8) and specificity ranging from 0.41 to 0.64. Use of the tools at recommended thresholds would have more than doubled admissions, with only a 0.01% reduction in false negative triage., Conclusion: No risk score outperformed existing clinical decision-making in determining the need for inpatient admission based on prediction of the primary outcome in this setting. Use of the PRIEST score at a threshold of one point higher than the previously recommended best approximated existing clinical accuracy., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY. Published by BMJ.)

Objectives: To estimate the cost-effectiveness of early CT coronary angiography (CTCA) for intermediate risk patients with suspected acute coronary syndrome (ACS), compared with standard care METHODS: We performed within-trial economic analysis using data from the RAPID-CTCA randomised trial, and long-term modelling of cost-effectiveness using secondary data sources to estimate the cost-effectiveness of early CTCA compared with standard care for patients with suspected ACS attending acute hospitals in the UK. Cost-effectiveness was estimated as the incremental cost per quality-adjusted life year (QALY) gained, and the probability of each strategy being cost-effective at varying willingness-to-pay per QALY gained., Results: The within-trial analysis showed that there were no demonstrable differences in costs or QALYs between early CTCA and standard care, with point estimates suggesting higher costs (£7414 vs £6845: mean difference £569, 95% CI -£208 to £1335; p=0.1521) and lower QALYs (0.749 vs 0.758, mean difference -0.009, 95% CI -0.026 to 0.010; p=0.377) in the CTCA arm. The long-term economic analysis suggested that, on average, CTCA was slightly less effective than standard care alone with 0.025 quality-adjusted life years lost per patient treated and was more expensive with additional costs of £481 per patient treated. At a threshold of £20 000 per QALY, CTCA has 24% probability of being cost-effective., Conclusions: There are no demonstrable differences in within-trial costs and QALYs, and long-term cost-effectiveness modelling suggested higher long-term costs with CTCA and uncertain effect on long-term QALYs, making routine use of CTCA for suspected ACS unlikely to be a cost-effective use of NHS resources., Competing Interests: Competing interests: AG is a member of the National Institute for Health and Care Research (NIHR) Health Technology Assessment (HTA) Prioritisation Committee. SG is the chairperson of the NIHR CTU Standing Advisory Committee. He was the deputy director of the NIHR HTA programme; chairperson of the NIHR HTA Commissioning Committee and a member of the HTA Post-Funding Committee, HTA Funding Committee Policy Group and HTA Programme Oversight Committee. DEN is a Deputy Editor for BMJ Heart. He also reports unrestricted educational grants from Siemens Healthineers (Erlangen, Germany)., (© Author(s) (or their employer(s)) 2023. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Guidelines for adults presenting to the emergency department (ED) with suspected sepsis recommend protocols and bundles that promote rapid and potentially intensive treatment, but give little consideration of how patient characteristics, such as age, functional status and comorbidities, might influence management. This study aimed to describe the characteristics, management and outcomes of adults attending the ED with suspected sepsis, and specifically describe the prevalence of comorbidities, functional impairment and escalations of care., Methods: We undertook a single-centre retrospective observational study involving medical record review of a random sample of adults admitted to an ED between February 2018 and January 2019 with suspected sepsis. Descriptive statistics were used with 95% confidence intervals (CIs) for key proportions., Results: We included 509 patients (median age 74 years), of whom 49.3% met the Sepsis-3 criteria. Less than half of the patients were living at home independently (42.5%) or could walk independently (41.5%), 19.3% were care home residents and 89.2% of patients had one or more comorbidity. 22% had a pre-existing do not attempt resuscitation order. 6.5% were referred to intensive care, and 34.3% of the 13.2% who died in-hospital had an escalation plan explicitly documented., Conclusion: Adults with suspected sepsis have substantial functional limitations, comorbidities and treatment directives that should be considered in guidelines, especially recommendations for escalation of care., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2022. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Tools proposed to triage patient acuity in COVID-19 infection have only been validated in hospital populations. We estimated the accuracy of five risk-stratification tools recommended to predict severe illness and compared accuracy to existing clinical decision making in a prehospital setting., Methods: An observational cohort study using linked ambulance service data for patients attended by Emergency Medical Service (EMS) crews in the Yorkshire and Humber region of England between 26 March 2020 and 25 June 2020 was conducted to assess performance of the Pandemic Respiratory Infection Emergency System Triage (PRIEST) tool, National Early Warning Score (NEWS2), WHO algorithm, CRB-65 and Pandemic Medical Early Warning Score (PMEWS) in patients with suspected COVID-19 infection. The primary outcome was death or need for organ support., Results: Of the 7549 patients in our cohort, 17.6% (95% CI 16.8% to 18.5%) experienced the primary outcome. The NEWS2 (National Early Warning Score, version 2), PMEWS, PRIEST tool and WHO algorithm identified patients at risk of adverse outcomes with a high sensitivity (>0.95) and specificity ranging from 0.3 (NEWS2) to 0.41 (PRIEST tool). The high sensitivity of NEWS2 and PMEWS was achieved by using lower thresholds than previously recommended. On index assessment, 65% of patients were transported to hospital and EMS decision to transfer patients achieved a sensitivity of 0.84 (95% CI 0.83 to 0.85) and specificity of 0.39 (95% CI 0.39 to 0.40)., Conclusion: Use of NEWS2, PMEWS, PRIEST tool and WHO algorithm could improve sensitivity of EMS triage of patients with suspected COVID-19 infection. Use of the PRIEST tool would improve sensitivity of triage without increasing the number of patients conveyed to hospital., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2022. Re-use permitted under CC BY. Published by BMJ.)

Background: Sepsis is a major cause of morbidity and mortality and many tools exist to facilitate early recognition. This review compares two tools: the quick Sequential Organ Failure Assessment (qSOFA) and Early Warning Scores (National/Modified Early Warning Scores (NEWS/MEWS)) for predicting intensive care unit (ICU) admission and mortality when applied in the emergency department., Methods: A literature search was conducted using Medline, CINAHL, Embase and Cochrane Library, handsearching of references and a grey literature search with no language or date restrictions. Two authors selected studies and quality assessment completed using QUADAS-2. Area under the receiver operating characteristic curve (AUROC), sensitivities and specificities were compared., Results: 13 studies were included, totalling 403 865 patients. All reported mortality and six reported ICU admission.The ranges for AUROC estimates varied from little better than chance to good prediction of mortality (NEWS: 0.59-0.88; qSOFA: 0.57-0.79; MEWS 0.56-0.75), however, individual papers generally reported higher AUROC values for NEWS than qSOFA. NEWS values demonstrated a tendency towards better sensitivity for ICU admission (NEWS ≥5, 46%-91%; qSOFA ≥2, 12%-53%) and mortality (NEWS ≥5, 51%-97%; qSOFA ≥2, 14%-71%) but lower specificity (ICU: NEWS ≥5, 25%-91%; qSOFA ≥2, 67%-99%; mortality: NEWS ≥5, 22%-91%; qSOFA ≥2, 58%-99%)., Conclusion: The wide range of AUROC estimates and high heterogeneity limit our conclusions. Allowing for this, the NEWS AUROC was consistently higher than qSOFA within individual papers. Both scores allow threshold setting, determined by the preferred compromise between sensitivity and specificity. At established thresholds NEWS tended to higher sensitivity while qSOFA tended to a higher specificity., Prospero Registration Number: CRD42019131414., Competing Interests: Competing interests: SG is chief investigator for the PHEWS study (Pre-Hospital Early Warning Scores for Sepsis), funded by the National Institute for Health Research Health Technology Assessment Programme (Reference 17/136/10). This paper was not undertaken as part of the PHEWS study., (© Author(s) (or their employer(s)) 2022. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: The WHO and National Institute for Health and Care Excellence recommend various triage tools to assist decision-making for patients with suspected COVID-19. We aimed to compare the accuracy of triage tools for predicting severe illness in adults presenting to the ED with suspected COVID-19., Methods: We undertook a mixed prospective and retrospective observational cohort study in 70 EDs across the UK. We collected data from people attending with suspected COVID-19 and used presenting data to determine the results of assessment with the WHO algorithm, National Early Warning Score version 2 (NEWS2), CURB-65, CRB-65, Pandemic Modified Early Warning Score (PMEWS) and the swine flu adult hospital pathway (SFAHP). We used 30-day outcome data (death or receipt of respiratory, cardiovascular or renal support) to determine prognostic accuracy for adverse outcome., Results: We analysed data from 20 891 adults, of whom 4611 (22.1%) died or received organ support (primary outcome), with 2058 (9.9%) receiving organ support and 2553 (12.2%) dying without organ support (secondary outcomes). C-statistics for the primary outcome were: CURB-65 0.75; CRB-65 0.70; PMEWS 0.77; NEWS2 (score) 0.77; NEWS2 (rule) 0.69; SFAHP (6-point rule) 0.70; SFAHP (7-point rule) 0.68; WHO algorithm 0.61. All triage tools showed worse prediction for receipt of organ support and better prediction for death without organ support. At the recommended threshold, PMEWS and the WHO criteria showed good sensitivity (0.97 and 0.95, respectively) at the expense of specificity (0.30 and 0.27, respectively). The NEWS2 score showed similar sensitivity (0.96) and specificity (0.28) when a lower threshold than recommended was used., Conclusion: CURB-65, PMEWS and the NEWS2 score provide good but not excellent prediction for adverse outcome in suspected COVID-19, and predicted death without organ support better than receipt of organ support. PMEWS, the WHO criteria and NEWS2 (using a lower threshold than usually recommended) provide good sensitivity at the expense of specificity., Trial Registration Number: ISRCTN56149622., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2021. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Alcohol intoxication management services (AIMS) provide an alternative care pathway for alcohol-intoxicated adults otherwise requiring emergency department (ED) services and at times of high incidence. We estimate the effectiveness and cost-effectiveness of AIMS on ED attendance rates with ED and ambulance service performance indicators as secondary outcomes., Methods: A controlled longitudinal retrospective observational study in English and Welsh towns, six with AIMS and six without. Control and intervention cities were matched by sociodemographic characteristics. The primary outcome was ED attendance rate per night, secondary analyses explored hospital admission rates and ambulance response times. Interrupted time series analyses compared control and matched intervention sites pre-AIMS and post-AIMS. Cost-effectiveness analyses compared the component costs of AIMS to usual care before with results presented from the National Health Service and social care prospective. The number of diversions away from ED required for a service to be cost neutral was determined., Results: Analyses found considerable variation across sites, only one service was associated with a significant reduction in ED attendances (-4.89, p<0.01). The services offered by AIMS varied. On average AIMS had 7.57 (mean minimum=1.33, SD=1.37 to mean maximum=24.66, SD=12.58) in attendance per session, below the 11.02 diversions away from ED at which services would be expected to be cost neutral., Conclusions: AIMSs have variable effects on the emergency care system, reflecting variable structures and processes, but may be associated with modest reductions in the burden on ED and ambulance services. The more expensive model, supported by the ED, was the only configuration likely to divert patients away from ED. AIMS should be regarded as fledgling services that require further work to realise benefit., Trial Registration Number: ISRCTN63096364., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2021. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Measurement of post-exertion oxygen saturation has been proposed to assess illness severity in suspected COVID-19 infection. We aimed to determine the accuracy of post-exertional oxygen saturation for predicting adverse outcome in suspected COVID-19., Methods: We undertook a substudy of an observational cohort study across 70 emergency departments during the first wave of the COVID-19 pandemic in the UK. We collected data prospectively, using a standardised assessment form, and retrospectively, using hospital records, from patients with suspected COVID-19, and reviewed hospital records at 30 days for adverse outcome (death or receiving organ support). Patients with post-exertion oxygen saturation recorded were selected for this analysis. We constructed receiver-operating characteristic curves, calculated diagnostic parameters, and developed a multivariable model for predicting adverse outcome., Results: We analysed data from 817 patients with post-exertion oxygen saturation recorded after excluding 54 in whom measurement appeared unfeasible. The c-statistic for post-exertion change in oxygen saturation was 0.589 (95% CI 0.465 to 0.713), and the positive and negative likelihood ratios of a 3% or more desaturation were, respectively, 1.78 (1.25 to 2.53) and 0.67 (0.46 to 0.98). Multivariable analysis showed that post-exertion oxygen saturation was not a significant predictor of adverse outcome when baseline clinical assessment was taken into account (p=0.368). Secondary analysis excluding patients in whom post-exertion measurement appeared inappropriate resulted in a c-statistic of 0.699 (0.581 to 0.817), likelihood ratios of 1.98 (1.26 to 3.10) and 0.61 (0.35 to 1.07), and some evidence of additional prognostic value on multivariable analysis (p=0.019)., Conclusions: Post-exertion oxygen saturation provides modest prognostic information in the assessment of selected patients attending the emergency department with suspected COVID-19., Trial Registration Number: ISRCTN Registry (ISRCTN56149622) http://www.isrctn.com/ISRCTN28342533., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2021. Re-use permitted under CC BY. Published by BMJ.)

Background: We aimed to estimate the diagnostic accuracy of the VitalScan magnetocardiograph (MCG) for suspected acute coronary syndrome (ACS)., Methods: We undertook a prospective cohort study evaluating the diagnostic accuracy of the MCG in adults with suspected ACS. The reference standard of ACS was determined by an independent adjudication committee based on 30-day investigations and events. The cohort was split into a training sample, to derive the MCG algorithm and an algorithm combining MCG with a modified Manchester Acute Coronary Syndrome (MACS) clinical probability score, and a validation sample, to estimate diagnostic accuracy., Results: We recruited 756 participants and analysed data from 680 (293 training, 387 validation), of whom 96 (14%) had ACS. In the training sample, the respective area under the receiver operating characteristic (AUROC) curves were the following: MCG 0.66 (95% CI 0.58 to 0.74), MACS 0.64 (95% CI 0.54 to 0.73) and MCG+MACS 0.70 (95% CI 0.63 to 0.77). MCG specificity was 0.16 (95% CI 0.12 to 0.21) at the threshold achieving acceptable sensitivity for rule-out (>0.98). In the validation sample (n=387), the respective AUROCs were the following: MCG 0.56 (95% CI 0.48 to 0.64), MACS 0.69 (95% CI 0.61 to 0.77) and MCG+MACS 0.64 (95% CI 0.56 to 0.72). MCG sensitivity was 0.89 (95% CI 0.77 to 0.95) and specificity 0.15 (95% CI 0.12 to 0.20) at the rule-out threshold. MCG+MACS sensitivity was 0.85 (95% CI 0.73 to 0.92) and specificity 0.30 (95% CI 0.25 to 0.35)., Conclusion: The VitalScan MCG is currently unable to accurately rule out ACS and is not yet ready for use in clinical practice. Further developmental research is required., Competing Interests: Competing interests: The University of Sheffield received funding from Creavo Medical Technologies for the time committed to the study by its employees (SG, SJW)., (© Author(s) (or their employer(s)) 2021. No commercial re-use. See rights and permissions. Published by BMJ.)

Objective: Recent studies suggest that combinations of clinical probability assessment (the YEARS algorithm or Geneva score) and D-dimer can safely rule out suspected pulmonary embolism (PE) in pregnant women. We performed a secondary analysis of the DiPEP (Diagnosis of Pulmonary Embolism in Pregnancy) study data to determine the diagnostic accuracy of these strategies., Methods: The DiPEP study prospectively recruited and collected data and blood samples from pregnant/postpartum women with suspected PE across 11 hospitals and retrospectively collected data from pregnant/postpartum women with diagnosed PE across all UK hospitals (15 February 2015 to 31 August 2016). We selected prospectively recruited pregnant women who had definitive diagnostic imaging for this analysis. We used clinical data and D-dimer results to determine whether the rule out strategies would recommend further investigation. Two independent adjudicators used data from imaging reports, treatments and adverse events up to 30 days to determine the reference standard., Results: PEs were diagnosed in 12/219 (5.5%) women. The YEARS/D-dimer strategy would have ruled out PE in 96/219 (43.8%) but this would have included 5 of the 12 with PEs. Sensitivity for PE was 58.3% (95% CI 28.6% to 83.5%) and specificity 44.0% (37.1% to 51.0%). The Geneva/D-dimer strategy would have ruled out PE in 46/219 (21.0%) but this would have included three of the 12 with PE. Sensitivity was 75.0% (95% CI 42.8% to 93.3%) and specificity 20.8% (95% CI 15.6% to 27.1%). Administration of anticoagulants prior to blood sampling may have reduced D-dimer sensitivity for small PE., Conclusion: Strategies using clinical probability and D-dimer have limited diagnostic accuracy and do not accurately rule out all PE in pregnancy. It is uncertain whether PE missed by these strategies lead to clinically important consequences., Competing Interests: Competing interests: The study was funded by the NIHR Health Technology Assessment Programme. SG is deputy director of the HTA Programme and chairs the HTA Commissioning Committee., (© Author(s) (or their employer(s)) 2020. Re-use permitted under CC BY. Published by BMJ.)

Objectives: Recent guidance recommended use of high-sensitivity troponin for rapid rule out of myocardial infarction (MI) in the English health service. We aimed to determine the extent of implementation of this guidance across English hospitals., Methods: This study conducted a cross-sectional questionnaire survey of 131 English acute hospitals with over 10 000 admissions per year., Results: We received 125/131 responses (95%), with 110/125 (88%) reporting use of a high-sensitivity troponin assay and responses showing progressive implementation over the last 10 years. High-sensitivity troponin was reported to be used for rapid rule out of MI in 92/110 Trusts (84%). Review of guidelines received from 95/110 Trusts identified that 71/95 (75%) provided guidance for rapid MI rule out with high-sensitivity troponin: 57 recommended testing at 0 and 3 hours, 4 recommended testing at 0 and 2 hours, and 9 recommended testing at 0 and 1 hour, and timing was unclear at one Trust., Conclusions: English acute hospital Trusts report widespread implementation of high-sensitivity troponin for rapid rule out of MI, with most recommending testing at 0 and 3 hours., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2020. No commercial re-use. See rights and permissions. Published by BMJ.)

Introduction: Inadequate pain management in EDs is a worldwide problem, yet there has been little progress in understanding how pain management can be improved. There is only weak evidence and limited rationale to support interventions to improve pain management. We used naturalistic, qualitative methods to understand the factors that influence how pain is managed within the adult ED., Methods: We used a multiple case study design incorporating 143-hour non-participant observation, documentary analysis and semistructured interviews with 37 staff and 19 patients at three EDs in the North of England between 2014 and 2016. We analysed data using thematic analysis., Results: Our analysis demonstrated that pain management was not well aligned with the core priorities of the ED and was overlooked when other works took priority. We identified that (1) pain management was not perceived to be a key organisational priority for which staff were held accountable and staff had limited awareness of their performance, (2) pain management was not a core component of ED education and training, (3) ED processes and structures were not aligned with pain management and pain reassessment was overlooked unless staff escalated pain management outside of normal processes and (4) staff held embedded beliefs that conceptualised pain management as distinct from core priorities and limited their capacity to improve. However, EDs were able to improve pain management by aligning processes of pain management with other core works, particularly patient flow (eg, nurse-initiated analgesia at triage)., Implications: EDs may be able to improve pain management by ensuring pain management processes align with key ED priorities. Undertaking multifaceted changes to structures and processes may enable staff to improve pain management and develop a culture in which pain management can be prioritised more easily. Future interventions need to be compatible with the wider work of the ED and enable patient flow in order to be adopted and maintained., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2020. No commercial re-use. See rights and permissions. Published by BMJ.)

Venous thromboembolic disease is a major global cause of morbidity and mortality. An estimated 10 million episodes are diagnosed yearly; over half of these episodes are provoked by hospital admission/procedures and result in significant loss of disability adjusted life years. Temporary lower limb immobilisation after injury is a significant contributor to the overall burden of venous thromboembolism (VTE). Existing evidence suggests that pharmacological prophylaxis could reduce overall VTE event rates in these patients, but the proportional reduction of symptomatic events remains unclear. Recent studies have used different pharmacological agents, dosing regimens and outcome measures. Consequently, there is wide variation in thromboprophylaxis strategies, and international guidelines continue to offer conflicting advice for clinicians. In this review, we provide a summary of recent evidence assessing both the clinical and cost effectiveness of thromboprophylaxis in patients with temporary immobilisation after injury. We also examine the evidence supporting stratified thromboprophylaxis and the validity of widely used risk assessment methods., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2020. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Patients presenting with chest pain represent a significant proportion of attendances to the ED. The History, ECG, Age, Risk Factors and Troponin (HEART) Score is validated for the risk stratification of suspected ischaemic chest pain within the ED. The goal of this research was to establish the interoperator reliability of the HEART Score as performed in the ED by different grades of doctor and nurse., Methodology: Patients with suspected ischaemic chest pain presenting to the ED of an inner city, London Hospital, were recruited prospectively between January and May 2016. Patients that had been enrolled in the study were interviewed by clinicians from four different categories: senior doctor, junior doctor, senior nurse and junior nurse. Clinicians, blinded to other raters' results, calculated the HEART Scores for each patient with the assistance of a pocket-sized HEART Score card. The intraclass correlation coefficient (ICC) was calculated as the primary measure of reliability. 120 patients were required to achieve a desired power of 80%., Results: 88 complete comparisons were obtained. There were no significant differences between the distributions of HEART Scores for each clinician group (p=0.95). The ICC for the overall HEART Score was 0.91 (95% CI 0.87 to 0.93). The ICC for troponin and age were '1', for 'history' 0.41 (95% CI 0.30 to 0.52), 'ECG' 0.64 (95% CI 0.54 to0.73) and 'risk factors' 0.84 (95% CI 0.79 to 0.89)., Conclusion: This study demonstrates very strong overall interoperator reliability between the four groups of clinicians studied. This suggests that the HEART Score is reproducible when used by different professional groups and grade of clinician., Competing Interests: Competing interests: Dr Niven reports grants from Royal College of Emergency Medicine, during the conduct of the study; and I have collaborated with Dr Barbra Backus, one of the original developers of the HEART Score, in creating a teaching video for the HEART Score., (© Author(s) (or their employer(s)) 2018. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Objectives: Patient flow and crowding are two major issues in ED service improvement. A substantial amount of literature exists on the interventions to improve patient flow and crowding, making it difficult for policymakers, managers and clinicians to be familiar with all the available literature and identify which interventions are supported by the evidence. This umbrella review provides a comprehensive analysis of the evidence from existing quantitative systematic reviews on the interventions that improve patient flow in EDs., Methods: An umbrella review of systematic reviews published between 2000 and 2017 was undertaken. Included studies were systematic reviews and meta-analyses of quantitative primary studies assessing an intervention that aimed to improve ED throughput., Results: The search strategy yielded 623 articles of which 13 were included in the umbrella review. The publication dates of the systematic reviews ranged from 2006 to 2016. The 13 systematic reviews evaluated 26 interventions: full capacity protocols, computerised provider order entry, scribes, streaming, fast track and triage. Interventions with similar characteristics were grouped together to produce the following categories: diagnostic services, assessment/short stay units, nurse-directed interventions, physician-directed interventions, administrative/organisational and miscellaneous. The statistical evidence from 14 primary randomised controlled trials (RCTs) was evaluated to determine if correlation or clustering of observations was considered. Only the fast track intervention had moderate evidence to support its use but the RCTs that assessed the intervention did not use statistical tests that considered correlation., Conclusions: Overall, the evidence supporting the interventions to improve patient flow is weak. Only the fast track intervention had moderate evidence to support its use but correlation/clustering was not taken into consideration in the RCTs examining the intervention. Failure to consider the correlation of the data in the primary studies could result in erroneous conclusions of effectiveness., Competing Interests: Competing interests: None declared., (© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)

Background: Adaptive design clinical trials use preplanned interim analyses to determine whether studies should be stopped or modified before recruitment is complete. Emergency medicine trials are well suited to these designs as many have a short time to primary outcome relative to the length of recruitment. We hypothesised that the majority of published emergency medicine trials have the potential to use a simple adaptive trial design., Methods: We reviewed clinical trials published in three emergency medicine journals between January 2003 and December 2013. We determined the proportion that used an adaptive design as well as the proportion that could have used a simple adaptive design based on the time to primary outcome and length of recruitment., Results: Only 19 of 188 trials included in the review were considered to have used an adaptive trial design. A total of 154/165 trials that were fixed in design had the potential to use an adaptive design., Conclusions: Currently, there seems to be limited uptake in the use of adaptive trial designs in emergency medicine despite their potential benefits to save time and resources. Failing to take advantage of adaptive designs could be costly to patients and research. It is recommended that where practical and logistical considerations allow, adaptive designs should be used for all emergency medicine clinical trials., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.)

Patients participate in emergency care research and are the intended beneficiaries of research findings. The public provide substantial funding for research through taxation and charitable donations. If we do research to benefit patients and the public are funding the research, then patients and the public should be involved in the planning, prioritisation, design, conduct and oversight of research, yet patient and public involvement (or more simply, public involvement, since patients are also members of the public) has only recently developed in emergency care research. In this article, we describe what public involvement is and how it can help emergency care research. We use the development of a pioneering public involvement group in emergency care, the Sheffield Emergency Care Forum, to provide insights into the potential and challenges of public involvement in emergency care research., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/)

Background: The appropriate management of patients with ST-segment elevation myocardial infarction (STEMI) depends on accurate interpretation of the 12-lead ECG by paramedics. Computer interpretation messages on ECGs are often provided, but the effect they exert on paramedics' decision-making is not known. The objective of this study was to assess the feasibility of using an online assessment tool, and collect pilot data, for a definitive trial to determine the effect of computer interpretation messages on paramedics' diagnosis of STEMI., Methods: The Recognition of STEMI by Paramedics and the Effect of Computer inTerpretation (RESPECT) feasibility study was a randomised crossover trial using a bespoke, web-based assessment tool. Participants were randomly allocated 12 of 48 ECGs, with an equal mix of correct and incorrect computer interpretation messages, and STEMI and STEMI-mimics. The nature of the responses required a cross-classified multi-level model., Results: 254 paramedics consented into the study, 205 completing the first phase and 150 completing phase two. The adjusted OR for a correct paramedic interpretation, when the computer interpretation was correct (true positive for STEMI or true negative for STEMI-mimic), was 1.80 (95% CI 0.84 to 4.91) and 0.58 (95% CI 0.41 to 0.81) when the computer interpretation was incorrect (false positive for STEMI or false negative for STEMI-mimic). The intraclass correlation coefficient for correct computer interpretations was 0.33 for participants and 0.17 for ECGs, and for incorrect computer interpretations, 0.06 for participants and 0.01 for ECGs., Conclusions: Determining the effect of computer interpretation messages using a web-based assessment tool is feasible, but the design needs to take clustered data into account. Pilot data suggest that computer messages influence paramedic interpretation, improving accuracy when correct and worsening accuracy when incorrect., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/)

Background: There is little in-depth research into how patients feel about emergency medical trials, and what influences these feelings., Objectives: To investigate patients' feelings on taking part in emergency medical research, particularly trials conducted without prospective consent., Methods: Seventeen inpatients, all recently admitted with a medical emergency, were interviewed. Questions focused on feelings on taking part in hypothetical trials, particularly trials conducted with deferred consent., Results: Five main themes were identified. Level of trust in the medical profession-high levels of trust tended to correlate with willingness to participate in trials. Previous bad healthcare experiences tended to diminish trust. Concerns for personal well-being-patients identified a conflict between aversion to unknown side effects and desire for access to newer and potentially better treatments. Some would be less inclined to participate in research if they were severely unwell, some more so. Altruism-many cited the importance of helping to advance medical knowledge and of 'giving back to the health service'. Concerns over autonomy-some felt that deferred consent was a violation of personal autonomy. Uncertainty-many patients seemed to struggle to understand the more complex concepts discussed., Conclusions: Patients are broadly trusting, and open to participating in emergency medical trials, but want to be kept as informed as possible throughout the process. Willingness may be improved by providing more complete explanations, although this may be limited by the complexity of relevant concepts. Good communication and improved public understanding of clinical trials would likely increase acceptance of emergency care research., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/)

Background: Unspecified chest pain is an important and potentially avoidable cause of emergency hospital admission. We aimed to examine inter-hospital variation in admission rates with unspecified chest pain and identify population characteristics, services and technologies that might explain this variation., Methods: We used Hospital Episodes Statistics data from 152 acute trusts in England to calculate a direct standardised annual admission rate per 100,000 population for each trust. Regression analysis was used to identify factors explaining variation, first, using routinely available data relating to the hospital catchment area and service and then using responses to a survey of emergency department (ED) management., Results: The best predictors of admission rate using routine data were total beds per 1000 population (p=0.001), rapid access chest pain clinic (RACPC) attendances per year (p<0.001) and percentage of households in poverty (p=0.01). Including data from 105/142 (74%) survey responses, the best predictors of admission rate were total beds (p<0.001), RACPC attendances (p=0.001), mean ED waiting time (p=0.049) and percentage of households in poverty (p<0.001). All associations were positive (higher variable predicts higher rate) except ED waiting time. We found no significant associations between factors relating to acute chest pain management and admission rate., Conclusions: Hospitals with higher admission rates for unspecified chest pain have greater bed provision, more RACPC attendances and serve populations with a higher percentage of households in poverty. These findings may be explained by services responding to demand in populations with greater need. We found no evidence that chest pain management influenced admission rates., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.)

Hospital mortality rates could be useful indicators of quality of care, but careful statistical analysis is required to avoid erroneously attributing variation in mortality to differences in health care when it is actually due to differences in case mix. The summary hospital mortality indicator is currently used by the English National Health Service (NHS). It adjusts mortality rates up to 30 days after discharge for patient age, sex, type of admission, year of discharge, comorbidity, deprivation and diagnosis. Such risk-adjustment methods have been used to identify poor performance, most notably at mid-Staffordshire NHS Foundation Trust, but their use is subject to a number of limitations. Studies exploring whether variation in risk-adjusted mortality can be explained by variation in healthcare have reached conflicting conclusions. Furthermore, concerns have been raised that the proportion of preventable deaths among hospital admissions is too small to produce a reliable 'signal' in risk-adjusted mortality rates. This provides hospital managers, regulators and clinicians with a considerable dilemma. Variation in mortality rates cannot be ignored, as they might indicate unacceptable variation in healthcare and avoidable mortality, but they also cannot be reliably used to judge the quality of healthcare, based on current evidence., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.)

Pulmonary embolism (PE) is a leading cause of death in pregnancy and postpartum. Clinicians face a difficult choice when deciding whether to use diagnostic imaging to investigate for suspected PE in these patients, between risking potentially catastrophic consequences of missed diagnosis if imaging is withheld and risking unnecessary iatrogenic harm to both mother and fetus if imaging is overused. This paper explores the options for imaging and evidence for the use of clinical features, clinical predictions scores or biomarkers to select pregnant and postpartum women for imaging. It also considers where future research could be most appropriately directed., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.)

Introduction: Globally, there has been an increase in the prevalence and scale of disasters with low- and middle-income countries (LMICs) tending to be more affected. Consequently, disaster risk reduction has been advocated as a global priority. However, the evidence base for disaster management in these settings is unclear., Methods: This study is a scoping review of the evidence base for disaster management in LMIC. Potentially relevant articles between 1990 and 2011 were searched for, assessed for relevance and subsequently categorised using a thematic coding framework based on the US Integrated Emergency Management System model., Results: Out of 1545 articles identified, only 178 were from LMIC settings. Most were of less robust design such as event reports and commentaries, and 66% pertained to natural disasters. There was a paucity of articles on disaster mitigation or recovery, and more were written on disaster response and preparedness issues., Discussion: Considerably more articles were published from high-income country settings that may reflect a publication bias. Current grey literature on disaster management tends not to be peer reviewed, is not well organised and not easy to access. The paucity of peer-reviewed publications compromises evidence review initiatives that seek to provide an evidence-base for disaster management in LMIC. As such, there is an urgent need for greater research and publication of findings on disaster management issues from these settings., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.)

Introduction: Pain management in emergency departments (ED) is often inadequate despite the availability of effective analgesia, with many patients receiving insufficient and untimely analgesia. We conducted a systematic literature review to identify interventions that could improve pain management in the ED., Methods: We systematically searched seven databases for studies reporting pain management outcomes after intervention to change professional practice to improve pain management in the ED, compared with pain management before or without intervention. Data was synthesised using principles of narrative synthesis., Results: We identified 43 relevant studies, including 40 uncontrolled before-and-after studies. Interventions included implementation of guidelines and protocols, educational interventions, pain scoring tools and changes in nursing roles, with many multifaceted interventions incorporating two or more of these elements. Interventions aimed to improve assessment and documentation of pain, knowledge and awareness of pain management and reduce time to analgesia. Due to the high probability of bias in study design and significant variation between studies, it was not possible to estimate the overall effectiveness of interventions, or identify which had the greatest impact. Intervention to improve pain management was reported to have some positive impact in most studies, but these findings may be explained by limitations in study design., Conclusions: Many interventions reported improvements in pain management, but current evidence is insufficient to recommend any for widespread adoption. In order to improve pain management we need to understand more about the theory underlying interventions, the context in which interventions work, and develop interventions based on this stronger theoretical understanding., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.)

Background: Clinical assessment can be used to identify which patients with acute asthma are at risk of unsuccessful initial treatment., Objective: To determine which elements of clinical assessment predict unsuccessful treatment, defined as needing critical care or any unplanned additional treatment., Methods: We analysed data from a large multicentre trial (the 3Mg trial). Adults with severe acute asthma underwent standardised clinical assessment, including peak expiratory flow rate (PEFR), up to 2 h after initiation of treatment. Standard care was provided other than blinded random allocation to trial treatment or placebo. Patients were followed up by record review up to 30 days. Unsuccessful treatment was defined as needing (1) critical care or (2) critical care or any unplanned additional treatment within 7 days of presentation. Logistic regression was used to identify predictors and derive a prediction model for each outcome., Results: Out of 1084 patients analysed, 81 (7%) received critical care and 157 (14%) received critical care or unplanned additional treatment. Baseline PEFR (p=0.017), baseline heart rate (p<0.001), other serious illness (p=0.019), PEFR change (p=0.015) and heart rate change (p<0.001) predicted need for critical care. Baseline PEFR (p=0.010), baseline heart rate (p<0.001), baseline respiratory rate (p=0.017), other serious illness (p=0.023), PEFR change (p=0.003) and heart rate change (p=0.001) predicted critical care or additional treatment. Models based on these characteristics had c-statistics of 0.77 and 0.69, respectively., Conclusions: PEFR, heart rate and other serious illnesses are the best predictors of unsuccessful treatment, but models based on these variables provide modest predictive value., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.)

Background and Objective: Little is known about the expectations of patients attending the emergency department (ED) with minor injuries. Failure to address expectations may lead to dissatisfaction and poor compliance. We aimed to describe patient expectations of minor injury care and explore the association between unmet expectations and patient satisfaction., Methods: We undertook a cross-sectional questionnaire survey of 300 patients attending the ED with minor injuries on weekdays between 9:00 and 17:00. Participants completed a questionnaire asking which tests and treatments they expected, which they consequently received, whether explanations were given for tests and treatments, and how they rated satisfaction with care., Results: The most frequently expected interventions were x-ray, analgesia and bandage/strapping. In each case the proportion expecting intervention was significantly higher than the proportion receiving intervention: x-ray (58% vs 47%, p<0.001); analgesia (40% vs 20%, p<0.001); bandage/strapping (39% vs 22%, p<0.001). There were no significant differences between the proportions expecting and receiving other interventions. At least one unmet expectation was reported by 208/300 patients (69%) but an explanation was received in 151/208 cases (73%). Conversely, 106 (35%) received an unexpected intervention, of whom 79/106 (74%) received an explanation. Patients with unmet expectations tended to rate the satisfaction lower, but the difference was not statistically significant (p=0.187)., Conclusions: Patients often expect interventions for minor injuries that they do not receive, but in most cases an explanation was given. We were unable to demonstrate an association between unmet expectations and reduced satisfaction with care., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.)

Background: Clinical trials are required to strengthen the evidence base for prehospital care. This questionnaire study aimed to explore paramedics' perceptions of prehospital research and barriers to conducting prehospital clinical trials., Methods: A self-completed questionnaire was developed to explore paramedic perceptions and barriers to undertaking prehospital trials based upon a review of existing research and semistructured qualitative interviews with five paramedics. The questionnaire was distributed by 'research champions' to 300 paramedics at randomly selected ambulance stations in Yorkshire., Results: Responses were received from 96/300 participants (32%). Interest in clinical trials was reported, but barriers were recognised, including perceptions of poor knowledge and limited use of evidence, that conducting research is not a paramedics' responsibility, limited support for involvement in trials, concerns about the practicalities of randomisation and consent, and time pressures. No association was found between training route and perceived understanding of trials (p=0.263) or feeling that involvement in trials was a professional responsibility (p=0.838). Previous involvement in prehospital research was not associated with opinions on importance of an evidence base (p=0.934) or gaining consent (p=0.329). The number of years respondents had been practicing was not associated with opinions on personal experience versus scientific evidence (p=0.582) or willingness to receive training for clinical trials (p=0.111). However, the low response rate limited the power of the study to detect potential associations., Conclusions: Paramedics reported interest and understanding of research, but a number of practical and ethical barriers were recognised that need to be addressed if prehospital clinical trials are to increase., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.)

Background: Some emergency admissions can be avoided if acute exacerbations of health problems are managed by the range of health services providing emergency and urgent care., Aim: To identify system-wide factors explaining variation in age sex adjusted admission rates for conditions rich in avoidable admissions., Design: National ecological study., Setting: 152 emergency and urgent care systems in England., Methods: Hospital Episode Statistics data on emergency admissions were used to calculate an age sex adjusted admission rate for conditions rich in avoidable admissions for each emergency and urgent care system in England for 2008-2011., Results: There were 3 273 395 relevant admissions in 2008-2011, accounting for 22% of all emergency admissions. The mean age sex adjusted admission rate was 2258 per year per 100 000 population, with a 3.4-fold variation between systems (1268 and 4359). Factors beyond the control of health services explained the majority of variation: unemployment rates explained 72%, with urban/rural status explaining further variation (R(2)=75%). Factors related to emergency departments, hospitals, emergency ambulance services and general practice explained further variation (R(2)=85%): the attendance rate at emergency departments, percentage of emergency department attendances converted to admissions, percentage of emergency admissions staying less than a day, percentage of emergency ambulance calls not transported to hospital and perceived access to general practice within 48 h., Conclusions: Interventions to reduce avoidable admissions should be targeted at deprived communities. Better use of emergency departments, ambulance services and primary care could further reduce avoidable emergency admissions.

Objective: To examine the diagnostic accuracy of novel biomarkers of myocardial injury and troponin assays for diagnosis of myocardial infarction., Methods: 850 patients randomised to the point-of-care testing arm of the Randomised Assessment of Panel Assay of Cardiac markers (RATPAC) study in six emergency departments of low-risk patients presenting with chest pain were studied. Blood samples were obtained on admission and 90 min from admission. Myocardial infarction was defined by the universal definition of myocardial infarction. The following diagnostic strategies were compared by receiver operator characteristic curve analysis and comparison of area under the curve: individual marker values and the combination of presentation heart fatty acid binding protein (HFABP) and copeptin with troponin., Results: 68 patients had a final diagnosis of myocardial infarction. Admission samples were available from 838/1132 patients enrolled in the study. Areas under the curve were as follows (CIs in parentheses): cardiac troponin I (cTnI) Stratus CS 0.94 (0.90 to 0.98), cTnI Beckmann 0.92 (0.88 to 0.96), cTnI Siemens ultra 0.90 (0.85 to 0.95), cardiac troponin T high sensitivity 0.92 (0.88 to 0.96), HFABP 1 0.84 (0.77 to 0.90) copeptin 0.62 (0.57 to 0.68). HFABP and copeptin were diagnostically inferior to troponin. The combination of HFABP (at the 95th percentile) and troponin (at the 99th percentile) increased diagnostic sensitivity., Conclusions: High-sensitivity cardiac troponin is the best single marker. Addition of HFABP to high-sensitivity troponin increased diagnostic sensitivity. Additional measurement of copeptin is not useful in the chest pain population.

Objectives: Information technology (IT) has an important role in the emergency department (ED) functioning, but staff attitudes can influence the way IT is used. Qualitative research into the perceptions of the ED staff has identified a variety of individual, environmental and system factors that may influence attitudes towards using IT. The authors aimed to determine which factors predict attitudes towards using IT and which factors are the most influential., Methods: Findings from a previous qualitative study were used to develop a self-administered questionnaire measuring individual, environmental and system factors, along with staff attitudes towards using IT. The questionnaire was sent to 535 staff working in three English EDs. Simple linear regression was used to examine the relationship between each potential predictor and user attitude, and multiple regression was used to identify the most important predictors., Results: Completed questionnaires were returned by 362/535 participants (68%). The factors with the strongest positive association with staff attitudes towards using IT were the perceived individual impact of technology (r(2)=39%, p<0.001), perceived usefulness (r(2)=7%, p<0.001), perceived ease of use (r(2)=2%, p=0.006), perceived subjective norms (r(2)=1%, p=0.013) and computer experience (r(2)=1%, p=0.034)., Conclusion: The perceived individual impact of technology is the most important factor in determining ED staff attitude towards using IT. The ED staff are more likely to view using IT systems positively if they can see direct individual benefits arising from their use.

Background: Heart-type fatty acid binding protein (H-FABP) has been proposed as an early biomarker of myocardial infarction (MI). The authors aimed to undertake a systematic review and meta-analysis to estimate the early sensitivity and specificity of quantitative and qualitative H-FABP assays., Methods: The authors undertook a systematic search using electronic databases, citation lists and expert contacts to identify all diagnostic cohort studies of patients presenting with suspected acute coronary syndrome that compared H-FABP at presentation to a reference standard based on the Universal definition of MI. Study quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies tool. Meta-analysis was conducted using Bayesian Markov chain Monte Carlo simulation., Results: The authors included eight studies of quantitative H-FABP and nine studies of qualitative H-FABP. The summary estimates of sensitivity and specificity were 81% (95% prediction interval 50% to 95%) and 80% (26% to 98%) respectively for the quantitative assays and 68% (11% to 97%) and 92% (20% to 100%) respectively for the qualitative assays. Four studies reported the sensitivity of troponin and H-FABP at presentation in which the combination was considered positive if either test was positive. The addition of H-FABP to troponin increased sensitivity from 42-75% to 76-97% but decreased specificity from 94-100% to 65-93%., Conclusion: H-FABP has modest sensitivity and specificity for MI at presentation but estimates are subject to substantial uncertainty and primary data are subject to substantial heterogeneity. H-FABP may have a role alongside troponin in improving early sensitivity but comparison with high sensitivity troponin assays is required.