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1.
Diabet Med ; 39(1): e14730, 2022 01.
Artículo en Inglés | MEDLINE | ID: mdl-34676911

RESUMEN

AIMS: Type 1 diabetes is characterised by the destruction of pancreatic ß-cells. Significant levels of ß-cells remain at diagnosis. Preserving these cells improves glucose control and protects from long-term complications. We undertook a systematic review and meta-analyses of all randomised controlled trials (RCTs) of interventions to preserve ß-cell function in people newly diagnosed with type 1 diabetes. This paper reports the results of interventions for improving glucose control to assess whether they preserve ß-cell function. METHODS: Searches for RCTs in MEDLINE, Embase, Cochrane CENTRAL, ClinicalTrials.gov and WHO International Clinical Trials Registry. Eligible studies included newly diagnosed patients with type 1 diabetes, any intervention to improve glucose control and at least 1 month of follow-up. Data were extracted using a pre-defined data-extraction sheet with 10% of extractions checked by a second reviewer. RESULTS: Twenty-eight studies with 1662 participants were grouped by intervention into six subgroups (alternative insulins, subcutaneous and intravenous insulin delivery, intensive therapy, glucose sensing, adjuncts). Only three studies demonstrated an improvement in glucose control as well as ß-cell function. These interventions included intensive insulin therapy and use of an alternative insulin. CONCLUSIONS: This is the largest comprehensive review of RCTs in this area. It demonstrates a lack of robust evidence that interventions to improve glucose control preserve ß-cell function in new onset type 1 diabetes, although analysis was hampered by low-quality evidence and inconsistent reporting of studies. Development of guidelines to support the design of trials in this field is a priority.


Asunto(s)
Glucemia/metabolismo , Diabetes Mellitus Tipo 1/tratamiento farmacológico , Control Glucémico/normas , Células Secretoras de Insulina/metabolismo , Insulina/administración & dosificación , Diabetes Mellitus Tipo 1/sangre , Ayuno , Humanos , Hipoglucemiantes/administración & dosificación , Células Secretoras de Insulina/efectos de los fármacos
2.
Ocul Immunol Inflamm ; 30(1): 137-148, 2022 Jan 02.
Artículo en Inglés | MEDLINE | ID: mdl-33021418

RESUMEN

PURPOSE: This systematic review aims to identify instrument-based tests for quantifying vitreous inflammation in uveitis, report the test reliability and the level of correlation with clinician grading. METHODS: Studies describing instrument-based tests for detecting vitreous inflammation were identified by searching bibliographic databases and trials registers. Test reliability measures and level of correlation with clinician vitreous haze grading are extracted. RESULTS: Twelve studies describing ultrasound, optical coherence tomography (OCT), and retinal photography for detecting vitreous inflammation were included: Ultrasound was used for detection of disease features, whereas OCT and retinal photography provided quantifiable measurements. Correlation with clinician grading for OCT was 0.53-0.60 (three studies) and for retinal photography was 0.51 (1 study). Both instruments showed high inter- and intra-observer reliability (>0.70 intraclass correlation and Cohen's kappa), where reported in four studies. CONCLUSION: Retinal photography and OCT are able to detect and measure vitreous inflammation. Both techniques are reliable, automatable, and warrant further evaluation.


Asunto(s)
Uveítis , Humanos , Inflamación/diagnóstico , Reproducibilidad de los Resultados , Tomografía de Coherencia Óptica/métodos , Uveítis/diagnóstico
3.
Cochrane Database Syst Rev ; 3: CD013705, 2021 03 24.
Artículo en Inglés | MEDLINE | ID: mdl-33760236

RESUMEN

BACKGROUND: Accurate rapid diagnostic tests for SARS-CoV-2 infection could contribute to clinical and public health strategies to manage the COVID-19 pandemic. Point-of-care antigen and molecular tests to detect current infection could increase access to testing and early confirmation of cases, and expediate clinical and public health management decisions that may reduce transmission. OBJECTIVES: To assess the diagnostic accuracy of point-of-care antigen and molecular-based tests for diagnosis of SARS-CoV-2 infection. We consider accuracy separately in symptomatic and asymptomatic population groups. SEARCH METHODS: Electronic searches of the Cochrane COVID-19 Study Register and the COVID-19 Living Evidence Database from the University of Bern (which includes daily updates from PubMed and Embase and preprints from medRxiv and bioRxiv) were undertaken on 30 Sept 2020. We checked repositories of COVID-19 publications and included independent evaluations from national reference laboratories, the Foundation for Innovative New Diagnostics and the Diagnostics Global Health website to 16 Nov 2020. We did not apply language restrictions. SELECTION CRITERIA: We included studies of people with either suspected SARS-CoV-2 infection, known SARS-CoV-2 infection or known absence of infection, or those who were being screened for infection. We included test accuracy studies of any design that evaluated commercially produced, rapid antigen or molecular tests suitable for a point-of-care setting (minimal equipment, sample preparation, and biosafety requirements, with results within two hours of sample collection). We included all reference standards that define the presence or absence of SARS-CoV-2 (including reverse transcription polymerase chain reaction (RT-PCR) tests and established diagnostic criteria). DATA COLLECTION AND ANALYSIS: Studies were screened independently in duplicate with disagreements resolved by discussion with a third author. Study characteristics were extracted by one author and checked by a second; extraction of study results and assessments of risk of bias and applicability (made using the QUADAS-2 tool) were undertaken independently in duplicate. We present sensitivity and specificity with 95% confidence intervals (CIs) for each test and pooled data using the bivariate model separately for antigen and molecular-based tests. We tabulated results by test manufacturer and compliance with manufacturer instructions for use and according to symptom status. MAIN RESULTS: Seventy-eight study cohorts were included (described in 64 study reports, including 20 pre-prints), reporting results for 24,087 samples (7,415 with confirmed SARS-CoV-2). Studies were mainly from Europe (n = 39) or North America (n = 20), and evaluated 16 antigen and five molecular assays. We considered risk of bias to be high in 29 (50%) studies because of participant selection; in 66 (85%) because of weaknesses in the reference standard for absence of infection; and in 29 (45%) for participant flow and timing. Studies of antigen tests were of a higher methodological quality compared to studies of molecular tests, particularly regarding the risk of bias for participant selection and the index test. Characteristics of participants in 35 (45%) studies differed from those in whom the test was intended to be used and the delivery of the index test in 39 (50%) studies differed from the way in which the test was intended to be used. Nearly all studies (97%) defined the presence or absence of SARS-CoV-2 based on a single RT-PCR result, and none included participants meeting case definitions for probable COVID-19. Antigen tests Forty-eight studies reported 58 evaluations of antigen tests. Estimates of sensitivity varied considerably between studies. There were differences between symptomatic (72.0%, 95% CI 63.7% to 79.0%; 37 evaluations; 15530 samples, 4410 cases) and asymptomatic participants (58.1%, 95% CI 40.2% to 74.1%; 12 evaluations; 1581 samples, 295 cases). Average sensitivity was higher in the first week after symptom onset (78.3%, 95% CI 71.1% to 84.1%; 26 evaluations; 5769 samples, 2320 cases) than in the second week of symptoms (51.0%, 95% CI 40.8% to 61.0%; 22 evaluations; 935 samples, 692 cases). Sensitivity was high in those with cycle threshold (Ct) values on PCR ≤25 (94.5%, 95% CI 91.0% to 96.7%; 36 evaluations; 2613 cases) compared to those with Ct values >25 (40.7%, 95% CI 31.8% to 50.3%; 36 evaluations; 2632 cases). Sensitivity varied between brands. Using data from instructions for use (IFU) compliant evaluations in symptomatic participants, summary sensitivities ranged from 34.1% (95% CI 29.7% to 38.8%; Coris Bioconcept) to 88.1% (95% CI 84.2% to 91.1%; SD Biosensor STANDARD Q). Average specificities were high in symptomatic and asymptomatic participants, and for most brands (overall summary specificity 99.6%, 95% CI 99.0% to 99.8%). At 5% prevalence using data for the most sensitive assays in symptomatic people (SD Biosensor STANDARD Q and Abbott Panbio), positive predictive values (PPVs) of 84% to 90% mean that between 1 in 10 and 1 in 6 positive results will be a false positive, and between 1 in 4 and 1 in 8 cases will be missed. At 0.5% prevalence applying the same tests in asymptomatic people would result in PPVs of 11% to 28% meaning that between 7 in 10 and 9 in 10 positive results will be false positives, and between 1 in 2 and 1 in 3 cases will be missed. No studies assessed the accuracy of repeated lateral flow testing or self-testing. Rapid molecular assays Thirty studies reported 33 evaluations of five different rapid molecular tests. Sensitivities varied according to test brand. Most of the data relate to the ID NOW and Xpert Xpress assays. Using data from evaluations following the manufacturer's instructions for use, the average sensitivity of ID NOW was 73.0% (95% CI 66.8% to 78.4%) and average specificity 99.7% (95% CI 98.7% to 99.9%; 4 evaluations; 812 samples, 222 cases). For Xpert Xpress, the average sensitivity was 100% (95% CI 88.1% to 100%) and average specificity 97.2% (95% CI 89.4% to 99.3%; 2 evaluations; 100 samples, 29 cases). Insufficient data were available to investigate the effect of symptom status or time after symptom onset. AUTHORS' CONCLUSIONS: Antigen tests vary in sensitivity. In people with signs and symptoms of COVID-19, sensitivities are highest in the first week of illness when viral loads are higher. The assays shown to meet appropriate criteria, such as WHO's priority target product profiles for COVID-19 diagnostics ('acceptable' sensitivity ≥ 80% and specificity ≥ 97%), can be considered as a replacement for laboratory-based RT-PCR when immediate decisions about patient care must be made, or where RT-PCR cannot be delivered in a timely manner. Positive predictive values suggest that confirmatory testing of those with positive results may be considered in low prevalence settings. Due to the variable sensitivity of antigen tests, people who test negative may still be infected. Evidence for testing in asymptomatic cohorts was limited. Test accuracy studies cannot adequately assess the ability of antigen tests to differentiate those who are infectious and require isolation from those who pose no risk, as there is no reference standard for infectiousness. A small number of molecular tests showed high accuracy and may be suitable alternatives to RT-PCR. However, further evaluations of the tests in settings as they are intended to be used are required to fully establish performance in practice. Several important studies in asymptomatic individuals have been reported since the close of our search and will be incorporated at the next update of this review. Comparative studies of antigen tests in their intended use settings and according to test operator (including self-testing) are required.


Asunto(s)
Antígenos Virales/análisis , Prueba Serológica para COVID-19/métodos , COVID-19/diagnóstico , Técnicas de Diagnóstico Molecular/métodos , Sistemas de Atención de Punto , SARS-CoV-2/inmunología , Adulto , Infecciones Asintomáticas , Sesgo , Prueba de Ácido Nucleico para COVID-19 , Prueba Serológica para COVID-19/normas , Niño , Estudios de Cohortes , Reacciones Falso Negativas , Reacciones Falso Positivas , Humanos , Técnicas de Diagnóstico Molecular/normas , Valor Predictivo de las Pruebas , Estándares de Referencia , Sensibilidad y Especificidad
4.
Ocul Immunol Inflamm ; 29(5): 982-990, 2021 Jul 04.
Artículo en Inglés | MEDLINE | ID: mdl-32255392

RESUMEN

Purpose: Anterior chamber (AC) flare is a key sign for anterior uveitis. New instrument-based techniques for measuring AC flare can offer automation and objectivity. This review aims to identify objective instrument-based measures for AC flare.Methods: In this systematic review, we identified studies reporting correlation between instrument-based tests versus clinician AC flare grading, and/or aqueous protein concentration, as well as test reliability.Results: Four index tests were identified in 11 studies: laser-flare photometry (LFP), optical coherence tomography, ocular flare analysis meter (OFAM) and the double-pass technique. The correlation between LFP and clinician grading was 0.40-0.93 and 0.87-0.94 for LFP and protein concentration. The double-pass technique showed no correlation with clinician grading and insufficient information was available for OFAM.Conclusion: LFP shows moderate to strong correlation with clinician grading and aqueous protein concentration. LFP could be a superior reference test compared to clinician AC flare grading for validating new index tests.


Asunto(s)
Cámara Anterior/patología , Humor Acuoso/metabolismo , Técnicas de Diagnóstico Oftalmológico , Proteínas del Ojo/metabolismo , Uveítis Anterior/diagnóstico , Cámara Anterior/metabolismo , Humanos , Fotometría/métodos , Tomografía de Coherencia Óptica/métodos , Uveítis Anterior/metabolismo
5.
J Clin Epidemiol ; 127: 167-174, 2020 11.
Artículo en Inglés | MEDLINE | ID: mdl-32798714

RESUMEN

OBJECTIVES: Comparative diagnostic test accuracy systematic reviews (DTA reviews) assess the accuracy of two or more tests and compare their diagnostic performance. We investigated how comparative DTA reviews assessed the risk of bias (RoB) in primary studies that compared multiple index tests. STUDY DESIGN AND SETTING: This is an overview of comparative DTA reviews indexed in MEDLINE from January 1st to December 31st, 2017. Two assessors independently identified DTA reviews including at least two index tests and containing at least one statement in which the accuracy of the index tests was compared. Two assessors independently extracted data on the methods used to assess RoB in studies that directly compared the accuracy of multiple index tests. RESULTS: We included 238 comparative DTA reviews. Only two reviews (0.8%, 95% confidence interval 0.1 to 3.0%) conducted RoB assessment of test comparisons undertaken in primary studies; neither used an RoB tool specifically designed to assess bias in test comparisons. CONCLUSION: Assessment of RoB in test comparisons undertaken in primary studies was uncommon in comparative DTA reviews, possibly due to lack of existing guidance on and awareness of potential sources of bias. Based on our findings, guidance on how to assess and incorporate RoB in comparative DTA reviews is needed.


Asunto(s)
Sesgo , Pruebas Diagnósticas de Rutina/normas , Revisiones Sistemáticas como Asunto , Intervalos de Confianza , Exactitud de los Datos , Humanos
6.
Cochrane Database Syst Rev ; 8: CD013705, 2020 08 26.
Artículo en Inglés | MEDLINE | ID: mdl-32845525

RESUMEN

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the resulting COVID-19 pandemic present important diagnostic challenges. Several diagnostic strategies are available to identify or rule out current infection, identify people in need of care escalation, or to test for past infection and immune response. Point-of-care antigen and molecular tests to detect current SARS-CoV-2 infection have the potential to allow earlier detection and isolation of confirmed cases compared to laboratory-based diagnostic methods, with the aim of reducing household and community transmission. OBJECTIVES: To assess the diagnostic accuracy of point-of-care antigen and molecular-based tests to determine if a person presenting in the community or in primary or secondary care has current SARS-CoV-2 infection. SEARCH METHODS: On 25 May 2020 we undertook electronic searches in the Cochrane COVID-19 Study Register and the COVID-19 Living Evidence Database from the University of Bern, which is updated daily with published articles from PubMed and Embase and with preprints from medRxiv and bioRxiv. In addition, we checked repositories of COVID-19 publications. We did not apply any language restrictions. SELECTION CRITERIA: We included studies of people with suspected current SARS-CoV-2 infection, known to have, or not to have SARS-CoV-2 infection, or where tests were used to screen for infection. We included test accuracy studies of any design that evaluated antigen or molecular tests suitable for a point-of-care setting (minimal equipment, sample preparation, and biosafety requirements, with results available within two hours of sample collection). We included all reference standards to define the presence or absence of SARS-CoV-2 (including reverse transcription polymerase chain reaction (RT-PCR) tests and established clinical diagnostic criteria). DATA COLLECTION AND ANALYSIS: Two review authors independently screened studies and resolved any disagreements by discussion with a third review author. One review author independently extracted study characteristics, which were checked by a second review author. Two review authors independently extracted 2x2 contingency table data and assessed risk of bias and applicability of the studies using the QUADAS-2 tool. We present sensitivity and specificity, with 95% confidence intervals (CIs), for each test using paired forest plots. We pooled data using the bivariate hierarchical model separately for antigen and molecular-based tests, with simplifications when few studies were available. We tabulated available data by test manufacturer. MAIN RESULTS: We included 22 publications reporting on a total of 18 study cohorts with 3198 unique samples, of which 1775 had confirmed SARS-CoV-2 infection. Ten studies took place in North America, two in South America, four in Europe, one in China and one was conducted internationally. We identified data for eight commercial tests (four antigen and four molecular) and one in-house antigen test. Five of the studies included were only available as preprints. We did not find any studies at low risk of bias for all quality domains and had concerns about applicability of results across all studies. We judged patient selection to be at high risk of bias in 50% of the studies because of deliberate over-sampling of samples with confirmed COVID-19 infection and unclear in seven out of 18 studies because of poor reporting. Sixteen (89%) studies used only a single, negative RT-PCR to confirm the absence of COVID-19 infection, risking missing infection. There was a lack of information on blinding of index test (n = 11), and around participant exclusions from analyses (n = 10). We did not observe differences in methodological quality between antigen and molecular test evaluations. Antigen tests Sensitivity varied considerably across studies (from 0% to 94%): the average sensitivity was 56.2% (95% CI 29.5 to 79.8%) and average specificity was 99.5% (95% CI 98.1% to 99.9%; based on 8 evaluations in 5 studies on 943 samples). Data for individual antigen tests were limited with no more than two studies for any test. Rapid molecular assays Sensitivity showed less variation compared to antigen tests (from 68% to 100%), average sensitivity was 95.2% (95% CI 86.7% to 98.3%) and specificity 98.9% (95% CI 97.3% to 99.5%) based on 13 evaluations in 11 studies of on 2255 samples. Predicted values based on a hypothetical cohort of 1000 people with suspected COVID-19 infection (with a prevalence of 10%) result in 105 positive test results including 10 false positives (positive predictive value 90%), and 895 negative results including 5 false negatives (negative predictive value 99%). Individual tests We calculated pooled results of individual tests for ID NOW (Abbott Laboratories) (5 evaluations) and Xpert Xpress (Cepheid Inc) (6 evaluations). Summary sensitivity for the Xpert Xpress assay (99.4%, 95% CI 98.0% to 99.8%) was 22.6 (95% CI 18.8 to 26.3) percentage points higher than that of ID NOW (76.8%, (95% CI 72.9% to 80.3%), whilst the specificity of Xpert Xpress (96.8%, 95% CI 90.6% to 99.0%) was marginally lower than ID NOW (99.6%, 95% CI 98.4% to 99.9%; a difference of -2.8% (95% CI -6.4 to 0.8)) AUTHORS' CONCLUSIONS: This review identifies early-stage evaluations of point-of-care tests for detecting SARS-CoV-2 infection, largely based on remnant laboratory samples. The findings currently have limited applicability, as we are uncertain whether tests will perform in the same way in clinical practice, and according to symptoms of COVID-19, duration of symptoms, or in asymptomatic people. Rapid tests have the potential to be used to inform triage of RT-PCR use, allowing earlier detection of those testing positive, but the evidence currently is not strong enough to determine how useful they are in clinical practice. Prospective and comparative evaluations of rapid tests for COVID-19 infection in clinically relevant settings are urgently needed. Studies should recruit consecutive series of eligible participants, including both those presenting for testing due to symptoms and asymptomatic people who may have come into contact with confirmed cases. Studies should clearly describe symptomatic status and document time from symptom onset or time since exposure. Point-of-care tests must be conducted on samples according to manufacturer instructions for use and be conducted at the point of care. Any future research study report should conform to the Standards for Reporting of Diagnostic Accuracy (STARD) guideline.


Asunto(s)
Betacoronavirus , Técnicas de Laboratorio Clínico/métodos , Infecciones por Coronavirus/diagnóstico , Neumonía Viral/diagnóstico , Sistemas de Atención de Punto , Antígenos Virales/análisis , COVID-19 , Prueba de COVID-19 , Infecciones por Coronavirus/epidemiología , Reacciones Falso Negativas , Reacciones Falso Positivas , Humanos , Pandemias , Neumonía Viral/epidemiología , SARS-CoV-2 , Sensibilidad y Especificidad
7.
Cochrane Database Syst Rev ; 6: CD013652, 2020 06 25.
Artículo en Inglés | MEDLINE | ID: mdl-32584464

RESUMEN

BACKGROUND: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus and resulting COVID-19 pandemic present important diagnostic challenges. Several diagnostic strategies are available to identify current infection, rule out infection, identify people in need of care escalation, or to test for past infection and immune response. Serology tests to detect the presence of antibodies to SARS-CoV-2 aim to identify previous SARS-CoV-2 infection, and may help to confirm the presence of current infection. OBJECTIVES: To assess the diagnostic accuracy of antibody tests to determine if a person presenting in the community or in primary or secondary care has SARS-CoV-2 infection, or has previously had SARS-CoV-2 infection, and the accuracy of antibody tests for use in seroprevalence surveys. SEARCH METHODS: We undertook electronic searches in the Cochrane COVID-19 Study Register and the COVID-19 Living Evidence Database from the University of Bern, which is updated daily with published articles from PubMed and Embase and with preprints from medRxiv and bioRxiv. In addition, we checked repositories of COVID-19 publications. We did not apply any language restrictions. We conducted searches for this review iteration up to 27 April 2020. SELECTION CRITERIA: We included test accuracy studies of any design that evaluated antibody tests (including enzyme-linked immunosorbent assays, chemiluminescence immunoassays, and lateral flow assays) in people suspected of current or previous SARS-CoV-2 infection, or where tests were used to screen for infection. We also included studies of people either known to have, or not to have SARS-CoV-2 infection. We included all reference standards to define the presence or absence of SARS-CoV-2 (including reverse transcription polymerase chain reaction tests (RT-PCR) and clinical diagnostic criteria). DATA COLLECTION AND ANALYSIS: We assessed possible bias and applicability of the studies using the QUADAS-2 tool. We extracted 2x2 contingency table data and present sensitivity and specificity for each antibody (or combination of antibodies) using paired forest plots. We pooled data using random-effects logistic regression where appropriate, stratifying by time since post-symptom onset. We tabulated available data by test manufacturer. We have presented uncertainty in estimates of sensitivity and specificity using 95% confidence intervals (CIs). MAIN RESULTS: We included 57 publications reporting on a total of 54 study cohorts with 15,976 samples, of which 8526 were from cases of SARS-CoV-2 infection. Studies were conducted in Asia (n = 38), Europe (n = 15), and the USA and China (n = 1). We identified data from 25 commercial tests and numerous in-house assays, a small fraction of the 279 antibody assays listed by the Foundation for Innovative Diagnostics. More than half (n = 28) of the studies included were only available as preprints. We had concerns about risk of bias and applicability. Common issues were use of multi-group designs (n = 29), inclusion of only COVID-19 cases (n = 19), lack of blinding of the index test (n = 49) and reference standard (n = 29), differential verification (n = 22), and the lack of clarity about participant numbers, characteristics and study exclusions (n = 47). Most studies (n = 44) only included people hospitalised due to suspected or confirmed COVID-19 infection. There were no studies exclusively in asymptomatic participants. Two-thirds of the studies (n = 33) defined COVID-19 cases based on RT-PCR results alone, ignoring the potential for false-negative RT-PCR results. We observed evidence of selective publication of study findings through omission of the identity of tests (n = 5). We observed substantial heterogeneity in sensitivities of IgA, IgM and IgG antibodies, or combinations thereof, for results aggregated across different time periods post-symptom onset (range 0% to 100% for all target antibodies). We thus based the main results of the review on the 38 studies that stratified results by time since symptom onset. The numbers of individuals contributing data within each study each week are small and are usually not based on tracking the same groups of patients over time. Pooled results for IgG, IgM, IgA, total antibodies and IgG/IgM all showed low sensitivity during the first week since onset of symptoms (all less than 30.1%), rising in the second week and reaching their highest values in the third week. The combination of IgG/IgM had a sensitivity of 30.1% (95% CI 21.4 to 40.7) for 1 to 7 days, 72.2% (95% CI 63.5 to 79.5) for 8 to 14 days, 91.4% (95% CI 87.0 to 94.4) for 15 to 21 days. Estimates of accuracy beyond three weeks are based on smaller sample sizes and fewer studies. For 21 to 35 days, pooled sensitivities for IgG/IgM were 96.0% (95% CI 90.6 to 98.3). There are insufficient studies to estimate sensitivity of tests beyond 35 days post-symptom onset. Summary specificities (provided in 35 studies) exceeded 98% for all target antibodies with confidence intervals no more than 2 percentage points wide. False-positive results were more common where COVID-19 had been suspected and ruled out, but numbers were small and the difference was within the range expected by chance. Assuming a prevalence of 50%, a value considered possible in healthcare workers who have suffered respiratory symptoms, we would anticipate that 43 (28 to 65) would be missed and 7 (3 to 14) would be falsely positive in 1000 people undergoing IgG/IgM testing at days 15 to 21 post-symptom onset. At a prevalence of 20%, a likely value in surveys in high-risk settings, 17 (11 to 26) would be missed per 1000 people tested and 10 (5 to 22) would be falsely positive. At a lower prevalence of 5%, a likely value in national surveys, 4 (3 to 7) would be missed per 1000 tested, and 12 (6 to 27) would be falsely positive. Analyses showed small differences in sensitivity between assay type, but methodological concerns and sparse data prevent comparisons between test brands. AUTHORS' CONCLUSIONS: The sensitivity of antibody tests is too low in the first week since symptom onset to have a primary role for the diagnosis of COVID-19, but they may still have a role complementing other testing in individuals presenting later, when RT-PCR tests are negative, or are not done. Antibody tests are likely to have a useful role for detecting previous SARS-CoV-2 infection if used 15 or more days after the onset of symptoms. However, the duration of antibody rises is currently unknown, and we found very little data beyond 35 days post-symptom onset. We are therefore uncertain about the utility of these tests for seroprevalence surveys for public health management purposes. Concerns about high risk of bias and applicability make it likely that the accuracy of tests when used in clinical care will be lower than reported in the included studies. Sensitivity has mainly been evaluated in hospitalised patients, so it is unclear whether the tests are able to detect lower antibody levels likely seen with milder and asymptomatic COVID-19 disease. The design, execution and reporting of studies of the accuracy of COVID-19 tests requires considerable improvement. Studies must report data on sensitivity disaggregated by time since onset of symptoms. COVID-19-positive cases who are RT-PCR-negative should be included as well as those confirmed RT-PCR, in accordance with the World Health Organization (WHO) and China National Health Commission of the People's Republic of China (CDC) case definitions. We were only able to obtain data from a small proportion of available tests, and action is needed to ensure that all results of test evaluations are available in the public domain to prevent selective reporting. This is a fast-moving field and we plan ongoing updates of this living systematic review.


Asunto(s)
Anticuerpos Antivirales/sangre , Betacoronavirus/inmunología , Infecciones por Coronavirus/diagnóstico , Infecciones por Coronavirus/inmunología , Neumonía Viral/diagnóstico , Neumonía Viral/inmunología , Especificidad de Anticuerpos , COVID-19 , Infecciones por Coronavirus/epidemiología , Reacciones Falso Negativas , Reacciones Falso Positivas , Humanos , Inmunoglobulina A/sangre , Inmunoglobulina G/sangre , Inmunoglobulina M/sangre , Pandemias , Neumonía Viral/epidemiología , Estándares de Referencia , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/normas , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/estadística & datos numéricos , SARS-CoV-2 , Sesgo de Selección , Sensibilidad y Especificidad , Pruebas Serológicas/métodos , Pruebas Serológicas/normas
8.
Ocul Immunol Inflamm ; 28(6): 898-907, 2020 Aug 17.
Artículo en Inglés | MEDLINE | ID: mdl-31418609

RESUMEN

PURPOSE: New instrument-based techniques for anterior chamber (AC) cell counting can offer automation and objectivity above clinician assessment. This review aims to identify such instruments and its correlation with clinician estimates. METHODS: Using standard systematic review methodology, we identified and tabulated the outcomes of studies reporting reliability and correlation between instrument-based measurements and clinician AC cell grading. RESULTS: From 3470 studies, 6 reported correlation between an instrument-based AC cell count to clinician grading. The two instruments were optical coherence tomography (OCT) and laser flare-cell photometry (LFCP). Correlation between clinician grading and LFCP was 0.66-0.87 and 0.06-0.97 between clinician grading and OCT. OCT volume scans demonstrated correlation between 0.75 and 0.78. Line scans in the middle AC demonstrated higher correlation (0.73-0.97) than in the inferior AC (0.06-0.56). CONCLUSION: AC cell count by OCT and LFP can achieve high levels of correlation with clinician grading, whilst offering additional advantages of speed, automation, and objectivity.


Asunto(s)
Cámara Anterior/patología , Fotometría/instrumentación , Tomografía de Coherencia Óptica/instrumentación , Uveítis/diagnóstico , Recuento de Células , Humanos
9.
Syst Rev ; 8(1): 287, 2019 11 26.
Artículo en Inglés | MEDLINE | ID: mdl-31771628

RESUMEN

BACKGROUND: Inflammation in anterior uveitis is characterised by breakdown of the blood-ocular barrier, which allows leakage of blood constituents of higher molecular weight into the aqueous humour. In routine clinical care, increase in aqueous protein levels can be observed at the slit lamp as 'flare' and the severity can be graded using various clinical grading systems, of which the Standardization of Uveitis Nomenclature (SUN) grading system is most commonly used. Alternative instrument-based technologies are available, which can detect aqueous protein levels in an objective and quantifiable way. This review will identify instruments capable of measuring anterior chamber inflammation in this way, their level of reliability, and how well the measurements correlate with clinical grading and/or actual aqueous protein concentration. METHODS: Standard systematic review methodology will be used to identify, select and extract data from studies that report the use of any instrument-based technology in the assessment of aqueous protein levels. Searches will be conducted through bibliographic databases (MEDLINE, EMBASE and Cochrane Library), clinical trial registries and the grey literature. No restrictions will be placed on language or year of publication. The outcomes of interest are the level of correlation between identified instrument-based test measurements, clinical grading and/or actual aqueous protein concentration, as well as the reliability of each index test identified. Study quality assessment will be based on QUADAS2. Correlation and reliability outcomes will be pooled and meta-analysed if appropriate. DISCUSSION: The assessment of inflammation in anterior chamber protein levels currently relies on crude and subjective clinical examination. The findings of this review will identify non-invasive technologies which show good correlation with actual protein concentration, which could be used in routine clinical practice for objective monitoring of AC inflammation. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42017084167. Study screening stage has just been completed.


Asunto(s)
Humor Acuoso/metabolismo , Técnicas de Diagnóstico Oftalmológico , Proteínas/metabolismo , Uveítis Anterior/metabolismo , Humanos , Reproducibilidad de los Resultados , Proyectos de Investigación , Índice de Severidad de la Enfermedad , Revisiones Sistemáticas como Asunto , Uveítis Anterior/diagnóstico por imagen
10.
BMJ Open ; 9(9): e029311, 2019 09 06.
Artículo en Inglés | MEDLINE | ID: mdl-31494608

RESUMEN

OBJECTIVE: This systematic review aimed to evaluate the ability of risk tools to predict the future episodes of suicide/self-harm in adolescents. DESIGN: Systematic review. DATA SOURCES: MEDLINE, EMBASE, CINAHL and PsycINFO were searched from inception to 3 March 2018. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: Cohort studies, case-control studies and randomised controlled trials of adolescents aged 10-25 who had undergone risk assessment in a clinical setting following an episode of self-harm were included. DATA EXTRACTION AND SYNTHESIS: Two independent reviewers extracted data and assessed risk of bias. Data were grouped by tool and narrative synthesis undertaken, with studies appraised using a checklist combining the QUIPS (Quality In Prognosis Studies) and QUADAS-2 (Quality Assessment of Diagnostic Accuracy Studies) tools. RESULTS: Of the 17 137 articles initially identified, 11 studies evaluating 10 separate tools were included. The studies varied in setting, population and outcome measure. The majority of the studies were rated as having an unclear risk of bias, and meta-analysis was not possible due to high variability between studies.The ability of the tools to correctly identify those adolescents going on to make a self-harm/suicide attempt ranged from 27% (95% CI 10.7% to 50.2%) to 95.8% (95% CI 78.9% to 99.9%). A variety of metrics were provided for 1-10 points increases in various tools, for example, odds and HRs. CONCLUSIONS: This systematic review is the first to explore the use of assessment tools in adolescents. The predictive ability of these tools varies greatly. No single tool is suitable for predicting a higher risk of suicide or self-harm in adolescent populations. PROSPERO REGISTRATION NUMBER: CRD42017058686.


Asunto(s)
Medición de Riesgo/métodos , Conducta Autodestructiva , Suicidio , Adolescente , Conducta del Adolescente , Humanos , Valor Predictivo de las Pruebas , Psicología del Adolescente
11.
Syst Rev ; 8(1): 87, 2019 Apr 04.
Artículo en Inglés | MEDLINE | ID: mdl-30947743

RESUMEN

BACKGROUND: Self-harm and suicide have been identified as serious public health problems in children, adolescents, and young people across the world. Suicide is a major cause of mortality in this population and is commonly preceded by self-harm. Both suicide and self-harm are difficult to predict, and several risk scales and tools are in use for this purpose. Currently, there is only a small amount of evidence available regarding their predictive ability in clinical practice, and no consensus as to which is the most suitable for particular populations or settings. The aim of this review is to evaluate the ability of risk scales to predict future episodes of suicide or self-harm in adolescents and young adults presenting to clinical services with attempted suicide or an episode of self-harm. METHODS: A comprehensive search of electronic databases (MEDLINE, EMBASE, CINAHL, and PsycINFO) from inception will be conducted to identify studies that look at the ability of risk scales to predict suicide or future episodes of self-harm in adolescents and young adults presenting to clinical services with attempted suicide or an episode of self-harm. Two authors will independently carry out key methodological steps such as study screening and selection and data extraction. Quality assessment will be carried out using a checklist developed from the QUIPS and QUADAS-2 tools. Data will be grouped by tool and a narrative synthesis undertaken. For each tool, meta-analysis will be undertaken for ability to predict suicide or repeat self-harm where clinical and methodological homogeneity exists. DISCUSSION: This systematic review will be the first to explore the use of assessment scales/tools in an adolescent population and will help to inform current practice regarding scales/tools with higher predictive ability. There is currently no evidence specifically for this population and a clear need with a high prevalence of self-harm and suicide in adolescents. Additionally, this review will help guide future research into suicide and self-harm prediction and prevention. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42017058686.


Asunto(s)
Escalas de Valoración Psiquiátrica , Medición de Riesgo , Conducta Autodestructiva/diagnóstico , Prevención del Suicidio , Adolescente , Factores de Edad , Humanos , Recurrencia , Medición de Riesgo/métodos , Conducta Autodestructiva/prevención & control , Suicidio/psicología , Adulto Joven , Revisiones Sistemáticas como Asunto
12.
BMJ Open Gastroenterol ; 6(1): e000255, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30899537

RESUMEN

BACKGROUND AND AIMS: Little is known about the relationship between inflammatory bowel disease (IBD) and body image. The aim of this systematic review was to summarise the evidence on body image dissatisfaction in patients with IBD across four areas: (1) body image tools, (2) prevalence, (3) factors associated with body image dissatisfaction in IBD and (4) association between IBD and quality of life. METHODS: Two reviewers screened, selected, quality assessed and extracted data from studies in duplicate. EMBASE, MEDLINE, PsycINFO and Cochrane CENTRAL were searched to April 2018. Study design-specific critical appraisal tools were used to assess risk of bias. Narrative analysis was undertaken due to heterogeneity. RESULTS: Fifty-seven studies using a body image tool were included; 31 for prevalence and 16 and 8 for associated factors and association with quality of life, respectively. Studies reported mainly mean or median scores. Evidence suggested female gender, age, fatigue, disease activity and steroid use were associated with increased body image dissatisfaction, which was also associated with decreased quality of life. CONCLUSION: This is the first systematic review on body image in patients with IBD. The evidence suggests that body image dissatisfaction can negatively impact patients, and certain factors are associated with increased body image dissatisfaction. Greater body image dissatisfaction was also associated with poorer quality of life. However, the methodological and reporting quality of studies was in some cases poor with considerable heterogeneity. Future IBD research should incorporate measurement of body image dissatisfaction using validated tools.

13.
Syst Rev ; 7(1): 184, 2018 Nov 13.
Artículo en Inglés | MEDLINE | ID: mdl-30424797

RESUMEN

BACKGROUND: Inflammatory bowel disease (IBD) is a debilitating chronic disease characterised by inflammation and ulceration of the gastrointestinal tract. It is associated with a range of debilitating symptoms and reduced quality of life. People living with IBD may also be at risk of body image dissatisfaction (BID). BID is a distorted and negative view of the physical self, which in turn can adversely affect mental health and quality of life. To date, there have been no systematic reviews of the evidence on BID in IBD patients. Therefore, the aim of this systematic review is to clarify the evidence base on BID in *IBD patients including (i) the tools used to measure BID, (ii) the prevalence and severity of BID, (iii) the risk factors associated with BID and (iv) the relationship between BID and quality of life. METHODS: Bibliographic databases (EMBASE, MEDLINE, PsycINFO, Cochrane CENTRAL) will be searched using a sensitive search strategy aiming to identify any quantitative study reporting on body image in the context of IBD. This will be supplemented by searches of ongoing trials registers and checking of reference lists. Studies will be assessed for eligibility using predetermined selection criteria for each question. Data will be extracted using a predefined data extraction form, and risk of bias (quality) of included studies will be assessed based on checklists appropriate to the study designs identified. Key methodological steps will be undertaken in duplicate to minimise bias and error. Synthesis will be undertaken separately for the different systematic review sub-questions. Given the anticipated heterogeneity of evidence on each question, it is likely that synthesis will be mostly narrative. DISCUSSION: To the best of our knowledge, this will be the first systematic review to collate the existing evidence on BID in IBD patients. Understanding the impact of BID, its relationship with quality of life, and which patients may be at greater risk, may ultimately lead to the development of interventions to prevent or treat BID and to better patient care. Any gaps in the identified evidence will help to inform the research agenda in this area. SYSTEMATIC REVIEW REGISTRATION: PROSPERO: (CRD42018060999).


Asunto(s)
Imagen Corporal/psicología , Enfermedades Inflamatorias del Intestino/psicología , Calidad de Vida/psicología , Enfermedad Crónica , Emociones , Humanos , Revisiones Sistemáticas como Asunto
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