Major Trauma Triage Tool Study (MATTS) expert consensus-derived injury assessment tool.

Introduction: Major trauma centre (MTC) care has been associated with improved outcomes for injured patients. English ambulance services and trauma networks currently use a range of triage tools to select patients for bypass to MTCs. A standardised national triage tool may improve triage accuracy, cost-effectiveness and the reproducibility of decision-making. Methods: We conducted an expert consensus process to derive and develop a major trauma triage tool for use in English trauma networks. A web-based Delphi survey was conducted to identify and confirm candidate triage tool predictors of major trauma. Facilitated roundtable consensus meetings were convened to confirm the proposed triage tool's purpose, target diagnostic threshold, scope, intended population and structure, as well as the individual triage tool predictors and cut points. Public and patient involvement (PPI) focus groups were held to ensure triage tool acceptability to service users. Results: The Delphi survey reached consensus on nine triage variables in two domains, from 109 candidate variables after three rounds. Following a review of the relevant evidence during the consensus meetings, iterative rounds of discussion achieved consensus on the following aspects of the triage tool: reference standard, scope, target diagnostic accuracy and intended population. A three-step tool comprising physiology, anatomical injury and clinical judgement domains, with triage variables assessed in parallel, was recommended. The triage tool was received favourably by PPI focus groups. Conclusions: This paper presents a new expert consensus derived major trauma triage tool with defined purpose, scope, intended population, structure, constituent variables, variable definitions and thresholds. Prospective evaluation is required to determine clinical and cost-effectiveness, acceptability and usability.

Evaluation of venous thromboembolism risk assessment models for hospital inpatients: the VTEAM evidence synthesis.

Background: Pharmacological prophylaxis during hospital admission can reduce the risk of acquired blood clots (venous thromboembolism) but may cause complications, such as bleeding. Using a risk assessment model to predict the risk of blood clots could facilitate selection of patients for prophylaxis and optimise the balance of benefits, risks and costs. Objectives: We aimed to identify validated risk assessment models and estimate their prognostic accuracy, evaluate the cost-effectiveness of different strategies for selecting hospitalised patients for prophylaxis, assess the feasibility of using efficient research methods and estimate key parameters for future research. Design: We undertook a systematic review, decision-analytic modelling and observational cohort study conducted in accordance with Enhancing the QUAlity and Transparency Of health Research (EQUATOR) guidelines. Setting: NHS hospitals, with primary data collection at four sites. Participants: Medical and surgical hospital inpatients, excluding paediatric, critical care and pregnancy-related admissions. Interventions: Prophylaxis for all patients, none and according to selected risk assessment models. Main outcome measures: Model accuracy for predicting blood clots, lifetime costs and quality-adjusted life-years associated with alternative strategies, accuracy of efficient methods for identifying key outcomes and proportion of inpatients recommended prophylaxis using different models. Results: We identified 24 validated risk assessment models, but low-quality heterogeneous data suggested weak accuracy for prediction of blood clots and generally high risk of bias in all studies. Decision-analytic modelling showed that pharmacological prophylaxis for all eligible is generally more cost-effective than model-based strategies for both medical and surgical inpatients, when valuing a quality-adjusted life-year at £20,000. The findings were more sensitive to uncertainties in the surgical population; strategies using risk assessment models were more cost-effective if the model was assumed to have a very high sensitivity, or the long-term risks of post-thrombotic complications were lower. Efficient methods using routine data did not accurately identify blood clots or bleeding events and several pre-specified feasibility criteria were not met. Theoretical prophylaxis rates across an inpatient cohort based on existing risk assessment models ranged from 13% to 91%. Limitations: Existing studies may underestimate the accuracy of risk assessment models, leading to underestimation of their cost-effectiveness. The cost-effectiveness findings do not apply to patients with an increased risk of bleeding. Mechanical thromboprophylaxis options were excluded from the modelling. Primary data collection was predominately retrospective, risking case ascertainment bias. Conclusions: Thromboprophylaxis for all patients appears to be generally more cost-effective than using a risk assessment model, in hospitalised patients at low risk of bleeding. To be cost-effective, any risk assessment model would need to be highly sensitive. Current evidence on risk assessment models is at high risk of bias and our findings should be interpreted in this context. We were unable to demonstrate the feasibility of using efficient methods to accurately detect relevant outcomes for future research. Future work: Further research should evaluate routine prophylaxis strategies for all eligible hospitalised patients. Models that could accurately identify individuals at very low risk of blood clots (who could discontinue prophylaxis) warrant further evaluation. Study registration: This study is registered as PROSPERO CRD42020165778 and Researchregistry5216. Funding: This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: NIHR127454) and will be published in full in Health Technology Assessment; Vol. 28, No. 20. See the NIHR Funding and Awards website for further award information.

People who are admitted to hospital are at risk of blood clots that can cause serious illness or death. Patients are often given low doses of blood-thinning drugs to reduce this risk. However, these drugs can cause side effects, such as bleeding. Hospitals currently use complex risk assessment models (risk scores, which usually include patient, disease, mobility and intervention factors) to determine the individual risk of blood clots and identify people most likely to benefit from blood-thinning drugs. There are a lot of different risk scores and we do not know which one is best. We also do not know how these scores compare to each other or whether using scores to decide who should get blood-thinning drugs provides good value for money to the NHS. We reviewed all previous studies of risk scores. We found that they did not predict blood clots very well and we could not recommend one score over another. We then created a mathematical model to simulate the use of blood-thinning drugs in people admitted to hospital. The model suggested that giving blood-thinning drugs to everyone who could have them would probably provide the best value for money, in medical patients. Our findings were the same, but less certain, for surgical patients. We also collected information from four NHS hospitals to explore possibilities for future research. Our work showed that routinely collected electronic data on blood clots and bleeding events is not very accurate and that using different scores could result in variable use of blood-thinning medications. Our findings suggest that it may be better value to the NHS and better for patients if we were to offer blood-thinning medications to everyone on admission to hospital, without using any risk score. However, this approach needs further research to ensure it is safe and effective. Such research would not be able to rely on routine electronic data to identify blood clots or bleeding events, in isolation.

Prehospital early warning scores for adults with suspected sepsis: the PHEWS observational cohort and decision-analytic modelling study.

Background: Guidelines for sepsis recommend treating those at highest risk within 1 hour. The emergency care system can only achieve this if sepsis is recognised and prioritised. Ambulance services can use prehospital early warning scores alongside paramedic diagnostic impression to prioritise patients for treatment or early assessment in the emergency department. Objectives: To determine the accuracy, impact and cost-effectiveness of using early warning scores alongside paramedic diagnostic impression to identify sepsis requiring urgent treatment. Design: Retrospective diagnostic cohort study and decision-analytic modelling of operational consequences and cost-effectiveness. Setting: Two ambulance services and four acute hospitals in England. Participants: Adults transported to hospital by emergency ambulance, excluding episodes with injury, mental health problems, cardiac arrest, direct transfer to specialist services, or no vital signs recorded. Interventions: Twenty-one early warning scores used alongside paramedic diagnostic impression, categorised as sepsis, infection, non-specific presentation, or other specific presentation. Main outcome measures: Proportion of cases prioritised at the four hospitals; diagnostic accuracy for the sepsis-3 definition of sepsis and receiving urgent treatment (primary reference standard); daily number of cases with and without sepsis prioritised at a large and a small hospital; the minimum treatment effect associated with prioritisation at which each strategy would be cost-effective, compared to no prioritisation, assuming willingness to pay £20,000 per quality-adjusted life-year gained. Results: Data from 95,022 episodes involving 71,204 patients across four hospitals showed that most early warning scores operating at their pre-specified thresholds would prioritise more than 10% of cases when applied to non-specific attendances or all attendances. Data from 12,870 episodes at one hospital identified 348 (2.7%) with the primary reference standard. The National Early Warning Score, version 2 (NEWS2), had the highest area under the receiver operating characteristic curve when applied only to patients with a paramedic diagnostic impression of sepsis or infection (0.756, 95% confidence interval 0.729 to 0.783) or sepsis alone (0.655, 95% confidence interval 0.63 to 0.68). None of the strategies provided high sensitivity (> 0.8) with acceptable positive predictive value (> 0.15). NEWS2 provided combinations of sensitivity and specificity that were similar or superior to all other early warning scores. Applying NEWS2 to paramedic diagnostic impression of sepsis or infection with thresholds of > 4, > 6 and > 8 respectively provided sensitivities and positive predictive values (95% confidence interval) of 0.522 (0.469 to 0.574) and 0.216 (0.189 to 0.245), 0.447 (0.395 to 0.499) and 0.274 (0.239 to 0.313), and 0.314 (0.268 to 0.365) and 0.333 (confidence interval 0.284 to 0.386). The mortality relative risk reduction from prioritisation at which each strategy would be cost-effective exceeded 0.975 for all strategies analysed. Limitations: We estimated accuracy using a sample of older patients at one hospital. Reliable evidence was not available to estimate the effectiveness of prioritisation in the decision-analytic modelling. Conclusions: No strategy is ideal but using NEWS2, in patients with a 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. Research is needed to develop better definition, diagnosis and treatments for sepsis. Study registration: This study is registered as Research Registry (reference: researchregistry5268). Funding: This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: 17/136/10) and is published in full in Health Technology Assessment; Vol. 28, No. 16. See the NIHR Funding and Awards website for further award information.

Sepsis is a life-threatening condition in which an abnormal response to infection causes heart, lung or kidney failure. People with sepsis need urgent treatment. They need to be prioritised at the emergency department rather than waiting in the queue. Paramedics attempt to identify people with possible sepsis using an early warning score (based on simple measurements, such as blood pressure and heart rate) alongside their impression of the patient's diagnosis. They can then alert the hospital to assess the patient quickly. However, an inaccurate early warning score might miss cases of sepsis or unnecessarily prioritise people without sepsis. We aimed to measure how accurately early warning scores identified people with sepsis when used alongside paramedic diagnostic impression. We collected data from 71,204 people that two ambulance services transported to four different hospitals in 2019. We recorded paramedic diagnostic impressions and calculated early warning scores for each patient. At one hospital, we linked ambulance records to hospital records and identified who had sepsis. We then calculated the accuracy of using the scores alongside diagnostic impression to diagnose sepsis. Finally, we used modelling to predict how many patients (with and without sepsis) paramedics would prioritise using different strategies based on early warning scores and diagnostic impression. We found that none of the currently available early warning scores were ideal. When they were applied to all patients, they prioritised too many people. When they were only applied to patients whom the paramedics thought had infection, they missed many cases of sepsis. The NEWS2, score, which ambulance services already use, was as good as or better than all the other scores we studied. We found that using the NEWS2, score in people with a paramedic impression of infection could achieve a reasonable balance between prioritising too many patients and avoiding missing patients with sepsis.

Thromboprophylaxis during pregnancy and the puerperium: a systematic review and economic evaluation to estimate the value of future research.

Background: Pharmacological prophylaxis to prevent venous thromboembolism is currently recommended for women assessed as being at high risk of venous thromboembolism during pregnancy or in the 6 weeks after delivery (the puerperium). The decision to provide thromboprophylaxis involves weighing the benefits, harms and costs, which vary according to the individual's venous thromboembolism risk. It is unclear whether the United Kingdom's current risk stratification approach could be improved by further research. Objectives: To quantify the current decision uncertainty associated with selecting women who are pregnant or in the puerperium for thromboprophylaxis and to estimate the value of one or more potential future studies that would reduce that uncertainty, while being feasible and acceptable to patients and clinicians. Methods: A decision-analytic model was developed which was informed by a systematic review of risk assessment models to predict venous thromboembolism in women who are pregnant or in the puerperium. Expected value of perfect information analysis was used to determine which factors are associated with high decision uncertainty and should be the target of future research. To find out whether future studies would be acceptable and feasible, we held workshops with women who have experienced a blood clot or have been offered blood-thinning drugs and surveyed healthcare professionals. Expected value of sample information analysis was used to estimate the value of potential future research studies. Results: The systematic review included 17 studies, comprising 19 unique externally validated risk assessment models and 1 internally validated model. Estimates of sensitivity and specificity were highly variable ranging from 0% to 100% and 5% to 100%, respectively. Most studies had unclear or high risk of bias and applicability concerns. The decision analysis found that there is substantial decision uncertainty regarding the use of risk assessment models to select high-risk women for antepartum prophylaxis and obese postpartum women for postpartum prophylaxis. The main source of decision uncertainty was uncertainty around the effectiveness of thromboprophylaxis for preventing venous thromboembolism in women who are pregnant or in the puerperium. We found that a randomised controlled trial of thromboprophylaxis in obese postpartum women is likely to have substantial value and is more likely to be acceptable and feasible than a trial recruiting women who have had a previous venous thromboembolism. In unselected postpartum women and women following caesarean section, the poor performance of risk assessment models meant that offering prophylaxis based on these models had less favourable cost effectiveness with lower decision uncertainty. Limitations: The performance of the risk assessment model for obese postpartum women has not been externally validated. Conclusions: Future research should focus on estimating the efficacy of pharmacological thromboprophylaxis in pregnancy and the puerperium, and clinical trials would be more acceptable in women who have not had a previous venous thromboembolism. Study registration: This study is registered as PROSPERO CRD42020221094. Funding: This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: NIHR131021) and is published in full in Health Technology Assessment; Vol. 28, No. 9. See the NIHR Funding and Awards website for further award information.

Women who are pregnant or who have given birth in the previous 6 weeks are at increased risk of developing blood clots that can cause serious illness or death. Small doses of blood thinners given by injection are safe in pregnancy and can reduce the risk of blood clots, but they can slightly increase the risk of bleeding. Healthcare professionals use risk assessment tools to decide if a woman is at high risk of blood clots and should be offered blood thinners. We wanted to find out what research would be useful to help them make better decisions. We reviewed previous research to establish which risk assessment tools are best at predicting who will have a blood clot. We then created a mathematical model to predict what would happen when using different risk assessment tools to decide who should be offered blood thinners, both during pregnancy and after giving birth. We found that there was a lot of uncertainty about which women should be offered blood thinners. This was mainly because there have only been a few small studies comparing blood thinners to no treatment in pregnant women or women who have recently given birth. We estimated the value of future studies comparing blood thinners to no treatment, in groups of women with different risk factors, by predicting what information we would gain and how this would be used to improve decisions about using blood thinners. To find out whether these studies would be acceptable and feasible, we held workshops with women who have experienced a blood clot or have been offered blood thinners and surveyed healthcare professionals. We found that a study in obese women who have recently given birth would have substantial value and may be more acceptable than a study in pregnant women with a previous blood clot.

Effectiveness and cost effectiveness of pharmacological thromboprophylaxis for medical inpatients: decision analysis modelling study.

Objective: To determine the balance of costs, risks, and benefits for different thromboprophylaxis strategies for medical patients during hospital admission. Design: Decision analysis modelling study. Setting: NHS hospitals in England. Population: Eligible adult medical inpatients, excluding patients in critical care and pregnant women. Interventions: Pharmacological thromboprophylaxis (low molecular weight heparin) for all medical inpatients, thromboprophylaxis for none, and thromboprophylaxis given to higher risk inpatients according to risk assessment models (Padua, Caprini, IMPROVE, Intermountain, Kucher, Geneva, and Rothberg) previously validated in medical cohorts. Main outcome measures: Lifetime costs and quality adjusted life years (QALYs). Costs were assessed from the perspective of the NHS and Personal Social Services in England. Other outcomes assessed were incidence and treatment of venous thromboembolism, major bleeds including intracranial haemorrhage, chronic thromboembolic complications, and overall survival. Results: Offering thromboprophylaxis to all medical inpatients had a high probability (>99%) of being the most cost effective strategy (at a threshold of £20 000 (€23 440; $25 270) per QALY) in the probabilistic sensitivity analysis, when applying performance data from the Padua risk assessment model, which was typical of that observed across several risk assessment models in a medical inpatient cohort. Thromboprophylaxis for all medical inpatients was estimated to result in 0.0552 additional QALYs (95% credible interval 0.0209 to 0.1111) while generating cost savings of £28.44 (-£47 to £105) compared with thromboprophylaxis for none. No other risk assessment model was more cost effective than thromboprophylaxis for all medical inpatients when assessed in deterministic analysis. Risk based thromboprophylaxis was found to have a high (76.6%) probability of being the most cost effective strategy only when assuming a risk assessment model with very high sensitivity is available (sensitivity 99.9% and specificity 23.7% v base case sensitivity 49.3% and specificity 73.0%). Conclusions: Offering pharmacological thromboprophylaxis to all eligible medical inpatients appears to be the most cost effective strategy. To be cost effective, any risk assessment model would need to have a very high sensitivity resulting in widespread thromboprophylaxis in all patients except those at the very lowest risk, who could potentially avoid prophylactic anticoagulation during their hospital stay.

Building an understanding of Ethnic minority people's Service Use Relating to Emergency care for injuries: the BE SURE study protocol.

INTRODUCTION: Injuries are a major public health problem which can lead to disability or death. However, little is known about the incidence, presentation, management and outcomes of emergency care for patients with injuries among people from ethnic minorities in the UK. The aim of this study is to investigate what may differ for people from ethnic minorities compared with white British people when presenting with injury to ambulance and Emergency Departments (EDs). METHODS AND ANALYSIS: This mixed methods study covers eight services, four ambulance services (three in England and one in Scotland) and four hospital EDs, located within each ambulance service. The study has five Work Packages (WP): (WP1) scoping review comparing mortality by ethnicity of people presenting with injury to emergency services; (WP2) retrospective analysis of linked NHS routine data from patients who present to ambulances or EDs with injury over 5 years (2016-2021); (WP3) postal questionnaire survey of 2000 patients (1000 patients from ethnic minorities and 1000 white British patients) who present with injury to ambulances or EDs including self-reported outcomes (measured by Quality of Care Monitor and Health Related Quality of Life measured by SF-12); (WP4) qualitative interviews with patients from ethnic minorities (n=40) and focus groups-four with asylum seekers and refugees and four with care providers and (WP5) a synthesis of quantitative and qualitative findings. ETHICS AND DISSEMINATION: This study received a favourable opinion by the Wales Research Ethics Committee (305391). The Health Research Authority has approved the study and, on advice from the Confidentiality Advisory Group, has supported the use of confidential patient information without consent for anonymised data. Results will be shared with ambulance and ED services, government bodies and third-sector organisations through direct communications summarising scientific conference proceedings and publications.

Decision-analysis modeling of effectiveness and cost-effectiveness of pharmacologic thromboprophylaxis for surgical inpatients using variable risk assessment models or other strategies.

BACKGROUND: Surgical inpatients are at a risk of venous thromboembolism (VTE), which can be life-threatening or result in chronic complications. Thromboprophylaxis reduces the VTE risk but incurs costs and may increase bleeding risk. Risk assessment models (RAMs) are currently used to target thromboprophylaxis at high-risk patients. OBJECTIVES: To determine the balance of cost, risk, and benefit for different thromboprophylaxis strategies in adult surgical inpatients, excluding patients who underwent major orthopedic surgery or were under critical care and pregnant women. METHODS: Decision analytic modeling was performed to estimate the following outcomes for alternative thromboprophylaxis strategies: thromboprophylaxis usage; VTE incidence and treatment; major bleeding; chronic thromboembolic complications; and overall survival. Strategies compared were as follows: no thromboprophylaxis; thromboprophylaxis for all; and thromboprophylaxis given according to RAMs (Caprini and Pannucci). Thromboprophylaxis is assumed to be given for the duration of hospitalization. The model evaluates lifetime costs and quality-adjusted life-years (QALYs) within England's health and social care services. RESULTS: Thromboprophylaxis for all surgical inpatients had a 70% probability of being the most cost-effective strategy (at a £20 000 per QALY threshold). RAM-based prophylaxis would be the most cost-effective strategy if a RAM with a higher sensitivity (99.9%) were available for surgical inpatients. QALY gains were mainly due to reduced postthrombotic complications. The optimal strategy was sensitive to several other factors such as the risk of VTE, bleeding and postthrombotic syndrome, duration of prophylaxis, and patient age. CONCLUSION: Thromboprophylaxis for all eligible surgical inpatients seemed to be the most cost-effective strategy. Default recommendations for pharmacologic thromboprophylaxis, with the potential to opt-out, may be superior to a complex risk-based opt-in approach.

Multicentre open label randomised controlled trial of immediate enhanced ambulatory ECG monitoring versus standard monitoring in acute unexplained syncope patients: the ASPIRED study.

INTRODUCTION: Diagnosing underlying arrhythmia in emergency department (ED) syncope patients is difficult. There is a evidence that diagnostic yield for detecting underlying arrhythmia is highest when cardiac monitoring devices are applied early, ideally at the index visit. This strategy has the potential to change current syncope management from low diagnostic yield Holter to higher yield ambulatory monitoring, reduce episodes of syncope, reduce risk of recurrence and its potential serious consequences, reduce hospital admissions, reduce overall health costs and increase quality of life by allowing earlier diagnosis, treatment and exclusion of clinically important arrhythmias. METHODS AND ANALYSES: This is a UK open prospective parallel group multicentre randomised controlled trial of an immediate 14-day ambulatory patch heart monitor vs standard care in 2234 patients presenting acutely with unexplained syncope. Our patient focused primary endpoint will be number of episodes of syncope at 1 year. Health economic evaluation will estimate the incremental cost per syncope episode avoided and quality-adjusted life year gained. ETHICS AND DISSEMINATION: Informed consent for participation will be sought. The ASPIRED trial received a favourable ethical opinion from South East Scotland Research Ethics Committee 01 (21/SS/0073). Results will be disseminated via scientific publication, lay summary and visual abstract. TRIAL REGISTRATION NUMBER: ISRCTN 10278811.

Cost-effectiveness of rapid assessment of potential ischaemic heart disease with CT coronary angiography.

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.

Risk assessment models for venous thromboembolism in pregnancy and in the puerperium: a systematic review.

OBJECTIVES: To assess the comparative accuracy of risk assessment models (RAMs) to identify women during pregnancy and the early postnatal period who are at increased risk of venous thromboembolism (VTE). DESIGN: Systematic review following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. DATA SOURCES: MEDLINE, Embase, Cochrane Library and two research registers were searched until February 2021. ELIGIBILITY CRITERIA: All validation studies that examined the accuracy of a multivariable RAM (or scoring system) for predicting the risk of developing VTE in women who are pregnant or in the puerperium (within 6 weeks post-delivery). DATA EXTRACTION AND SYNTHESIS: Two authors independently selected and extracted data. Risk of bias was appraised using PROBAST (Prediction model Risk Of Bias ASsessment Tool). Data were synthesised without meta-analysis. RESULTS: Seventeen studies, comprising 19 externally validated RAMs and 1 internally validated model, met the inclusion criteria. The most widely evaluated RAMs were the Royal College of Obstetricians and Gynaecologists guidelines (six studies), American College of Obstetricians and Gynecologists guidelines (two studies), Swedish Society of Obstetrics and Gynecology guidelines (two studies) and the Lyon score (two studies). In general, estimates of sensitivity and specificity were highly variable with sensitivity estimates ranging from 0% to 100% for RAMs that were applied to antepartum women to predict antepartum or postpartum VTE and 0% to 100% for RAMs applied postpartum to predict postpartum VTE. Specificity estimates were similarly diverse ranging from 28% to 98% and 5% to 100%, respectively. CONCLUSIONS: Available data suggest that external validation studies have weak designs and limited generalisability, so estimates of prognostic accuracy are very uncertain. PROSPERO REGISTRATION NUMBER: CRD42020221094.

Early computed tomography coronary angiography in adults presenting with suspected acute coronary syndrome: the RAPID-CTCA RCT.

BACKGROUND: Acute coronary syndrome is a common medical emergency. The optimal strategy to investigate patients who are at intermediate risk of acute coronary syndrome has not been fully determined. OBJECTIVE: To investigate the role of early computed tomography coronary angiography in the investigation and treatment of adults presenting with suspected acute coronary syndrome. DESIGN: A prospective, multicentre, open, parallel-group randomised controlled trial with blinded end-point adjudication. SETTING: Thirty-seven hospitals in the UK. PARTICIPANTS: Adults (aged ≥ 18 years) presenting to the emergency department, acute medicine services or cardiology department with suspected or provisionally diagnosed acute coronary syndrome and at least one of the following: (1) a prior history of coronary artery disease, (2) a cardiac troponin level > 99th centile and (3) an abnormal 12-lead electrocardiogram. INTERVENTIONS: Early computed tomography coronary angiography in addition to standard care was compared with standard care alone. Participants were followed up for 1 year. MAIN OUTCOME MEASURE: One-year all-cause death or subsequent type 1 (spontaneous) or type 4b (stent thrombosis) myocardial infarction, measured as the time to such event adjudicated by two cardiologists blinded to the computerised tomography coronary angiography ( CTCA ) arm. Cost-effectiveness was estimated as the lifetime incremental cost per quality-adjusted life-year gained. RESULTS: Between 23 March 2015 and 27 June 2019, 1748 participants [mean age 62 years (standard deviation 13 years), 64% male, mean Global Registry Of Acute Coronary Events score 115 (standard deviation 35)] were randomised to receive early computed tomography coronary angiography (n = 877) or standard care alone (n = 871). The primary end point occurred in 51 (5.8%) participants randomised to receive computed tomography coronary angiography and 53 (6.1%) participants randomised to receive standard care (adjusted hazard ratio 0.91, 95% confidence interval 0.62 to 1.35; p = 0.65). Computed tomography coronary angiography was associated with a reduced use of invasive coronary angiography (adjusted hazard ratio 0.81, 95% confidence interval 0.72 to 0.92; p = 0.001) but no change in coronary revascularisation (adjusted hazard ratio 1.03, 95% confidence interval 0.87 to 1.21; p = 0.76), acute coronary syndrome therapies (adjusted odds ratio 1.06, 95% confidence interval 0.85 to 1.32; p = 0.63) or preventative therapies on discharge (adjusted odds ratio 1.07, 95% confidence interval 0.87 to 1.32; p = 0.52). Early computed tomography coronary angiography was associated with longer hospitalisations (median increase 0.21 days, 95% confidence interval 0.05 to 0.40 days) and higher mean total health-care costs over 1 year (£561 more per patient) than standard care. LIMITATIONS: The principal limitation of the trial was the slower than anticipated recruitment, leading to a revised sample size, and the requirement to compromise and accept a larger relative effect size estimate for the trial intervention. FUTURE WORK: The potential role of computed tomography coronary angiography in selected patients with a low probability of obstructive coronary artery disease (intermediate or mildly elevated level of troponin) or who have limited access to invasive cardiac catheterisation facilities needs further prospective evaluation. CONCLUSIONS: In patients with suspected or provisionally diagnosed acute coronary syndrome, computed tomography coronary angiography did not alter overall coronary therapeutic interventions or 1-year clinical outcomes, but it did increase the length of hospital stay and health-care costs. These findings do not support the routine use of early computed tomography coronary angiography in intermediate-risk patients with acute chest pain. TRIAL REGISTRATION: This trial is registered as ISRCTN19102565 and Clinical Trials NCT02284191. FUNDING: This project was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 26, No. 37. See the NIHR Journals Library website for further project information.

WHY DID WE DO THE RESEARCH?: Chest pain is a common medical emergency. It is important to decide if the cause is a heart attack. The two tests that are often used are a heart recording (electrocardiogram) and a blood test (troponin levels). If both are normal, the cause of chest pain is unlikely to be a heart attack and the patient is often discharged home. If either test is positive or if the patient has had previous heart problems, then the patient may require further investigation. We wanted to test whether or not adding a heart scan called a computerised tomography coronary angiogram improved patients' care. HOW DID WE DO THE RESEARCH?: We carried out a randomised trial in which half of the patients attending hospital with chest pain had a computerised tomography coronary angiography scan as part of their assessment and half of the patients did not. In total, 1749 patients were recruited and followed up for 1 year. BRINGING IT ALL TOGETHER: The use of an additional early computerised tomography coronary angiography scan for chest pain patients of medium risk produced only small improvements in patient care.

Clinical and cost-effectiveness of paramedic administered fascia iliaca compartment block for emergency hip fracture (RAPID 2)-protocol for an individually randomised parallel-group trial.

BACKGROUND: Approximately 75,000 people fracture a hip each year in the UK. This painful injury can be devastating-with a high associated mortality rate-and survivors likely to be more dependent and less mobile. Pain relief at the scene of injury is known to be inadequate. Intravenous morphine is usually given by paramedics, but opioids are less effective for dynamic pain and can cause serious side effects, including nausea, constipation, delirium and respiratory depression. These may delay surgery, require further treatment and worsen patient outcomes. We completed a feasibility study of paramedic-provided fascia iliaca compartment block (FICB), testing the intervention, trial methods and data collection. The study (RAPID) demonstrated that a full trial was feasible. In this subsequent study, we aim to test safety, clinical and cost-effectiveness of paramedic-provided FICB as pain relief to patients with suspected hip fracture in the prehospital environment. METHODS: We will conduct a pragmatic multi-centre individually randomised parallel-group trial, with a 1:1 allocation between usual care (control) and FICB (intervention). Hospital clinicians in five sites (paired ambulance services and receiving hospitals) in England and Wales will train 220 paramedics to administer FICB. The primary outcome is change in pain score from pre-randomisation to arrival at the emergency department. One thousand four hundred patients are required to find a clinically important difference between trial arms in the primary outcome (standardised statistical effect ~ 0.2; 90% power, 5% significance). We will use NHS Digital (England) and the SAIL (Secure Anonymised Information Linkage) databank (Wales) to follow up patient outcomes using routine anonymised linked data in an efficient study design, and questionnaires to capture patient-reported outcomes at 1 and 4 months. Secondary outcomes include mortality, length of hospital stay, job cycle time, prehospital medications including morphine, presence of hip fracture, satisfaction, mobility, and NHS costs. We will assess safety by monitoring serious adverse events (SAEs). DISCUSSION: The trial will help to determine whether paramedic administered FICB is a safe, clinically and cost-effective treatment for suspected hip fracture in the pre-hospital setting. Impact will be shown if and when clinical guidelines either recommend or reject the use of FICB in routine practice in this context. TRIAL REGISTRATION: ISRCTN15831813 . Registered on 22 September 2021.

An economic evaluation of triage tools for patients with suspected severe injuries in England.

BACKGROUND: Many health care systems triage injured patients to major trauma centres (MTCs) or local hospitals by using triage tools and paramedic judgement. Triage tools are typically assessed by whether patients with an Injury Severity Score (ISS) ≥ 16 go to an MTC and whether patients with an ISS < 16 are sent to their local hospital. There is a trade-off between sensitivity and specificity of triage tools, with the optimal balance being unknown. We conducted an economic evaluation of major trauma triage tools to identify which tool would be considered cost-effective by UK decision makers. METHODS: A patient-level, probabilistic, mathematical model of a UK major trauma system was developed. Patients with an ISS ≥ 16 who were only treated at local hospitals had worse outcomes compared to being treated in an MTC. Nine empirically derived triage tools, from a previous study, were examined so we assessed triage tools with realistic trade-offs between triage tool sensitivity and specificity. Lifetime costs, lifetime quality adjusted life years (QALYs), and incremental cost-effectiveness ratios (ICERs) were calculated for each tool and compared to maximum acceptable ICERs (MAICERs) in England. RESULTS: Four tools had ICERs within the normal range of MAICERs used by English decision makers (£20,000 to £30,000 per QALY gained). A low sensitivity (28.4%) and high specificity (88.6%) would be cost-effective at the lower end of this range while higher sensitivity (87.5%) and lower specificity (62.8%) was cost-effective towards the upper end of this range. These results were sensitive to the cost of MTC admissions and whether MTCs had a benefit for patients with an ISS between 9 and 15. CONCLUSIONS: The cost-effective triage tool depends on the English decision maker's MAICER for this health problem. In the usual range of MAICERs, cost-effective prehospital trauma triage involves clinically suboptimal sensitivity, with a proportion of seriously injured patients (at least 10%) being initially transported to local hospitals. High sensitivity trauma triage requires development of more accurate decision rules; research to establish if patients with an ISS between 9 and 15 benefit from MTCs; or, inefficient use of health care resources to manage patients with less serious injuries at MTCs.

Risk assessment models for venous thromboembolism in hospitalised adult patients: a systematic review.

INTRODUCTION: Hospital-acquired thrombosis accounts for a large proportion of all venous thromboembolism (VTE), with significant morbidity and mortality. This subset of VTE can be reduced through accurate risk assessment and tailored pharmacological thromboprophylaxis. This systematic review aimed to determine the comparative accuracy of risk assessment models (RAMs) for predicting VTE in patients admitted to hospital. METHODS: A systematic search was performed across five electronic databases (including MEDLINE, EMBASE and the Cochrane Library) from inception to February 2021. All primary validation studies were eligible if they examined the accuracy of a multivariable RAM (or scoring system) for predicting the risk of developing VTE in hospitalised inpatients. Two or more reviewers independently undertook study selection, data extraction and risk of bias assessments using the PROBAST (Prediction model Risk Of Bias ASsessment Tool) tool. We used narrative synthesis to summarise the findings. RESULTS: Among 6355 records, we included 51 studies, comprising 24 unique validated RAMs. The majority of studies included hospital inpatients who required medical care (21 studies), were undergoing surgery (15 studies) or receiving care for trauma (4 studies). The most widely evaluated RAMs were the Caprini RAM (22 studies), Padua prediction score (16 studies), IMPROVE models (8 studies), the Geneva risk score (4 studies) and the Kucher score (4 studies). C-statistics varied markedly between studies and between models, with no one RAM performing obviously better than other models. Across all models, C-statistics were often weak (<0.7), sometimes good (0.7-0.8) and a few were excellent (>0.8). Similarly, estimates for sensitivity and specificity were highly variable. Sensitivity estimates ranged from 12.0% to 100% and specificity estimates ranged from 7.2% to 100%. CONCLUSION: Available data suggest that RAMs have generally weak predictive accuracy for VTE. There is insufficient evidence and too much heterogeneity to recommend the use of any particular RAM. PROSPERO REGISTRATION NUMBER: Steve Goodacre, Abdullah Pandor, Katie Sworn, Daniel Horner, Mark Clowes. A systematic review of venous thromboembolism RAMs for hospital inpatients. PROSPERO 2020 CRD42020165778. Available from https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=165778https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=165778.

Prehospital continuous positive airway pressure for acute respiratory failure: the ACUTE feasibility RCT.

BACKGROUND: Acute respiratory failure is a life-threatening emergency. Standard prehospital management involves controlled oxygen therapy. Continuous positive airway pressure is a potentially beneficial alternative treatment; however, it is uncertain whether or not this treatment could improve outcomes in NHS ambulance services. OBJECTIVES: To assess the feasibility of a large-scale pragmatic trial and to update an existing economic model to determine cost-effectiveness and the value of further research. DESIGN: (1) An open-label, individual patient randomised controlled external pilot trial. (2) Cost-effectiveness and value-of-information analyses, updating an existing economic model. (3) Ancillary substudies, comprising an acute respiratory failure incidence study, an acute respiratory failure diagnostic agreement study, clinicians perceptions of a continuous positive airway pressure mixed-methods study and an investigation of allocation concealment. SETTING: Four West Midlands Ambulance Service hubs, recruiting between August 2017 and July 2018. PARTICIPANTS: Adults with respiratory distress and peripheral oxygen saturations below the British Thoracic Society's target levels were included. Patients with limited potential to benefit from, or with contraindications to, continuous positive airway pressure were excluded. INTERVENTIONS: Prehospital continuous positive airway pressure (O-Two system, O-Two Medical Technologies Inc., Brampton, ON, Canada) was compared with standard oxygen therapy, titrated to the British Thoracic Society's peripheral oxygen saturation targets. Interventions were provided in identical sealed boxes. MAIN OUTCOME MEASURES: Feasibility objectives estimated the incidence of eligible patients, the proportion recruited and allocated to treatment appropriately, adherence to allocated treatment, and retention and data completeness. The primary clinical end point was 30-day mortality. RESULTS: Seventy-seven patients were enrolled (target 120 patients), including seven patients with a diagnosis for which continuous positive airway pressure could be ineffective or harmful. Continuous positive airway pressure was fully delivered to 74% of participants (target 75%). There were no major protocol violations/non-compliances. Full data were available for all key outcomes (target ≥ 90%). Thirty-day mortality was 27.3%. Of the 21 deceased participants, 14 (68%) either did not have a respiratory condition or had ceiling-of-treatment decision implemented that excluded hospital non-invasive ventilation and critical care. The base-case economic evaluation indicated that standard oxygen therapy was probably cost-effective (incremental cost-effectiveness ratio £5685 per quality-adjusted life-year), but there was considerable uncertainty (population expected value of perfect information of £16.5M). Expected value of partial perfect information analyses indicated that effectiveness of prehospital continuous positive airway pressure was the only important variable. The incidence rate of acute respiratory failure was 17.4 (95% confidence interval 16.3 to 18.5) per 100,000 persons per year. There was moderate agreement between the primary prehospital and final hospital diagnoses (Gwet's AC1 coefficient 0.56, 95% confidence interval 0.43 to 0.69). Lack of hospital awareness of the Ambulance continuous positive airway pressure (CPAP): Use, Treatment Effect and economics (ACUTE) trial, limited time to complete trial training and a desire to provide continuous positive airway pressure treatment were highlighted as key challenges by participating clinicians. LIMITATIONS: During week 10 of recruitment, the continuous positive airway pressure arm equipment boxes developed a 'rattle'. After repackaging and redistribution, no further concerns were noted. A total of 41.4% of ambulance service clinicians not participating in the ACUTE trial indicated a difference between the control and the intervention arm trial boxes (115/278); of these clinician 70.4% correctly identified box contents. CONCLUSIONS: Recruitment rate was below target and feasibility was not demonstrated. The economic evaluation results suggested that a definitive trial could represent value for money. However, limited compliance with continuous positive airway pressure and difficulty in identifying patients who could benefit from continuous positive airway pressure indicate that prehospital continuous positive airway pressure is unlikely to materially reduce mortality. FUTURE WORK: A definitive clinical effectiveness trial of continuous positive airway pressure in the NHS is not recommended. TRIAL REGISTRATION: Current Controlled Trials ISRCTN12048261. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 25, No. 7. See the NIHR Journals Library website for further project information.

Acute respiratory failure is a life-threatening medical emergency. It occurs when heart or lung disease suddenly develops, or deteriorates, and leads to the patient being unable to maintain oxygen levels in their blood. Continuous positive airway pressure is a potentially useful treatment that could be used by paramedics. It involves delivering oxygen under increased pressure through a tight-fitting face mask. However, it is uncertain whether or not it could work effectively in NHS ambulance services, or if it represents value for money. The Ambulance continuous positive airway pressure (CPAP): Use, Treatment Effect and economics (ACUTE) trial investigated whether or not it is possible and worthwhile to undertake a full-scale study comparing continuous positive airway pressure with normal paramedic treatment. Paramedics identified adults with acute respiratory failure when attending 999 emergency calls. Half were randomly assigned to receive continuous positive airway pressure, whereas the other half were treated normally. Patients were then followed up to see what happened to them. Fewer patients than expected were entered into the trial, but paramedics were able to provide treatment with continuous positive airway pressure, and most patients were successfully followed up. It therefore seems possible to do a full-scale trial. A cost-effectiveness model also showed that it is uncertain whether or not continuous positive airway pressure represents value for money for the NHS, so further research might be worthwhile, if continuous positive airway pressure is thought to be effective. However, examination of patients recruited to the trial uncovered important doubts about whether or not continuous positive airway pressure would help them. One-quarter of patients were not able to tolerate the tight continuous positive airway pressure mask. Some of the patients had conditions that are not usually treated by continuous positive airway pressure, or had severe underlying disease that could not be helped by this treatment. Others had collapsed lungs that could have been made worse by continuous positive airway pressure. This means that, although a full-scale trial may be possible, it is difficult to see how continuous positive airway pressure could save enough lives to make a trial worthwhile.

Cost-effectiveness of out-of-hospital continuous positive airway pressure for acute respiratory failure: decision analytic modelling using data from a feasibility trial.

BACKGROUND: Standard prehospital management for Acute respiratory failure (ARF) involves controlled oxygen therapy. Continuous positive airway pressure (CPAP) is a potentially beneficial alternative treatment, however, it is uncertain whether this could improve outcomes and provide value for money. This study aimed to evaluate the cost-effectiveness of prehospital CPAP in ARF. METHODS: A cost-utility economic evaluation was performed using a probabilistic decision tree model synthesising available evidence. The model consisted of a hypothetical cohort of patients in a representative ambulance service with undifferentiated ARF, receiving standard oxygen therapy or prehospital CPAP. Costs and quality adjusted life years (QALYs) were estimated using methods recommended by NICE. RESULTS: In the base case analysis, using CPAP effectiveness estimates form the ACUTE trial, the mean expected costs of standard care and prehospital CPAP were £15,201 and £14,850 respectively and the corresponding mean expected QALYs were 1.190 and 1.128, respectively. The mean ICER estimated as standard oxygen therapy compared to prehospital CPAP was £5685 per QALY which indicated that standard oxygen therapy strategy was likely to be cost-effective at a threshold of £20,000 per QALY (67% probability). The scenario analysis, using effectiveness estimates from an updated meta-analysis, suggested that prehospital CPAP was more effective (mean incremental QALYs of 0.157), but also more expensive (mean incremental costs of £1522), than standard care. The mean ICER, estimated as prehospital CPAP compared to standard care, was £9712 per QALY. At the £20,000 per QALY prehospital CPAP was highly likely to be the most cost-effective strategy (94%). CONCLUSIONS: Cost-effectiveness of prehospital CPAP depends upon the estimate of effectiveness. When based on a small pragmatic feasibility trial, standard oxygen therapy is cost-effective. When based on meta-analysis of heterogeneous trials, CPAP is cost-effective. Value of information analyses support commissioning of a large pragmatic effectiveness trial, providing feasibility and plausibility conditions are met.

Controlled observational study and economic evaluation of the effect of city-centre night-time alcohol intoxication management services on the emergency care system compared with usual care.

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.

Seizure First Aid Training For people with Epilepsy (SAFE) frequently attending emergency departments and their significant others: results of a UK multi-centre randomised controlled pilot trial.

OBJECTIVE: To determine the feasibility and optimal design of a randomised controlled trial (RCT) of Seizure First Aid Training For Epilepsy (SAFE). DESIGN: Pilot RCT with embedded microcosting. SETTING: Three English hospital emergency departments (EDs). PARTICIPANTS: Patients aged ≥16 with established epilepsy reporting ≥2 ED visits in the prior 12 months and their significant others (SOs). INTERVENTIONS: Patients (and their SOs) were randomly allocated (1:1) to SAFE plus treatment-as-usual (TAU) or TAU alone. SAFE is a 4-hour group course. MAIN OUTCOME MEASURES: Two criteria evaluated a definitive RCT's feasibility: (1) ≥20% of eligible patients needed to be consented into the pilot trial; (2) routine data on use of ED over the 12 months postrandomisation needed securing for ≥75%. Other measures included eligibility, ease of obtaining routine data, availability of self-report ED data and comparability, SAFE's effect and intervention cost. RESULTS: Of ED attendees with a suspected seizure, 424 (10.6%) patients were eligible; 53 (12.5%) patients and 38 SOs consented. Fifty-one patients (and 37 SOs) were randomised. Routine data on ED use at 12 months were secured for 94.1% patients. Self-report ED data were available for 66.7% patients. Patients reported more visits compared with routine data. Most (76.9%) patients randomised to SAFE received it and no related serious adverse events occurred. ED use at 12 months was lower in the SAFE+TAU arm compared with TAU alone, but not significantly (rate ratio=0.62, 95% CI 0.33 to 1.17). A definitive trial would need ~674 patient participants and ~39 recruitment sites. Obtaining routine data was challenging, taking ~8.5 months. CONCLUSIONS: In satisfying only one predetermined 'stop/go' criterion, a definitive RCT is not feasible. The low consent rate in the pilot trial raises concerns about a definitive trial's finding's external validity and means it would be expensive to conduct. Research is required into how to optimise recruitment from the target population. TRIAL REGISTRATION NUMBER: ISRCTN13871327.

The acceptability of alcohol intoxication management services to users: A mixed methods study.

INTRODUCTION AND AIMS: Alcohol Intoxication Management Services (AIMS) provide basic care for intoxication and minor injuries, have been increasingly implemented in urban areas characterised by a large number of premises licensed for the sale and on-site consumption of alcohol, with the goal of reducing alcohol's burden on emergency services, including referrals into hospital emergency departments. The acceptability of new health services to users is a key effectiveness outcome. The aim was to describe patient experiences when attending an AIMS and document the acceptability of AIMS to users. DESIGN AND METHODS: A sequential mixed methods study was undertaken involving semi-structured interviews with participants from four AIMS followed by a survey of users recruited from six AIMS. RESULTS: Interviewees (N = 19) were positive about the care they received in AIMS and appreciated the friendly, non-judgemental atmosphere. Survey respondents rated their experience in AIMS positively (on a 0 to 10 Likert scale, mean = 9.34, SD = 1.38, n = 188). Frequently given reasons for attendance included drinking alcohol (57%) and minor injury (42%); 24% said they would have attended the emergency department had the AIMS not been available and 6% said they would have preferred to go to the emergency department; 31% indicated they would have felt unsafe without the AIMS. DISCUSSION AND CONCLUSIONS: AIMS are acceptable to users. AIMS are likely to address previously unmet demand for a safe space within the night-time environment.