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1.
Diagn Progn Res ; 6(1): 12, 2022 Apr 25.
Article in English | MEDLINE | ID: covidwho-1808409

ABSTRACT

BACKGROUND: In response to the global COVID-19 pandemic, many in vitro diagnostic (IVD) tests for SARS-CoV-2 have been developed. Given the urgent clinical demand, researchers must balance the desire for precise estimates of sensitivity and specificity against the need for rapid implementation. To complement estimates of precision used for sample size calculations, we aimed to estimate the probability that an IVD will fail to perform to expected standards after implementation, following clinical studies with varying sample sizes. METHODS: We assumed that clinical validation study estimates met the 'desirable' performance (sensitivity 97%, specificity 99%) in the target product profile (TPP) published by the Medicines and Healthcare products Regulatory Agency (MHRA). To estimate the real-world impact of imprecision imposed by sample size we used Bayesian posterior calculations along with Monte Carlo simulations with 10,000 independent iterations of 5,000 participants. We varied the prevalence between 1 and 15% and the sample size between 30 and 2,000. For each sample size, we estimated the probability that diagnostic accuracy would fail to meet the TPP criteria after implementation. RESULTS: For a validation study that demonstrates 'desirable' sensitivity within a sample of 30 participants who test positive for COVID-19 using the reference standard, the probability that real-world performance will fail to meet the 'desirable' criteria is 10.7-13.5%, depending on prevalence. Theoretically, demonstrating the 'desirable' performance in 90 positive participants would reduce that probability to below 5%. A marked reduction in the probability of failure to hit 'desirable' specificity occurred between samples of 100 (19.1-21.5%) and 160 (4.3-4.8%) negative participants. There was little further improvement above sample sizes of 160 negative participants. CONCLUSION: Based on imprecision alone, small evaluation studies can lead to the acceptance of diagnostic tests which are likely to fail to meet performance targets when deployed. There is diminished return on uncertainty surrounding an accuracy estimate above a total sample size of 250 (90 positive and 160 negative).

2.
EuropePMC; 2020.
Preprint in English | EuropePMC | ID: ppcovidwho-312350

ABSTRACT

Objectives: The second wave of the coronavirus pandemic is now established, occurring at a time of winter pressure on acute care in the NHS. This is likely to be more challenging then the first wave for the diagnosis of COVID-19 because of the similar symptomology with other respiratory conditions highly prevalent in winter. This study sought to understand the care pathways in place in UK NHS hospitals during the first wave (March-July 2020) for identification of patients with COVID-19 and to learn lessons to inform optimal testing strategies within the COVID-19 National Diagnostic Research and Evaluation Platform (CONDOR). Design: , setting & participants Sixteen hospital-based clinicians from 12 UK NHS Trusts covering 10 different specialties were interviewed following a semi-structured topic guide. Data were coded soon after the interviews and analysed thematically. Results: We developed a diagrammatic, high-level visualisation of the care pathway describing the main clinical decisions associated with the diagnosis and management of patients with suspected COVID-19. COVID-19 testing influenced infection control considerations more so than treatment decisions. Two main features of service provision influenced the patient management significantly: access to rapid laboratory testing and the number of single occupancy rooms. If time to return of result was greater than 24 hours, patients with a presumptive diagnosis would often be cohorted based on clinical suspicion alone. Undetected COVID-19 during this time could therefore lead to an increased risk of viral transmission. Conclusions: During the winter months, priority for provision of rapid testing at admission should be given to hospitals with limited access to laboratory services and single room availability. Access to rapid testing is essential for urgent decisions related to emergency surgery, maternity services and organ transplant. The pathway and prioritization of need will inform the economic modelling, clinical evaluations, and implementation of new clinical tests in UK.

3.
Emergency Medicine Journal : EMJ ; 39(2):85, 2022.
Article in English | ProQuest Central | ID: covidwho-1642889

ABSTRACT

Interestingly, given the relatively recent publication of landmark trials such as AIRWAYS-2 (which identified no benefit with advanced airway management in out of hospital cardiac arrest), Doan et al found that advanced airway management was associated with improved odds of survival to hospital handover. [...]we know that the ‘awareness time interval’ (the time from witnessing cardiac arrest to activating emergency services) is an important prognostic factor for patients with OHCA. [...]linking with the discrete choice experiment asking ‘who should get the scarce intensive care unit bed?’ mentioned above, Walzi et al present the findings of a systematic review of factors influencing decisions to limit treatment in the Emergency Department.

4.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-296965

ABSTRACT

Objectives To compare self-taken and healthcare worker (HCW)-taken throat/nasal swabs to perform rapid diagnostic tests (RDT) for SARS-CoV-2, and how these compare to RT-PCR. We hypothesised that self-taken samples are non-inferior for use with RDTs and in clinical and research settings could have substantial individual and public health benefit. Design A prospective diagnostic accuracy evaluation as part of the ‘Facilitating Accelerated Clinical Evaluation of Novel Diagnostic Tests for COVID -19 (FALCON C-19), workstream C (undifferentiated community testing)’. Setting NHS Test and Trace drive-through community PCR testing site (Liverpool, UK). Participants Eligible participants 18 years or older with symptoms of COVID-19. 250 participants recruited;one withdrew before analysis. Sampling Self-administered throat/nasal swab for the Covios® RDT, a trained HCW taken throat/nasal sample for PCR and HCW comparison throat/nasal swab for RDT. Main outcome measures Sensitivity, specificity, and positive and negative predictive values (PPV, NPV) were calculated;comparisons between self-taken and HCW-taken samples used McNemar’s test. Results Seventy-five participants (75/249, 30.1%) were positive by RT-PCR. RDTs with self-taken swabs had a sensitivity of 90.5% (67/74, 95% CI: 83.9-97.2), compared to 78.4% (58/74, 95% CI: 69.0-87.8) for HCW-taken swabs (absolute difference 12.2%, 95% CI: 4.7-19.6, p=0.003). Specificity for self-taken swabs was 99.4% (173/174, 95% CI: 98.3-100.0), versus 98.9% (172/174, 95% CI: 97.3-100.0) for HCW-taken swabs (absolute difference 0.6%, 95% CI: 0.5-1.7, p=0.317). The PPV of self-taken RDTs (98.5%, 67/68, 95% CI: 95.7-100.0) and HCW-taken RDTs (96.7%, 58/60, 95% CI 92.1-100.0) were not significantly different (p=0.262). However, the NPV of self-taken swab RDTs was significantly higher (96.1%, 173/180, 95% CI: 93.2-98.9) than HCW-taken RDTs (91.5%, 172/188, 95% CI 87.5-95.5, p=0.003). Conclusion Self-taken swabs for COVID-19 testing offer substantial individual benefits in terms of convenience, accuracy, and reduced risk of transmitting infection. Our results demonstrate that self-taken throat/nasal samples can be used by lay individuals as part of rapid testing programmes for symptomatic adults. Trial Registration IRAS ID:28422, clinical trial ID: NCT04408170 Summary What is already known on this topic? Rapid diagnostic tests (RDTs)for SARS-CoV-2 Ag are a cheaper point-of-care alternative to RT-PCR for diagnosing COVID-19 disease. The accuracy of tests can vary dependent on sampling technique, test processing and reading of results. What this study adds? Self-taken throat-nasal swabs for RDTs can be used by symptomatic adults to give reliable results to diagnose SARS-CoV-2. Self-sampling can be implemented with little training and no assistance.

5.
2021.
Preprint in English | Other preprints | ID: ppcovidwho-295483

ABSTRACT

Introduction Successful adoption of POCTs (Point-of-Care tests) for COVID-19 in care homes requires the identification of ideal use cases and a full understanding of contextual and usability factors that affect test results and minimise biosafety risks. This paper presents findings from a scoping-usability and test performance study of a microfluidic immunofluorescence assay for COVID-19 in care homes. Methods A mixed-methods evaluation was conducted in four UK care homes to scope usability and to assess the agreement with qRT-PCR. A dry run with luminescent dye was carried out to explore biosafety issues. Results The agreement analysis was carried out on 227 asymptomatic participants (159 staff and 68 residents) and 14 symptomatic participants (5 staff and 9 residents). Asymptomatic specimens showed 50% (95% CI: 1.3%-98.7%) positive agreement and 96% (95% CI: 92.5%-98.1%) negative agreement with overall prevalence and bias-adjusted Kappa (PABAK) of 0.911 (95% CI: 0.857-0.965). Symptomatic specimens showed 83.3% (95% CI: 35.9%-99.6%) positive agreement and 100% (95% CI: 63.1%-100%) negative agreement with overall prevalence and bias-adjusted Kappa (PABAK) of 0.857 (95% CI: 0.549-1). The dry run showed four main sources of contamination that led to the modification of the standard operating procedures. Simulation after modification showed no further evidence of contamination. Conclusion Careful consideration of biosafety issues and contextual factors associated with care home are mandatory for safe use the POCT. Whilst POCT may have some utility for ruling out COVID-19, further diagnostic accuracy evaluations are needed to promote effective adoption.

6.
Journal of Patient Safety and Risk Management ; : 25160435211054207, 2021.
Article in English | Sage | ID: covidwho-1523271

ABSTRACT

IntroductionSuccessful adoption of POCTs (Point-of-Care tests) for COVID-19 in care homes requires the identification of ideal use cases and a full understanding of the contextual and usability factors that affect test results and minimise biosafety risks. This paper presents a scoping-usability and test performance study of a microfluidic immunofluorescence assay for COVID-19 in care homes.MethodsA mixed-methods evaluation was conducted in four UK care homes to scope usability and to assess the agreement with qRT-PCR. A dry run with luminescent dye was conducted to explore biosafety issues.ResultsThe agreement analysis was conducted on 227 asymptomatic participants (159 staff and 68 residents) and 14 symptomatic participants (5 staff and 9 residents). Asymptomatic specimens showed 50% (95% CI:1.3%?98.7%) positive agreement and 96% (95% CI: 92.5%?98.1%) negative agreement with overall prevalence and bias-adjusted Kappa (PABAK) of 0.911 (95% CI: 0.857?0.965). Symptomatic specimens showed 83.3% (95% CI: 35.9%?99.6%) positive agreement and 100% (95% CI: 63.1%?100%) negative agreement with overall prevalence and bias-adjusted Kappa (PABAK) of 0.857 (95% CI: 0.549?1). The dry run highlighted four main sources of contamination that led to the modification of the standard operating procedures. Simulation post-modification showed no further evidence of contamination.ConclusionCareful consideration of biosafety issues and contextual factors associated with care home are mandatory for safe use the POCT. Whilst POCT may have some utility for ruling out COVID-19, further diagnostic accuracy evaluations are needed to promote effective adoption.

7.
Emerg Med J ; 39(1): 70-76, 2022 Jan.
Article in English | MEDLINE | ID: covidwho-1504636

ABSTRACT

Point-of-care tests for SARS-CoV-2 could enable rapid rule-in and/or rule-out of COVID-19, allowing rapid and accurate patient cohorting and potentially reducing the risk of nosocomial transmission. As COVID-19 begins to circulate with other more common respiratory viruses, there is a need for rapid diagnostics to help clinicians test for multiple potential causative organisms simultaneously.However, the different technologies available have strengths and weaknesses that must be understood to ensure that they are used to the benefit of the patient and healthcare system. Device performance is related to the deployed context, and the diagnostic characteristics may be affected by user experience.This practice review is written by members of the UK's COVID-19 National Diagnostic Research and Evaluation programme. We discuss relative merits and test characteristics of various commercially available technologies. We do not advocate for any given test, and our coverage of commercially supplied tests is not intended to be exhaustive.


Subject(s)
COVID-19 , Humans , Point-of-Care Testing , SARS-CoV-2
10.
Emergency Medicine Journal : EMJ ; 38(7):485, 2021.
Article in English | ProQuest Central | ID: covidwho-1280441

ABSTRACT

[...]Daskal et al have examined the significance of flail chest. Ultrasound-Guided reduction of distal radial fractures With the rise of the use of ultrasound in emergency medicine, an interesting use case is to guide the reduction of distal radial fractures. Smits et al asked emergency physicians to record what they believed to be the causative agent when they were treating patients with apparent drug overdoses.

11.
BMJ Open ; 11(6): e044457, 2021 06 16.
Article in English | MEDLINE | ID: covidwho-1276957

ABSTRACT

INTRODUCTION: In conjunction with a beta-lactam, aminoglycosides are the first-choice antibiotic for empirical treatment of sepsis in the neonatal period. The m.1555A>G variant predisposes to ototoxicity after aminoglycoside administration and has a prevalence of 1 in 500. Current genetic testing can take over 24 hours, an unacceptable delay in the acute setting. This prospective-observational trial will implement a rapid point of care test (POCT), facilitating tailored antibiotic prescribing to avoid hearing loss. METHODS AND ANALYSIS: The genedrive POCT can detect the m.1555A>G variant in 26 min from buccal swab. This system will be integrated into the clinical pathways at two large UK neonatal centres over a minimum 6-month period. The primary outcome is the number of neonates successfully tested for the variant out of all babies prescribed antibiotics. As a secondary outcome, clinical timings will be compared with data collected prior to implementation, measuring the impact on routine practice. ETHICS AND DISSEMINATION: Approval for the trial was granted by the Research Ethics Committee (REC) and Human Research Authority in August 2019. Results will be published in full on completion of the study. TRIAL REGISTRATION NUMBER: ISRCTN13704894. PROTOCOL VERSION: V 1.3.


Subject(s)
Deafness , Pharmacogenetics , Hearing , Humans , Infant, Newborn , Observational Studies as Topic , Point-of-Care Testing , Prospective Studies
12.
BMJ Simul Technol Enhanc Learn ; 7(6): 524-527, 2021.
Article in English | MEDLINE | ID: covidwho-1276970

ABSTRACT

Purpose of the study: SARS-CoV-2 has caused healthcare systems globally to reorganise. A pandemic paradox emerged; while clinicians were desperate for information on a new disease, they had less time to find and evaluate the vast volume of publications at times of significant strain on healthcare systems.A multidisciplinary team undertook a weekly literature search capturing all COVID-19 publications. We also monitored free open access medical education (FOAMed) sources for emerging themes. Title and abstract screening pooled the most relevant papers for emergency medicine. Three summary types were created, a 'Top 5 Flash Update', a journal club and a rapid response to emerging FOAMed themes. From these summaries, three modes of dissemination were used: short written summaries, blogs and podcasts. These were amplified through social media. Study design: A retrospective review was conducted assessing the impact of this knowledge dissemination strategy for the period of March to September 2020. Results: In total, 64 687 papers were identified and screened. Of the papers included in the 'Top 5', 28.3% were on epidemiology, 23.6% treatment, 16.7% diagnostics, 12% prognosis, 8.7% pathophysiology with the remaining 10.7% consisting of PPE, public health, well-being and 'other'. We published 37 blogs, 17 podcasts and 18 Top 5 Flash Updates. The blogs were read 138 343 times, the Top 5 Flash Updates 68 610 times and the podcasts had 72 501 listens. Conclusion: A combination of traditional academic and novel social media approaches can address the pandemic paradox clinicians are facing.

13.
BMC Health Serv Res ; 21(1): 532, 2021 May 31.
Article in English | MEDLINE | ID: covidwho-1249555

ABSTRACT

OBJECTIVES: The second wave of the coronavirus pandemic is now established, occurring at a time of winter pressure on acute care in the NHS. This is likely to be more challenging then the first wave for the diagnosis of COVID-19 because of the similar symptomology with other respiratory conditions highly prevalent in winter. This study sought to understand the care pathways in place in UK NHS hospitals during the first wave (March-July 2020) for identification of patients with COVID-19 and to learn lessons to inform optimal testing strategies within the COVID-19 National Diagnostic Research and Evaluation Platform (CONDOR). DESIGN, SETTING & PARTICIPANTS: Sixteen hospital-based clinicians from 12 UK NHS Trusts covering 10 different specialties were interviewed following a semi-structured topic guide. Data were coded soon after the interviews and analysed thematically. RESULTS: We developed a diagrammatic, high-level visualisation of the care pathway describing the main clinical decisions associated with the diagnosis and management of patients with suspected COVID-19. COVID-19 testing influenced infection control considerations more so than treatment decisions. Two main features of service provision influenced the patient management significantly: access to rapid laboratory testing and the number of single occupancy rooms. If time to return of result was greater than 24 h, patients with a presumptive diagnosis would often be cohorted based on clinical suspicion alone. Undetected COVID-19 during this time could therefore lead to an increased risk of viral transmission. CONCLUSIONS: During the winter months, priority for provision of rapid testing at admission should be given to hospitals with limited access to laboratory services and single room availability. Access to rapid testing is essential for urgent decisions related to emergency surgery, maternity services and organ transplant. The pathway and prioritization of need will inform the economic modelling, clinical evaluations, and implementation of new clinical tests in UK.


Subject(s)
COVID-19 Testing , COVID-19 , Female , Hospitals , Humans , Pregnancy , SARS-CoV-2 , United Kingdom/epidemiology
14.
Age Ageing ; 50(5): 1442-1444, 2021 09 11.
Article in English | MEDLINE | ID: covidwho-1226520

ABSTRACT

COVID-19 has devastated care homes. Point-of-care tests (POCTs), mainly using lateral flow devices (LFDs), have been deployed hurriedly without much consideration of their usability or impact on care workflow. Even after the pandemic, POCTs, particularly multiplex tests, may be an important control against spread of SARS-CoV-2 and other respiratory infections in care homes by enabling identification of cases. They should not, however, replace other infection control measures such as barrier methods and quarantine. Adherence to LFDs as implemented among care home staff is suboptimal. Other tests-such as point-of-care polymerase chain reaction and automated antigen tests-would also need to be accommodated into care home workflows to improve adherence. The up-front costs of POCTs are straightforward but additional costs, including staffing preparation and reporting processes and the impacts of false positive and negative tests on absence rates and infection days, are more complex and as yet unquantified. A detailed appraisal is needed as the future of testing in care homes is considered.


Subject(s)
COVID-19 , Humans , Pandemics , Point-of-Care Testing , Policy , SARS-CoV-2
15.
Emerg. Med. J. ; 5(37): 249-20200501.
Article in English | WHO COVID, ELSEVIER | ID: covidwho-1186357
16.
Emerg Med J ; 37(9): 572-575, 2020 Sep.
Article in English | MEDLINE | ID: covidwho-1024251

ABSTRACT

The COVID-19 pandemic has led to a surge of information being presented to clinicians regarding this novel and deadly disease. There is a clear urgency to collate, review, appraise and act on this information if we are to do the best for clinicians and patients. However, the speed of the pandemic is a threat to traditional models of knowledge translation and practice change. In this concepts paper, we argue that clinicians need to be agile in their thinking and practice in order to find the right time to change. Adoption of new methods should be based on clinical judgement, the weight of evidence and the balance of probabilities that any new technique, test or treatment might work. The pandemic requires all of us to reach a new level of evidence-based medicine characterised by scepticism, thoughtfulness, responsiveness and clinically agility in practice.


Subject(s)
Coronavirus Infections , Critical Pathways , Evidence-Based Medicine , Pandemics , Pneumonia, Viral , Betacoronavirus , COVID-19 , Coronavirus Infections/epidemiology , Coronavirus Infections/prevention & control , Coronavirus Infections/therapy , Critical Pathways/organization & administration , Critical Pathways/trends , Evidence-Based Medicine/education , Evidence-Based Medicine/methods , Evidence-Based Medicine/organization & administration , Humans , Knowledge Management , Organizational Innovation , Pandemics/prevention & control , Pneumonia, Viral/epidemiology , Pneumonia, Viral/prevention & control , Pneumonia, Viral/therapy , Quality Improvement , SARS-CoV-2 , Surge Capacity , /trends
17.
Emergency Medicine Journal : EMJ ; 37(12):830-831, 2020.
Article in English | ProQuest Central | ID: covidwho-939886

ABSTRACT

131 Figure 1Results/ConclusionsThe data shows similar levels of between year activity from July 2018 through to February 2019. It then shows a rapid and profound increase in activity from March 2019, coinciding with the rapid spread of the pandemic in Europe and an early blog/podcast with colleagues from Northern Italy. Since then activity has fallen but still remains roughly 1.5 times higher than in previous years. Combined visits to the blog and podcast peaked at 162,019 engagements, representing a near 6.9 fold increase in podcast engagement and a 2.7 increase in blog activity during May 2019.The COVID-19 pandemic resulted in a rapid and sustained engagement with the St Emlyn’s platform. The reasons for this are unclear from the data presented here, but we believe reflect the superior agility of modern educational tools such as blogs and podcasts to share and disseminate information as compared to traditional academic publishing methods.

19.
Ultrasound ; 2020.
Article in English | WHO COVID, ELSEVIER | ID: covidwho-704789

ABSTRACT

Background: During the novel coronavirus disease 2019 (COVID-19) pandemic, rapid diagnostics have been frequently sought to quickly evaluate a patient’s condition. Lung ultrasound can provide an early glimpse into the disease process and its severity. The addition of focused echocardiography can be particularly helpful in the haemodynamically compromised patient to detect myocardial involvement and alternative diagnoses. Case: We discuss here a 53-year-old patient who presented to the Emergency Department with hypoxia and hypotension. Bedside focused ultrasound revealed signs of COVID-19 pneumonia with evidence of right ventricular strain, initially thought to be due to massive pulmonary embolism. A computed tomography scan confirmed the findings on ultrasonography, but surprisingly did not demonstrate a pulmonary embolism. Conclusion: Point-of-care ultrasound in COVID-19 aided the diagnosis of affected organs and helped categorise the type of shock in this patient; however, right ventricular dysfunction should be interpreted with caution and may not be due to a pulmonary embolism, as in this case.

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