Diagnostic accuracy of point-of-care tests for acute respiratory infection: a systematic review of reviews.

Background: Acute respiratory infections are a common reason for consultation with primary and emergency healthcare services. Identifying individuals with a bacterial infection is crucial to ensure appropriate treatment. However, it is also important to avoid overprescription of antibiotics, to prevent unnecessary side effects and antimicrobial resistance. We conducted a systematic review to summarise evidence on the diagnostic accuracy of symptoms, signs and point-of-care tests to diagnose bacterial respiratory tract infection in adults, and to diagnose two common respiratory viruses, influenza and respiratory syncytial virus. Methods: The primary approach was an overview of existing systematic reviews. We conducted literature searches (22 May 2023) to identify systematic reviews of the diagnostic accuracy of point-of-care tests. Where multiple reviews were identified, we selected the most recent and comprehensive review, with the greatest overlap in scope with our review question. Methodological quality was assessed using the Risk of Bias in Systematic Reviews tool. Summary estimates of diagnostic accuracy (sensitivity, specificity or area under the curve) were extracted. Where no systematic review was identified, we searched for primary studies. We extracted sufficient data to construct a 2 × 2 table of diagnostic accuracy, to calculate sensitivity and specificity. Methodological quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies version 2 tool. Where possible, meta-analyses were conducted. We used GRADE to assess the certainty of the evidence from existing reviews and new analyses. Results: We identified 23 reviews which addressed our review question; 6 were selected as the most comprehensive and similar in scope to our review protocol. These systematic reviews considered the following tests for bacterial respiratory infection: individual symptoms and signs; combinations of symptoms and signs (in clinical prediction models); clinical prediction models incorporating C-reactive protein; and biological markers related to infection (including C-reactive protein, procalcitonin and others). We also identified systematic reviews that reported the accuracy of specific tests for influenza and respiratory syncytial virus. No reviews were found that assessed the diagnostic accuracy of white cell count for bacterial respiratory infection, or multiplex tests for influenza and respiratory syncytial virus. We therefore conducted searches for primary studies, and carried out meta-analyses for these index tests. Overall, we found that symptoms and signs have poor diagnostic accuracy for bacterial respiratory infection (sensitivity ranging from 9.6% to 89.1%; specificity ranging from 13.4% to 95%). Accuracy of biomarkers was slightly better, particularly when combinations of biomarkers were used (sensitivity 80-90%, specificity 82-93%). The sensitivity and specificity for influenza or respiratory syncytial virus varied considerably across the different types of tests. Tests involving nucleic acid amplification techniques (either single pathogen or multiplex tests) had the highest diagnostic accuracy for influenza (sensitivity 91-99.8%, specificity 96.8-99.4%). Limitations: Most of the evidence was considered low or very low certainty when assessed with GRADE, due to imprecision in effect estimates, the potential for bias and the inclusion of participants outside the scope of this review (children, or people in hospital). Future work: Currently evidence is insufficient to support routine use of point-of-care tests in primary and emergency care. Further work must establish whether the introduction of point-of-care tests adds value, or simply increases healthcare costs. Funding: This article presents independent research funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme as award number NIHR159948.

Respiratory infections are a common cause of illness. Currently, healthcare professionals use clinical experience to decide whether an infection is caused by a virus or bacteria, and whether antibiotics are needed. However, this is not always easy to establish. We tried to identify the effectiveness of rapid tests (with results in under 45 minutes) at distinguishing between viral and bacterial respiratory infections. We identified and summarised all the existing reviews and studies in this area. We looked at many different tests which aim to distinguish between bacterial and viral causes of respiratory infections. In particular, we assessed: individual symptoms and signs (such as the presence of cough, or a fever) combinations of symptoms and signs (the presence or absence of multiple symptoms) various 'biomarker' tests (blood tests for evidence that the body has used its defence mechanisms) We also looked at specific tests for flu and respiratory syncytial virus, which are common causes of viral infection. The reviews we found showed symptoms and signs were not able to identify bacterial infections in people accurately. The accuracy of biomarker tests was slightly better, particularly when multiple markers were used. The accuracy of rapid tests for flu and respiratory syncytial virus varied; the most accurate tests were those that detect viral genetic material. We also found studies showing that genetic tests that identify many viruses at once (multiplex tests) were very accurate. However, most of the evidence we identified was not robust. There were concerns about the conduct of some of the studies. In some cases there was uncertainty whether a test was really accurate enough to be useful. Therefore there is still doubt about whether any of these tests will be useful additions to current clinical care.

Communicating blood test results in primary care: a mixed methods systematic review.

Background Test result communication is important for patient-centred care, patient safety and primary care workload. Evidence is needed to ensure that test results are communicated safely and efficiently to patients in primary care. Aim To summarize existing evidence for blood test result communication between primary care providers and their patients and carers. Design and setting Mixed-methods systematic review Methods Medline, Embase, PsycINFO (Ovid); CINAHL (ESCOHost); and the Cochrane Library were searched from 2013 to September 2023. Primary studies of any design that provided information on the communication of blood test results by primary care staff to adult patients and carers were eligible for inclusion. Results There were 71 included studies, including 10 experimental studies and no randomized controlled trials. Study quality was mostly poor and risk of bias was high, partly due to a lack of reported information. Patients want more information about their blood test results, particularly in terms of 'what next', and prefer results to be provided quickly. Electronic methods such as online access or text messages were generally well accepted but not by everyone, and not for all results. Clinicians' opinions were mixed as to whether more information and direct release of test results to patients without clinician input was beneficial or could cause problems, such as increased workload. Conclusions We have identified a range of evidence on patient and clinician preferences, barriers and facilitators to test communication, which is particularly important in the current NHS context of a move towards patient online access.

Revised Tool for the Quality Assessment of Diagnostic Accuracy Studies Using AI (QUADAS-AI): Protocol for a Qualitative Study.

BACKGROUND: Quality assessment of diagnostic accuracy studies (QUADAS), and more recently QUADAS-2, were developed to aid the evaluation of methodological quality within primary diagnostic accuracy studies. However, its current form, QUADAS-2 does not address the unique considerations raised by artificial intelligence (AI)-centered diagnostic systems. The rapid progression of the AI diagnostics field mandates suitable quality assessment tools to determine the risk of bias and applicability, and subsequently evaluate translational potential for clinical practice. OBJECTIVE: We aim to develop an AI-specific QUADAS (QUADAS-AI) tool that addresses the specific challenges associated with the appraisal of AI diagnostic accuracy studies. This paper describes the processes and methods that will be used to develop QUADAS-AI. METHODS: The development of QUADAS-AI can be distilled into 3 broad stages. Stage 1-a project organization phase had been undertaken, during which a project team and a steering committee were established. The steering committee consists of a panel of international experts representing diverse stakeholder groups. Following this, the scope of the project was finalized. Stage 2-an item generation process will be completed following (1) a mapping review, (2) a meta-research study, (3) a scoping survey of international experts, and (4) a patient and public involvement and engagement exercise. Candidate items will then be put forward to the international Delphi panel to achieve consensus for inclusion in the revised tool. A modified Delphi consensus methodology involving multiple online rounds and a final consensus meeting will be carried out to refine the tool, following which the initial QUADAS-AI tool will be drafted. A piloting phase will be carried out to identify components that are considered to be either ambiguous or missing. Stage 3-once the steering committee has finalized the QUADAS-AI tool, specific dissemination strategies will be aimed toward academic, policy, regulatory, industry, and public stakeholders, respectively. RESULTS: As of July 2024, the project organization phase, as well as the mapping review and meta-research study, have been completed. We aim to complete the item generation, including the Delphi consensus, and finalize the tool by the end of 2024. Therefore, QUADAS-AI will be able to provide a consensus-derived platform upon which stakeholders may systematically appraise the methodological quality associated with AI diagnostic accuracy studies by the beginning of 2025. CONCLUSIONS: AI-driven systems comprise an increasingly significant proportion of research in clinical diagnostics. Through this process, QUADAS-AI will aid the evaluation of studies in this domain in order to identify bias and applicability concerns. As such, QUADAS-AI may form a key part of clinical, governmental, and regulatory evaluation frameworks for AI diagnostic systems globally. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/58202.

Clinical and cost-effectiveness of clopidogrel resistance genotype testing after ischaemic stroke or transient ischaemic attack: a systematic review and economic model.

Background: Stroke or transient ischaemic attack patients are at increased risk of secondary vascular events. Antiplatelet medications, most commonly clopidogrel, are prescribed to reduce this risk. Factors including CYP2C19 genetic variants can hinder clopidogrel metabolism. Laboratory-based or point-of-care tests can detect these variants, enabling targeted treatment. Objective: To assess the effectiveness of genetic testing to identify clopidogrel resistance in people with ischaemic stroke or transient ischaemic attack. Specific objectives: Do people tested for clopidogrel resistance, and treated accordingly, have a reduced risk of secondary vascular events? Do people with loss-of-function alleles associated with clopidogrel resistance have a reduced risk of secondary vascular events if treated with alternative interventions compared to clopidogrel? Do people with loss-of-function alleles associated with clopidogrel resistance have an increased risk of secondary vascular events when treated with clopidogrel? What is the accuracy of point-of-care tests for detecting variants associated with clopidogrel resistance? What is the technical performance and cost of CYP2C19 genetic tests? Is genetic testing for clopidogrel resistance cost-effective compared with no testing? Design: Systematic review and economic model. Results: Objective 1: Two studies assessed secondary vascular events in patients tested for loss-of-function alleles and treated accordingly. They found a reduced risk, but confidence intervals were wide (hazard ratio 0.50, 95% confidence interval 0.09 to 2.74 and hazard ratio 0.53, 95% confidence interval 0.24 to 1.18). Objective 2: Seven randomised controlled trials compared clopidogrel with alternative treatment in people with genetic variants. Ticagrelor was associated with a lower risk of secondary vascular events than clopidogrel (summary hazard ratio 0.76, 95% confidence interval 0.65 to 0.90; two studies). Objective 3: Twenty-five studies compared outcomes in people with and without genetic variants treated with clopidogrel. People with genetic variants were at an increased risk of secondary vascular events (hazard ratio 1.72, 95% confidence interval 1.43 to 2.08; 18 studies). There was no difference in bleeding risk (hazard ratio 0.98, 95% confidence interval 0.68 to 1.40; five studies). Objective 4: Eleven studies evaluated Genomadix Cube accuracy; no studies evaluated Genedrive. Summary sensitivity and specificity against laboratory reference standards were both 100% (95% confidence interval 94% to 100% and 99% to 100%). Objective 5: Seventeen studies evaluated technical performance of point-of-care tests. Test failure rate ranged from 0.4% to 19% for Genomadix Cube. A survey of 8/10 genomic laboratory hubs revealed variation in preferred technologies for testing, and cost per test ranging from £15 to £250. Most laboratories expected test failure rate to be < 1%. Additional resources could enhance testing capacity and expedite turnaround times. Objective 6: Laboratory and point-of-care CYP2C19 testing strategies were cost-saving and increase quality-adjusted life-years compared with no testing. Both strategies gave similar costs, quality-adjusted life-years and expected net monetary benefit. Conclusions: Our results suggest that CYP2C19 testing followed by tailored treatment is likely to be effective and cost-effective in both populations. Future work: Accuracy and technical performance of Genedrive. Test failure rate of Genomadix Cube in a National Health Service setting. Value of testing additional loss-of-function alleles. Appropriateness of treatment dichotomy based on loss-of-function alleles. Limitations: Lack of data on Genedrive. No randomised 'test-and-treat' studies of dipyramidole plus aspirin. Study registration: This study is registered as PROSPERO CRD42022357661. Funding: This award was funded by the National Institute for Health and Care Research (NIHR) Evidence Synthesis programme (NIHR award ref: NIHR135620) and is published in full in Health Technology Assessment; Vol. 28, No. 57. See the NIHR Funding and Awards website for further award information.

The most common type of stroke occurs when the supply of blood to the brain is cut off. Symptoms of stroke happen suddenly and vary depending on which part of the brain is affected. They usually include problems with movement, speech, vision and the face drooping on one side. A 'transient ischaemic attack' is a milder related condition. There are around 100,000 strokes and 60,000 transient ischaemic attacks every year in the UK. People who have a stroke or transient ischaemic attack are at greater risk of having another stroke. To reduce the chances of this happening, doctors will often prescribe medication. The most common medication used is called 'clopidogrel'. However, clopidogrel does not work for everyone. One reason for this is having specific variations of a gene called the CYP2C19 gene. Around one in three people in the UK have this variation. We wanted to know whether introducing genetic testing to identify variations in the CYP2C19 gene for people who have had a stroke or transient ischaemic attack can help doctors prescribe a treatment that will work for them, reducing the risk of having another stroke. We also wanted to know if doing this test would be a good use of NHS money. Doing a genetic test to identify variations in the CYP2C19 gene, and prescribing an alternative medication for people with these variations, may reduce the chances of having a new stroke. It is likely that a genetic test for variations of the CYP2C19 gene would represent value for money for the NHS.

Accuracy and technical characteristics of CYP2C19 point of care tests: a systematic review.

Aim: To assess the accuracy and technical characteristics of CYP2C19 point of care tests (POCTs).Patients & methods: Systematic review of primary studies, in any population or setting, that evaluated POCTs for detecting CYP2C19 loss of function (LOF) alleles.Results: Eleven studies provided accuracy data (eight Spartan; one Genomadix Cube; one GMEX; one Genedrive). The POCTs had very high sensitivity and specificity for the alleles they tested for. Twenty-two studies reported technical characteristics: POCTs were easy to operate and provided results quickly. Limited data were reported for test failure rate and cost.Conclusion: CYP2C19 POCTs may be a useful alternative to laboratory-based testing to guide antiplatelet therapy. Further data are required on accuracy (GMEX; Genedrive), test failure and cost (all POCT).

[Box: see text].

Introducing the LATITUDES network: a library of assessment tools and training to improve transparency, utility and dissemination in evidence synthesis.

An assessment of the validity of studies is an essential component of most evidence syntheses (systematic reviews) to understand the risk of bias (ROB) and applicability of the evidence. A formal validity assessment requires a structured and comprehensive approach, which can be implemented using an assessment tool, specifically developed for this purpose. Many different tools are available, marking it difficult for researchers to choose the best tool for their evidence synthesis. We have established the LATITUDES Network to assist researchers in identifying the most appropriate tool to use in their evidence synthesis and to support researchers using these tools. The LATITUDES website (www.latitudes-network.org) includes a searchable library of validity assessment tools designed for use in evidence syntheses, bringing tools together in one place and providing researchers with clear information on suitable tools, categorized by study design. The website also provides links to training on the process of validity assessment and a list of tools currently under development. To be included in the LATITUDES library, tools must meet the following criteria: be designed for use in evidence syntheses; assess multidimensional aspects of validity of individual studies or reviews; and be developed for use by the wider research community rather than for a single research group. We highlight 'key' tools, those that are considered to be the most robust and reliable tools based on prespecified criteria agreed in conjunction with our advisory board, an international group of experts in the area of evidence synthesis and ROB tools.

Patient safety in actioning and communicating blood test results in primary care: a UK wide audit using the Primary care Academic CollaboraTive (PACT).

BACKGROUND: Errors associated with failures in filing, actioning and communicating blood test results can lead to delayed and missed diagnoses and patient harm. This study aimed to audit how blood tests in primary care are filed, actioned and communicated in primary care, to identify areas for patient safety improvements. METHODS: UK primary care clinicians were recruited through the Primary Care Academic CollaboraTive (PACT). PACT members audited 50 recent sets of blood tests from their practice and retrospectively extracted data on blood test result coding, actioning and communication. PACT members received a practice report, showing their own results, benchmarked against other participating practices. RESULTS: PACT members from 57 general practices across all four UK nations collected data on 2572 patients who had blood tests in April 2021. In 89.9% (n=2311) they agreed with the initial clinician's actioning of blood tests; 10.1% disagreed, either partially (7.1%) or fully (3.0%).In 44% of patients (n=1132) an action (eg, 'make an appointment') was specified by the filing clinician. This action was carried out in 89.7% (n=1015/1132) of cases; in 6.8% (n=77) the action was not carried out, in 3.5% (n=40) it was unclear. In the 117 cases where the test result had not been actioned 38% (n=45) were felt to be at low risk of harm, 1.7% (n=2) were at high risk of harm, 0.85% (n=1) came to harm.Overall, in 47% (n=1210) of patients there was no evidence in the electronic health records that results had been communicated. Out of 1176 patients with one or more abnormal results there was no evidence of test communication in 30.6% (n=360). There were large variations between practices in rates of actioning and communicating tests. CONCLUSION: This research demonstrates variation in the way blood test results are actioned and communicated, with important patient safety implications.

Exploring factors influencing quality of life variability among individuals with coeliac disease: an online survey.

OBJECTIVE: Patients with coeliac disease (CD) need to follow a strict gluten-free diet to manage symptoms and prevent complications. Restrictions imposed by the diet can be challenging and affect quality of life (QoL). We explored sources of variation in QoL among patients with CD. DESIGN: We conducted an online survey of coeliac patients in the UK, including a CD-specific QoL tool (CD-QOL V.1.0), questions on diet adherence and an optional comment box at the end. The survey was disseminated via social media and went live between January and March 2021. We performed multiple linear regression and free text analysis. RESULTS: We found a median CD-QOL score of 61 (IQR 44-76, range 4-100, n=215) suggesting good QoL (Good >59); however, the individual QoL scores varied significantly. Regression analyses showed that people who found diet adherence difficult and people adhering very strictly had a lower QoL. Free text comments suggested that people who adhered very strictly may do so because they have symptoms with minimal gluten exposure. People who found diet adherence difficult may be people who only recently started the diet and were still adjusting to its impact. Comments also highlighted that individuals with CD often perceive a lack of adequate follow-up care and support after diagnosis. CONCLUSION: Better support and follow-up care is needed for people with CD to help them adjust to a gluten-free diet and minimise the impact on their QoL. Better education and increased awareness are needed among food businesses regarding cross-contamination to reduce anxiety and accidental gluten exposure.

Common challenges and suggestions for risk of bias tool development: a systematic review of methodological studies.

OBJECTIVES: To review the findings of studies that have evaluated the design and/or usability of key risk of bias (RoB) tools for the assessment of RoB in primary studies, as categorized by the Library of Assessment Tools and InsTruments Used to assess Data validity in Evidence Synthesis Network (a searchable library of RoB tools for evidence synthesis): Prediction model Risk Of Bias ASessment Tool (PROBAST) , Risk of Bias-2 (RoB2), Risk Of Bias In Non-randomised Studies of Interventions (ROBINS-I), Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2), Quality Assessment of Diagnostic Accuracy Studies-Comparative (QUADAS-C), Quality Assessment of Prognostic Accuracy Studies (QUAPAS), Risk Of Bias in Non-randomised Studies of Exposures (ROBINS-E), and the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) RoB checklist. STUDY DESIGN AND SETTING: Systematic review of methodological studies. We conducted a forward citation search from the primary report of each tool, to identify primary studies that aimed to evaluate the design and/or usability of the tool. Two reviewers assessed studies for inclusion. We extracted tool features into Microsoft Word and used NVivo for document analysis, comprising a mix of deductive and inductive approaches. We summarized findings within each tool and explored common findings across tools. RESULTS: We identified 13 tool evaluations meeting our inclusion criteria: PROBAST (3), RoB2 (3), ROBINS-I (4), and QUADAS-2 (3). We identified no evaluations for the other tools. Evaluations varied in clinical topic area, methodology, approach to bias assessment, and tool user background. Some had limitations affecting generalizability. We identified common findings across tools for 6/14 themes: (1) challenging items (eg, RoB2/ROBINS-I "deviations from intended interventions" domain), (2) overall RoB judgment (concerns with overall risk calculation in PROBAST/ROBINS-I), (3) tool usability (concerns about complexity), (4) time to complete tool (varying demands on time, eg, depending on number of outcomes assessed), (5) user agreement (varied across tools), and (6) recommendations for future use (eg, piloting) and development (add intermediate domain answer to QUADAS-2/PROBAST; provide clearer guidance for all tools). Of the other eight themes, seven only had findings for the QUADAS-2 tool, limiting comparison across tools, and one ("reorganization of questions") had no findings. CONCLUSION: Evaluations of key RoB tools have posited common challenges and recommendations for tool use and development. These findings may be helpful to people who use or develop RoB tools. Guidance is necessary to support the design and implementation of future RoB tool evaluations.

Cost-Effectiveness of Routine Monitoring of Long-Term Conditions in Primary Care: Informing Decision Modelling with a Systematic Review in Hypertension, Type 2 Diabetes and Chronic Kidney Disease.

BACKGROUND: Long-term conditions (LTCs) are major public health problems with a considerable health-related and economic burden. Modelling is key in assessing costs and benefits of different disease management strategies, including routine monitoring, in the conditions of hypertension, type 2 diabetes mellitus (T2DM) and chronic kidney disease (CKD) in primary care. OBJECTIVE: This review aimed to identify published model-based cost-effectiveness studies of routine laboratory testing strategies in these LTCs to inform a model evaluating the cost effectiveness of testing strategies in the UK. METHODS: We searched the Medline and Embase databases from inception to July 2023; the National Institute for Health and Care Institute (NICE) website was also searched. Studies were included if they were model-based economic evaluations, evaluated testing strategies, assessed regular testing, and considered adults aged >16 years. Studies identified were summarised by testing strategies, model type, structure, inputs, assessment of uncertainty, and conclusions drawn. RESULTS: Five studies were included in the review, i.e. Markov (n = 3) and microsimulation (n = 2) models. Models were applied within T2DM (n = 2), hypertension (n = 1), T2DM/hypertension (n = 1) and CKD (n = 1). Comorbidity between all three LTCs was modelled to varying extents. All studies used a lifetime horizon, except for a 10-year horizon T2DM model, and all used quality-adjusted life-years as the effectiveness outcome, except a TD2M model that used glycaemic control. No studies explicitly provided a rationale for their selected modelling approach. UK models were available for diabetes and CKD, but these compared only a limited set of routine monitoring tests and frequencies. CONCLUSIONS: There were few studies comparing routine testing strategies in the UK, indicating a need to develop a novel model in all three LTCs. Justification for the modelling technique of the identified studies was lacking. Markov and microsimulation models, with and without comorbidities, were used; however, the findings of this review can provide data sources and inform modelling approaches for evaluating the cost effectiveness of testing strategies in all three LTCs.

Methodological review of NMA bias concepts provides groundwork for the development of a list of concepts for potential inclusion in a new risk of bias tool for network meta-analysis (RoB NMA Tool).

INTRODUCTION: Network meta-analyses (NMAs) have gained popularity and grown in number due to their ability to provide estimates of the comparative effectiveness of multiple treatments for the same condition. The aim of this study is to conduct a methodological review to compile a preliminary list of concepts related to bias in NMAs. METHODS AND ANALYSIS: We included papers that present items related to bias, reporting or methodological quality, papers assessing the quality of NMAs, or method papers. We searched MEDLINE, the Cochrane Library and unpublished literature (up to July 2020). We extracted items related to bias in NMAs. An item was excluded if it related to general systematic review quality or bias and was included in currently available tools such as ROBIS or AMSTAR 2. We reworded items, typically structured as questions, into concepts (i.e. general notions). RESULTS: One hundred eighty-one articles were assessed in full text and 58 were included. Of these articles, 12 were tools, checklists or journal standards; 13 were guidance documents for NMAs; 27 were studies related to bias or NMA methods; and 6 were papers assessing the quality of NMAs. These studies yielded 99 items of which the majority related to general systematic review quality and biases and were therefore excluded. The 22 items we included were reworded into concepts specific to bias in NMAs. CONCLUSIONS: A list of 22 concepts was included. This list is not intended to be used to assess biases in NMAs, but to inform the development of items to be included in our tool.

HIGHLIGHTS: • Our research aimed to develop a preliminary list of concepts related to bias with the goal of developing the first tool for assessing the risk of bias in the results and conclusions of a network meta-analysis (NMA).• We followed the methodology proposed by Whiting (2017) and Sanderson (2007) for creating systematically developed lists of quality items, as a first step in the development of a risk of bias tool for network meta-analysis (RoB NMA Tool).• We included items related to biases in NMAs and excluded items that are equally applicable to all systematic reviews as they are covered by other tools (e.g. ROBIS, AMSTAR 2).• Fifty-seven studies were included generating 99 items, which when screened, yielded 22 included items. These items were then reworded into concepts in preparation for a Delphi process for further vetting by external experts.• A limitation of our study is the challenge in retrieving methods studies as methods collections are not regularly updated.

Risk of bias assessments in individual participant data meta-analyses of test accuracy and prediction models: a review shows improvements are needed.

OBJECTIVES: Risk of bias assessments are important in meta-analyses of both aggregate and individual participant data (IPD). There is limited evidence on whether and how risk of bias of included studies or datasets in IPD meta-analyses (IPDMAs) is assessed. We review how risk of bias is currently assessed, reported, and incorporated in IPDMAs of test accuracy and clinical prediction model studies and provide recommendations for improvement. STUDY DESIGN AND SETTING: We searched PubMed (January 2018-May 2020) to identify IPDMAs of test accuracy and prediction models, then elicited whether each IPDMA assessed risk of bias of included studies and, if so, how assessments were reported and subsequently incorporated into the IPDMAs. RESULTS: Forty-nine IPDMAs were included. Nineteen of 27 (70%) test accuracy IPDMAs assessed risk of bias, compared to 5 of 22 (23%) prediction model IPDMAs. Seventeen of 19 (89%) test accuracy IPDMAs used Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2), but no tool was used consistently among prediction model IPDMAs. Of IPDMAs assessing risk of bias, 7 (37%) test accuracy IPDMAs and 1 (20%) prediction model IPDMA provided details on the information sources (e.g., the original manuscript, IPD, primary investigators) used to inform judgments, and 4 (21%) test accuracy IPDMAs and 1 (20%) prediction model IPDMA provided information or whether assessments were done before or after obtaining the IPD of the included studies or datasets. Of all included IPDMAs, only seven test accuracy IPDMAs (26%) and one prediction model IPDMA (5%) incorporated risk of bias assessments into their meta-analyses. For future IPDMA projects, we provide guidance on how to adapt tools such as Prediction model Risk Of Bias ASsessment Tool (for prediction models) and QUADAS-2 (for test accuracy) to assess risk of bias of included primary studies and their IPD. CONCLUSION: Risk of bias assessments and their reporting need to be improved in IPDMAs of test accuracy and, especially, prediction model studies. Using recommended tools, both before and after IPD are obtained, will address this.

Clinical effectiveness of point of care tests for diagnosing urinary tract infection: a systematic review.

BACKGROUND: Point of care tests (POCTs) have the potential to improve the urinary tract infection (UTI) diagnostic pathway, as they can provide a diagnosis quickly in near-patient settings, and some also identify causative pathogens/antimicrobial sensitivity. OBJECTIVES: To assess the clinical impact, accuracy, and technical characteristics of POCT for diagnosing UTI. METHODS OF DATA SYNTHESIS: Narrative summary and bivariate random effects meta-analyses to estimate summary sensitivity and specificity. DATA SOURCES: Five electronic databases, two clinical trial registries, study reports and review reference lists, and websites. STUDY ELIGIBILITY CRITERIA: Randomized controlled trials/non-randomized studies and diagnostic test accuracy studies published since 2000. PARTICIPANTS: People with suspected UTI. TESTS: Rapid tests (results <40 minutes): Astrego PA-100 system, Lodestar DX, Uriscreen, UTRiPLEX. Culture tests (results <24 hours): Flexicult Human, ID Flexicult, Diaslide, Dipstreak, Chromostreak, Uricult, Uricult Trio, Uricult Plus. REFERENCE STANDARD: Any. ASSESSMENT OF RISK OF BIAS: Risk of Bias-2, Quality Assessment of Diagnostic Accuracy Studies-2, Quality Assessment of Diagnostic Accuracy Studies-C. RESULTS: Two randomized controlled trials evaluated Flexicult Human (one against standard care; one against ID Flexicult). No difference was reported in antibiotic use concordant with culture results (OR 0.84 95% CI 0.58-1.20) or appropriate antibiotic prescribing (OR 1.44 95% CI 1.03-1.99). Initial antibiotic prescribing was lower with Flexicult than standard care (OR 0.56 95% CI 0.35-0.88). No difference for other measures of antibiotic use, symptom duration, patient enablement, or resource use. Fifteen studies reported accuracy data. Limited data were available, with most POCT evaluated in single studies or not evaluated at all. Uriscreen (four studies), Uricult Trio (three studies), Flexicult Human (four studies), and ID Flexicult (two studies) had modest sensitivity and specificity. POCTs were easier to use and interpret than standard culture. CONCLUSIONS: There is currently insufficient evidence to support the use of POCTs in UTI diagnosis. Due to the rapid development of POCT, this review should be updated regularly.

Liver function tests in patients with hypertension in primary care: a prospective cohort study.

BACKGROUND: Liver function tests (LFTs) are frequently used to monitor patients with hypertension in UK primary care. Evidence is lacking on whether testing improves outcomes. AIM: To estimate the diagnostic accuracy of LFTs in patients with hypertension and determine downstream consequences of testing. DESIGN & SETTING: Prospective study using the Clinical Practice Research Datalink (CPRD). METHOD: In total, 30 000 patients with hypertension who had LFTs in 2015 were randomly selected from CPRD. The diagnostic accuracy measures for eight LFT analytes and an overall LFT panel were calculated against the reference standard of liver disease. Rates of consultations, blood tests, and referrals within 6 months following testing were measured. RESULTS: The 1-year incidence of liver disease in patients with hypertension was 0.5% (95% confidence interval [CI] = 0.4% to 0.6%). Sensitivity and specificity of an LFT panel were modest: 61.3% (95% CI = 53.1% to 69.0%) and 73.8% (95% CI = 73.1% to 74.3%), respectively. The positive predictive value (PPV) of the eight individual LFT analytes were low ranging from 0.2% to 8.9%. Among patients who did not develop liver disease, mean number of consultations, referrals, and tests were higher in the 6 months following false-positives at 10.5, 0.7 and 29.8, respectively, compared with true-negatives: 8.6, 0.6, and 19.8. CONCLUSION: PPVs of LFTs in primary care were low, with high rates of false-positive results and increased rates of subsequent consultations, referrals, and blood testing. Avoiding LFTs for routine monitoring could potentially reduce patients' anxiety, GP workload, and healthcare costs.

Identifying the Optimum Strategy for Identifying Adults and Children With Celiac Disease: A Cost-Effectiveness and Value of Information Analysis.

OBJECTIVES: Celiac disease (CD) is thought to affect around 1% of people in the United Kingdom, but only approximately 30% are diagnosed. The aim of this work was to assess the cost-effectiveness of strategies for identifying adults and children with CD in terms of who to test and which tests to use. METHODS: A decision tree and Markov model were used to describe testing strategies and model long-term consequences of CD. The analysis compared a selection of pre-test probabilities of CD above which patients should be screened, as well as the use of different serological tests, with or without genetic testing. Value of information analysis was used to prioritize parameters for future research. RESULTS: Using serological testing alone in adults, immunoglobulin A (IgA) tissue transglutaminase (tTG) at a 1% pre-test probability (equivalent to population screening) was most cost-effective. If combining serological testing with genetic testing, human leukocyte antigen combined with IgA tTG at a 5% pre-test probability was most cost-effective. In children, the most cost-effective strategy was a 10% pre-test probability with human leukocyte antigen plus IgA tTG. Value of information analysis highlighted the probability of late diagnosis of CD and the accuracy of serological tests as important parameters. The analysis also suggested prioritizing research in adult women over adult men or children. CONCLUSIONS: For adults, these cost-effectiveness results suggest UK National Screening Committee Criteria for population-based screening for CD should be explored. Substantial uncertainty in the results indicate a high value in conducting further research.

Exploration of reasons for primary care testing (the Why Test study): a UK-wide audit using the Primary care Academic CollaboraTive.

BACKGROUND: Rates of blood testing have increased over the past two decades. Reasons for testing cannot easily be extracted from electronic health record databases. AIM: To explore who requests blood tests and why, and what the outcomes of testing are in UK primary care. DESIGN AND SETTING: A retrospective audit of electronic health records in general practices in England, Wales, Scotland, and Northern Ireland was undertaken. METHOD: Fifty-seven clinicians from the Primary care Academic CollaboraTive (PACT) each reviewed the electronic health records of 50 patients who had blood tests in April 2021. Anonymised data were extracted including patient characteristics, who requested the tests, reasons for testing, test results, and outcomes of testing. RESULTS: Data were collected from 2572 patients across 57 GP practices. The commonest reasons for testing in primary care were investigation of symptoms (43.2%), monitoring of existing disease (30.1%), monitoring of existing medications (10.1%), and follow up of previous abnormalities (6.8%); patient requested testing was rare in this study (1.5%). Abnormal and borderline results were common, with 26.6% of patients having completely normal test results. Around one-quarter of tests were thought to be partially or fully unnecessary when reviewed retrospectively by a clinical colleague. Overall, 6.2% of tests in primary care led to a new diagnosis or confirmation of a diagnosis. CONCLUSION: The utilisation of a national collaborative model (PACT) has enabled a unique exploration of the rationale and outcomes of blood testing in primary care, highlighting areas for future research and optimisation.

Blood test result communication in primary care: mixed-methods systematic review protocol.

BACKGROUND: After testing, ensuring test results are communicated and actioned is important for patient safety, with failure or delay in diagnosis the most common cause of malpractice claims in primary care worldwide. Identifying interventions to improve test communication from the decision to test through to sharing of results has important implications for patient safety, GP workload, and patient engagement. AIM: To assess the factors around communication of blood test results between primary care providers (for example GPs, nurses, reception staff) and their patients and carers. DESIGN & SETTING: A mixed methods systematic review including primary studies involving communication of blood test results in primary care. METHOD: The review will use a segregated convergent synthesis method. Qualitative information will be synthesised using a meta-aggregative approach, and quantitative data will be meta-analysed or synthesised if pooling of studies is appropriate and data are available. If not, data will be presented in tabular and descriptive summary form. CONCLUSION: This review has the potential to provide conclusions about blood test result communication interventions and factors important to stakeholders, including barriers and facilitators to improved communication.

How to Critically Appraise and Interpret Systematic Reviews and Meta-Analyses of Diagnostic Accuracy: A User Guide.

Systematic reviews of diagnostic accuracy studies can provide the best available evidence to inform decisions regarding the use of a diagnostic test. In this guide, the authors provide a practical approach for clinicians to appraise diagnostic accuracy systematic reviews and apply their results to patient care. The first step is to identify an appropriate systematic review with a research question matching the clinical scenario. The user should evaluate the rigor of the review methods to evaluate its credibility (Did the review use clearly defined eligibility criteria, a comprehensive search strategy, structured data collection, risk of bias and applicability appraisal, and appropriate meta-analysis methods?). If the review is credible, the next step is to decide whether the diagnostic performance is adequate for clinical use (Do sensitivity and specificity estimates exceed the threshold that makes them useful in clinical practice? Are these estimates sufficiently precise? Is variability in the estimates of diagnostic accuracy across studies explained?). Diagnostic accuracy systematic reviews that are judged to be credible and provide diagnostic accuracy estimates with sufficient certainty and relevance are the most useful to inform patient care. This review discusses comparative, noncomparative, and emerging approaches to systematic reviews of diagnostic accuracy using a clinical scenario and examples based on recent publications.

Variation in laboratory testing for patients with long-term conditions: a longitudinal cohort study in UK primary care.

BACKGROUND: Use of laboratory testing has increased in the UK over the past few decades, with considerable geographical variation. AIM: To evaluate what laboratory tests are used to monitor people with hypertension, type 2 (T2) diabetes, or chronic kidney disease (CKD) and assess variation in test use in UK primary care. DESIGN & SETTING: Longitudinal cohort study of people registered with UK general practices between June 2013 and May 2018 and previously diagnosed with hypertension, T2 diabetes, or CKD. METHOD: Clinical Practice Research Datalink (CPRD) primary care data linked to ethnic group and deprivation was used to examine testing rates over time, by GP practice, age, sex, ethnic group, and socioeconomic deprivation, with age-sex standardisation. RESULTS: Nearly 1 million patients were included, and more than 27 million tests. The most ordered tests were for renal function (1463 per 1000 person-years), liver function (1063 per 1000 person-years), and full blood count (FBC; 996 per 1000 person-years). There was evidence of undertesting (compared with current guidelines) for HbA1c and albumin:creatinine ratio (ACR) or microalbumin, and potential overtesting of lipids, FBC, liver function, and thyroid function. Some GP practices had up to 27 times higher testing rates than others (HbA1c testing among patients with CKD). CONCLUSION: Testing rates are no longer increasing, but they are not always within the guidelines for monitoring long-term conditions (LTCs). There was considerable variation by GP practice, indicating uncertainty over the most appropriate testing frequencies for different conditions. Standardising the monitoring of LTCs based on the latest evidence would provide greater consistency of access to monitoring tests.