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1.
Nat Commun ; 12(1): 886, 2021 02 09.
Artigo em Inglês | MEDLINE | ID: mdl-33563987

RESUMO

Large studies such as UK Biobank are increasingly used for GWAS and Mendelian randomization (MR) studies. However, selection into and dropout from studies may bias genetic and phenotypic associations. We examine genetic factors affecting participation in four optional components in up to 451,306 UK Biobank participants. We used GWAS to identify genetic variants associated with participation, MR to estimate effects of phenotypes on participation, and genetic correlations to compare participation bias across different studies. 32 variants were associated with participation in one of the optional components (P < 6 × 10-9), including loci with links to intelligence and Alzheimer's disease. Genetic correlations demonstrated that participation bias was common across studies. MR showed that longer educational duration, older menarche and taller stature increased participation, whilst higher levels of adiposity, dyslipidaemia, neuroticism, Alzheimer's and schizophrenia reduced participation. Our effect estimates can be used for sensitivity analysis to account for selective participation biases in genetic or non-genetic analyses.


Assuntos
Bancos de Espécimes Biológicos/estatística & dados numéricos , Participação da Comunidade/estatística & dados numéricos , Predisposição Genética para Doença/epidemiologia , Feminino , Loci Gênicos , Variação Genética , Estudo de Associação Genômica Ampla , Humanos , Masculino , Análise da Randomização Mendeliana , Pessoa de Meia-Idade , Fatores de Risco , Viés de Seleção , Reino Unido/epidemiologia
3.
Cochrane Database Syst Rev ; 2: CD013665, 2021 02 23.
Artigo em Inglês | MEDLINE | ID: mdl-33620086

RESUMO

BACKGROUND: The clinical implications of SARS-CoV-2 infection are highly variable. Some people with SARS-CoV-2 infection remain asymptomatic, whilst the infection can cause mild to moderate COVID-19 and COVID-19 pneumonia in others. This can lead to some people requiring intensive care support and, in some cases, to death, especially in older adults. Symptoms such as fever, cough, or loss of smell or taste, and signs such as oxygen saturation are the first and most readily available diagnostic information. Such information could be used to either rule out COVID-19, or select patients for further testing. This is an update of this review, the first version of which published in July 2020. OBJECTIVES: To assess the diagnostic accuracy of signs and symptoms to determine if a person presenting in primary care or to hospital outpatient settings, such as the emergency department or dedicated COVID-19 clinics, has COVID-19. SEARCH METHODS: For this review iteration we undertook electronic searches up to 15 July 2020 in the Cochrane COVID-19 Study Register and the University of Bern living search database. In addition, we checked repositories of COVID-19 publications. We did not apply any language restrictions. SELECTION CRITERIA: Studies were eligible if they included patients with clinically suspected COVID-19, or if they recruited known cases with COVID-19 and controls without COVID-19. Studies were eligible when they recruited patients presenting to primary care or hospital outpatient settings. Studies in hospitalised patients were only included if symptoms and signs were recorded on admission or at presentation. Studies including patients who contracted SARS-CoV-2 infection while admitted to hospital were not eligible. The minimum eligible sample size of studies was 10 participants. All signs and symptoms were eligible for this review, including individual signs and symptoms or combinations. We accepted a range of reference standards. DATA COLLECTION AND ANALYSIS: Pairs of review authors independently selected all studies, at both title and abstract stage and full-text stage. They resolved any disagreements by discussion with a third review author. Two review authors independently extracted data and resolved disagreements by discussion with a third review author. Two review authors independently assessed risk of bias using the Quality Assessment tool for Diagnostic Accuracy Studies (QUADAS-2) checklist. We presented sensitivity and specificity in paired forest plots, in receiver operating characteristic space and in dumbbell plots. We estimated summary parameters using a bivariate random-effects meta-analysis whenever five or more primary studies were available, and whenever heterogeneity across studies was deemed acceptable. MAIN RESULTS: We identified 44 studies including 26,884 participants in total. Prevalence of COVID-19 varied from 3% to 71% with a median of 21%. There were three studies from primary care settings (1824 participants), nine studies from outpatient testing centres (10,717 participants), 12 studies performed in hospital outpatient wards (5061 participants), seven studies in hospitalised patients (1048 participants), 10 studies in the emergency department (3173 participants), and three studies in which the setting was not specified (5061 participants). The studies did not clearly distinguish mild from severe COVID-19, so we present the results for all disease severities together. Fifteen studies had a high risk of bias for selection of participants because inclusion in the studies depended on the applicable testing and referral protocols, which included many of the signs and symptoms under study in this review. This may have especially influenced the sensitivity of those features used in referral protocols, such as fever and cough. Five studies only included participants with pneumonia on imaging, suggesting that this is a highly selected population. In an additional 12 studies, we were unable to assess the risk for selection bias. This makes it very difficult to judge the validity of the diagnostic accuracy of the signs and symptoms from these included studies. The applicability of the results of this review update improved in comparison with the original review. A greater proportion of studies included participants who presented to outpatient settings, which is where the majority of clinical assessments for COVID-19 take place. However, still none of the studies presented any data on children separately, and only one focused specifically on older adults. We found data on 84 signs and symptoms. Results were highly variable across studies. Most had very low sensitivity and high specificity. Only cough (25 studies) and fever (7 studies) had a pooled sensitivity of at least 50% but specificities were moderate to low. Cough had a sensitivity of 67.4% (95% confidence interval (CI) 59.8% to 74.1%) and specificity of 35.0% (95% CI 28.7% to 41.9%). Fever had a sensitivity of 53.8% (95% CI 35.0% to 71.7%) and a specificity of 67.4% (95% CI 53.3% to 78.9%). The pooled positive likelihood ratio of cough was only 1.04 (95% CI 0.97 to 1.11) and that of fever 1.65 (95% CI 1.41 to 1.93). Anosmia alone (11 studies), ageusia alone (6 studies), and anosmia or ageusia (6 studies) had sensitivities below 50% but specificities over 90%. Anosmia had a pooled sensitivity of 28.0% (95% CI 17.7% to 41.3%) and a specificity of 93.4% (95% CI 88.3% to 96.4%). Ageusia had a pooled sensitivity of 24.8% (95% CI 12.4% to 43.5%) and a specificity of 91.4% (95% CI 81.3% to 96.3%). Anosmia or ageusia had a pooled sensitivity of 41.0% (95% CI 27.0% to 56.6%) and a specificity of 90.5% (95% CI 81.2% to 95.4%). The pooled positive likelihood ratios of anosmia alone and anosmia or ageusia were 4.25 (95% CI 3.17 to 5.71) and 4.31 (95% CI 3.00 to 6.18) respectively, which is just below our arbitrary definition of a 'red flag', that is, a positive likelihood ratio of at least 5. The pooled positive likelihood ratio of ageusia alone was only 2.88 (95% CI 2.02 to 4.09). Only two studies assessed combinations of different signs and symptoms, mostly combining fever and cough with other symptoms. These combinations had a specificity above 80%, but at the cost of very low sensitivity (< 30%). AUTHORS' CONCLUSIONS: The majority of individual signs and symptoms included in this review appear to have very poor diagnostic accuracy, although this should be interpreted in the context of selection bias and heterogeneity between studies. Based on currently available data, neither absence nor presence of signs or symptoms are accurate enough to rule in or rule out COVID-19. The presence of anosmia or ageusia may be useful as a red flag for COVID-19. The presence of fever or cough, given their high sensitivities, may also be useful to identify people for further testing. Prospective studies in an unselected population presenting to primary care or hospital outpatient settings, examining combinations of signs and symptoms to evaluate the syndromic presentation of COVID-19, are still urgently needed. Results from such studies could inform subsequent management decisions.


Assuntos
Assistência Ambulatorial , Atenção Primária à Saúde , Avaliação de Sintomas , Ageusia/diagnóstico , Ageusia/etiologia , /etiologia , Artralgia/diagnóstico , Artralgia/etiologia , Viés , /epidemiologia , Tosse/diagnóstico , Tosse/etiologia , Diarreia/diagnóstico , Diarreia/etiologia , Dispneia/diagnóstico , Dispneia/etiologia , Fadiga/diagnóstico , Fadiga/etiologia , Febre/diagnóstico , Febre/etiologia , Cefaleia/diagnóstico , Cefaleia/etiologia , Humanos , Mialgia/diagnóstico , Mialgia/etiologia , Ambulatório Hospitalar/estatística & dados numéricos , Pandemias , Exame Físico , Viés de Seleção , Avaliação de Sintomas/classificação , Avaliação de Sintomas/estatística & dados numéricos
4.
BMC Med Res Methodol ; 21(1): 30, 2021 02 10.
Artigo em Inglês | MEDLINE | ID: mdl-33568100

RESUMO

BACKGROUND: In infectious disease transmission dynamics, the high heterogeneity in individual infectiousness indicates that few index cases generate large numbers of secondary cases, which is commonly known as superspreading events. The heterogeneity in transmission can be measured by describing the distribution of the number of secondary cases as a negative binomial (NB) distribution with dispersion parameter, k. However, such inference framework usually neglects the under-ascertainment of sporadic cases, which are those without known epidemiological link and considered as independent clusters of size one, and this may potentially bias the estimates. METHODS: In this study, we adopt a zero-truncated likelihood-based framework to estimate k. We evaluate the estimation performance by using stochastic simulations, and compare it with the baseline non-truncated version. We exemplify the analytical framework with three contact tracing datasets of COVID-19. RESULTS: We demonstrate that the estimation bias exists when the under-ascertainment of index cases with 0 secondary case occurs, and the zero-truncated inference overcomes this problem and yields a less biased estimator of k. We find that the k of COVID-19 is inferred at 0.32 (95%CI: 0.15, 0.64), which appears slightly smaller than many previous estimates. We provide the simulation codes applying the inference framework in this study. CONCLUSIONS: The zero-truncated framework is recommended for less biased transmission heterogeneity estimates. These findings highlight the importance of individual-specific case management strategies to mitigate COVID-19 pandemic by lowering the transmission risks of potential super-spreaders with priority.


Assuntos
Distribuição Binomial , /transmissão , Simulação por Computador , Transmissão de Doença Infecciosa/estatística & dados numéricos , Humanos , Infectologia/estatística & dados numéricos , Funções Verossimilhança , Pandemias , Vigilância da População , Viés de Seleção
5.
Cochrane Database Syst Rev ; 1: CD013855, 2021 01 27.
Artigo em Inglês | MEDLINE | ID: mdl-33502759

RESUMO

BACKGROUND: Caries is one of the most prevalent and preventable conditions worldwide. If identified early enough then non-invasive techniques can be applied, and therefore this review focusses on early caries involving the enamel surface of the tooth. The cornerstone of caries detection and diagnosis is a visual and tactile dental examination, although alternative approaches are available. These include illumination-based devices that could potentially support the dental examination. There are three categories of illumination devices that exploit various methods of application and interpretation, each primarily defined by different wavelengths, optical coherence tomography (OCT), near-infrared (NIR), and fibre-optic technology, which incorporates more recently developed digital fibre optics (FOTI/DIFOTI). OBJECTIVES: To estimate the diagnostic test accuracy of different illumination tests for the detection and diagnosis of enamel caries in children or adults. We also planned to explore the following potential sources of heterogeneity: in vitro or in vivo studies with different reference standards; tooth surface (occlusal, proximal, smooth surface, or adjacent to a restoration); single or multiple sites of assessment on a tooth surface; and the prevalence of caries into dentine. SEARCH METHODS: Cochrane Oral Health's Information Specialist undertook a search of the following databases: MEDLINE Ovid (1946 to 15 February 2019); Embase Ovid (1980 to 15 February 2019); US National Institutes of Health Ongoing Trials Register (ClinicalTrials.gov, to 15 February 2019); and the World Health Organization International Clinical Trials Registry Platform (to 15 February 2019). We studied reference lists as well as published systematic review articles. SELECTION CRITERIA: We included diagnostic accuracy study designs that compared the use of illumination-based devices with a reference standard (histology, enhanced visual examination with or without radiographs, or operative excavation). These included prospective studies that evaluated the diagnostic accuracy of a single index test and studies that directly compared two or more index tests. Both in vitro and in vivo studies of primary and permanent teeth were eligible for inclusion. We excluded studies that explicitly recruited participants with caries into dentine or frank cavitation. We also excluded studies that artificially created carious lesions and those that used an index test during the excavation of dental caries to ascertain the optimum depth of excavation. DATA COLLECTION AND ANALYSIS: Two review authors extracted data independently and in duplicate using a standardised data extraction form and quality assessment based on QUADAS-2 specific to the clinical context. Estimates of diagnostic accuracy were determined using the bivariate hierarchical method to produce summary points of sensitivity and specificity with 95% confidence regions. The comparative accuracy of different illumination devices was conducted based on indirect and direct comparisons between methods. Potential sources of heterogeneity were pre-specified and explored visually and more formally through meta-regression. MAIN RESULTS: We included 24 datasets from 23 studies that evaluated 16,702 tooth surfaces. NIR was evaluated in 6 datasets (673 tooth surfaces), OCT in 10 datasets (1171 tooth surfaces), and FOTI/DIFOTI in 8 datasets (14,858 tooth surfaces). The participant selection domain had the largest number of studies judged at high risk of bias (16 studies). Conversely, for the index test, reference standard, and flow and timing domains the majority of studies were judged to be at low risk of bias (16, 12, and 16 studies respectively). Concerns regarding the applicability of the evidence were judged as high or unclear for all domains. Notably, 14 studies were judged to be of high concern for participant selection, due to selective participant recruitment, a lack of independent examiners, and the use of an in vitro study design. The summary estimate across all the included illumination devices was sensitivity 0.75 (95% confidence interval (CI) 0.62 to 0.85) and specificity 0.87 (95% CI 0.82 to 0.92), with a diagnostic odds ratio of 21.52 (95% CI 10.89 to 42.48). In a cohort of 1000 tooth surfaces with a prevalence of enamel caries of 57%, this would result in 142 tooth surfaces being classified as disease free when enamel caries was truly present (false negatives), and 56 tooth surfaces being classified as diseased in the absence of enamel caries (false positives). A formal comparison of the accuracy according to device type indicated a difference in sensitivity and/or specificity (Chi2(4) = 34.17, P < 0.01). Further analysis indicated a difference in the sensitivity of the different devices (Chi2(2) = 31.24, P < 0.01) with a higher sensitivity of 0.94 (95% CI 0.88 to 0.97) for OCT compared to NIR 0.58 (95% CI 0.46 to 0.68) and FOTI/DIFOTI 0.47 (95% CI 0.35 to 0.59), but no meaningful difference in specificity (Chi2(2) = 3.47, P = 0.18). In light of these results, we planned to formally assess potential sources of heterogeneity according to device type, but due to the limited number of studies for each device type we were unable to do so. For interpretation, we presented the coupled forest plots for each device type according to the potential source of heterogeneity. We rated the certainty of the evidence as low and downgraded two levels in total due to avoidable and unavoidable study limitations in the design and conduct of studies, indirectness arising from the in vitro studies, and imprecision of the estimates. AUTHORS' CONCLUSIONS: Of the devices evaluated, OCT appears to show the most potential, with superior sensitivity to NIR and fibre-optic devices. Its benefit lies as an add-on tool to support the conventional oral examination to confirm borderline cases in cases of clinical uncertainty. OCT is not currently available to the general dental practitioner, and so further research and development are necessary. FOTI and NIR are more readily available and easy to use; however, they show limitations in their ability to detect enamel caries but may be considered successful in the identification of sound teeth. Future studies should strive to avoid research waste by ensuring that recruitment is conducted in such a way as to minimise selection bias and that studies are clearly and comprehensively reported. In terms of applicability, any future studies should be undertaken in a clinical setting that is reflective of the complexities encountered in caries assessment within the oral cavity.


Assuntos
Cárie Dentária/diagnóstico , Tecnologia de Fibra Óptica , Espectroscopia de Luz Próxima ao Infravermelho , Tomografia de Coerência Óptica , Transiluminação/métodos , Conjuntos de Dados como Assunto , Esmalte Dentário , Reações Falso-Negativas , Reações Falso-Positivas , Humanos , Padrões de Referência , Viés de Seleção , Sensibilidade e Especificidade
7.
Cochrane Database Syst Rev ; 12: CD012874, 2020 12 08.
Artigo em Inglês | MEDLINE | ID: mdl-33316105

RESUMO

BACKGROUND: Many surgeons prefer to perform total knee replacement surgery with the aid of a tourniquet. A tourniquet is an occlusive device that restricts distal blood flow to help create a bloodless field during the procedure. A tourniquet may be associated with increased risk of pain and complications. OBJECTIVES: To determine the benefits and harms of tourniquet use in knee replacement surgery. SEARCH METHODS: We searched MEDLINE, Embase, and Cochrane Central Register of Controlled Trials (CENTRAL) up to 26 March 2020. We searched clinicaltrials.gov, the World Health Organization trials portal, and several international registries and joint registries up to March 2020. SELECTION CRITERIA: We included randomised controlled trials (RCTs) comparing knee replacement with use of a tourniquet versus without use of a tourniquet and non-randomised studies with more than 1000 participants. Major outcomes included pain, function, global assessment of success, health-related quality of life, serious adverse events (including venous thromboembolism, infection, re-operation, and mortality), cognitive function, and survival of the implant. Minor outcomes included blood loss, economic outcomes, implant stability, and adverse events. DATA COLLECTION AND ANALYSIS: Two review authors screened abstracts and full texts, extracted data, performed risk of bias assessments, and assessed the certainty of the evidence using the GRADE approach. MAIN RESULTS: We included 41 RCTs with 2819 participants. Trials included from 20 to 199 participants. Mean age ranged between 58 and 84 years. More than half of the RCTs had unclear risk of selection bias and unclear risk of performance and detection bias due to absence of blinding of participants and surgeons. Major outcomes Pain: at postoperative day 1, pain (on a scale from zero to 10, with higher scores indicating worse pain) was ranked at 4.56 points after surgery without a tourniquet and at 1.25 points (MD) higher (95% CI 0.32 higher to 2.19 higher) with a tourniquet (8 studies; 577 participants), for an absolute difference of 12.5% higher pain scores (95% CI 3.2% higher to 21.9% higher) and a relative difference of 19% higher pain scores (95% CI 3.4% higher to 49% higher) with a tourniquet. Evidence for these findings was of moderate certainty, downgraded due to risk of bias. Knee replacement with a tourniquet probably led to higher postoperative pain scores at day 1, although this difference may or may not be noticeable to patients (based on a minimal clinically important difference (MCID) of 1.0). Function: at 12 months, tourniquet use probably makes little or no difference to function, based on an MCID of 5.3 for Knee Society Score (KSS) and 5.0 for Oxford Knee Score (OKS). Mean function (on a scale from 0 to 100, with higher scores indicating better outcomes) was 90.03 points after surgery without a tourniquet and was 0.29 points worse (95% CI 1.06 worse to 0.48 better) on a 0 to 100 scale, absolute difference was 0.29% worse (1.06% worse to 0.48% better), with a tourniquet (5 studies; 611 participants). This evidence was downgraded to moderate certainty due to risk of bias. Global assessment of success: low-certainty evidence (downgraded due to bias and imprecision) indicates that tourniquet use may have little or no effect on success. At six months, 47 of 50 (or 940 per 1000) reported overall successful treatment after surgery without a tourniquet and 47 of 50 (or 940 per 1000) with a tourniquet (risk ratio (RR) 1.0, 95% CI 0.91 to 1.10) based on one study with 100 participants. Health-related quality of life: at six months, tourniquet may have little or no effect on quality of life. The 12-Item Short Form Survey (SF-12) score (mental component from zero to 100 (100 is best)) was 54.64 after surgery without a tourniquet and 1.53 (MD) better (95% CI 0.85 worse to 3.91 better) with a tourniquet (1 study; 199 participants); absolute difference was 1.53% better (0.85% worse to 3.91% better). Evidence was of low certainty, downgraded due to risk of bias and small number of participants. Serious adverse events: the risk of serious adverse events was probably higher with tourniquet; 26 of 898 (29 per 1000) reported events following surgery without a tourniquet compared to 53 of 901 (59 per 1000) with a tourniquet (RR 1.73, 95% CI 1.10 to 2.73) in 21 studies (1799 participants). Twenty-nine more per 1000 patients (95% CI 3 to 50 more per 1000 patients) had a serious adverse event with a tourniquet. Forty-eight (95% CI 20 to 345) participants would need to have surgery without a tourniquet to avoid one serious adverse event. This evidence was downgraded to moderate certainty due to risk of bias. Cognitive function: one study reported cognitive function as an outcome; however the data were incompletely reported and could not be extracted for analysis. Survival of implant: it is uncertain if tourniquet has an effect on implant survival due to very low certainty evidence (downgraded for bias, and twice due to very low event rates); 2 of 107 (19 per 1000) required revision surgery in the surgery with a tourniquet group compared to 1 of 107 (9 per 1000) without a tourniquet group at up to two years' follow-up (RR 1.44, 95% CI 0.23 to 8.92). This equates to a 0.4% (0.7% lower to 7% more) increased absolute risk in surgery with a tourniquet. AUTHORS' CONCLUSIONS: Moderate certainty evidence shows that knee replacement surgery with a tourniquet is probably associated with an increased risk of serious adverse events. Surgery with a tourniquet is also probably associated with higher postoperative pain, although this difference may or may not be noticeable to patients. Surgery with a tourniquet does not appear to confer any clinically meaningful benefit on function, treatment success or quality of life. Further research is required to explore the effects of tourniquet use on cognitive function and implant survival, to identify any additional harms or benefits. If a tourniquet continues to be used in knee replacement surgery, patients should be informed about the potential increased risk of serious adverse events and postoperative pain.


Assuntos
Artroplastia do Joelho/efeitos adversos , Torniquetes/efeitos adversos , Idoso , Idoso de 80 Anos ou mais , Artroplastia do Joelho/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Medição da Dor/métodos , Dor Pós-Operatória/diagnóstico , Falha de Prótese , Qualidade de Vida , Ensaios Clínicos Controlados Aleatórios como Assunto , Viés de Seleção , Resultado do Tratamento
8.
Zhonghua Liu Xing Bing Xue Za Zhi ; 41(12): 2149-2159, 2020 Dec 10.
Artigo em Chinês | MEDLINE | ID: mdl-33378831

RESUMO

This paper introduces the conducting systematic reviews and Meta-analyses of observational studies of etiology (COSMOS-E) and illustrates the critical issues of COSMOS-E with a published systematic review. This document provides researchers with guidance on all steps in systematic reviews of observational studies of etiology, from shaping the research question, defining exposure and outcomes, to assessing the risk of bias and statistical analysis.


Assuntos
Metanálise como Assunto , Estudos Observacionais como Assunto , Revisões Sistemáticas como Assunto , Humanos , Estudos Observacionais como Assunto/métodos , Estudos Observacionais como Assunto/normas , Viés de Seleção
9.
Cochrane Database Syst Rev ; 10: CD002271, 2020 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-33058208

RESUMO

BACKGROUND: Respiratory distress, particularly respiratory distress syndrome (RDS), is the single most important cause of morbidity and mortality in preterm infants. In infants with progressive respiratory insufficiency, intermittent positive pressure ventilation (IPPV) with surfactant has been the usual treatment, but it is invasive, potentially resulting in airway and lung injury. Continuous positive airway pressure (CPAP) has been used for the prevention and treatment of respiratory distress, as well as for the prevention of apnoea, and in weaning from IPPV. Its use in the treatment of RDS might reduce the need for IPPV and its sequelae. OBJECTIVES: To determine the effect of continuous distending pressure in the form of CPAP on the need for IPPV and associated morbidity in spontaneously breathing preterm infants with respiratory distress. SEARCH METHODS: We used the standard strategy of Cochrane Neonatal to search CENTRAL (2020, Issue 6); Ovid MEDLINE and Epub Ahead of Print, In-Process & Other Non-Indexed Citations, Daily and Versions; and CINAHL on 30 June 2020. We also searched clinical trials databases and the reference lists of retrieved articles for randomised controlled trials and quasi-randomised trials. SELECTION CRITERIA: All randomised or quasi-randomised trials of preterm infants with respiratory distress were eligible. Interventions were CPAP by mask, nasal prong, nasopharyngeal tube or endotracheal tube, compared with spontaneous breathing with supplemental oxygen as necessary. DATA COLLECTION AND ANALYSIS: We used standard methods of Cochrane and its Neonatal Review Group, including independent assessment of risk of bias and extraction of data by two review authors. We used the GRADE approach to assess the certainty of evidence. Subgroup analyses were planned on the basis of birth weight (greater than or less than 1000 g or 1500 g), gestational age (groups divided at about 28 weeks and 32 weeks), timing of application (early versus late in the course of respiratory distress), pressure applied (high versus low) and trial setting (tertiary compared with non-tertiary hospitals; high income compared with low income) MAIN RESULTS: We included five studies involving 322 infants; two studies used face mask CPAP, two studies used nasal CPAP and one study used endotracheal CPAP and continuing negative pressure for a small number of less ill babies. For this update, we included one new trial. CPAP was associated with lower risk of treatment failure (death or use of assisted ventilation) (typical risk ratio (RR) 0.64, 95% confidence interval (CI) 0.50 to 0.82; typical risk difference (RD) -0.19, 95% CI -0.28 to -0.09; number needed to treat for an additional beneficial outcome (NNTB) 6, 95% CI 4 to 11; I2 = 50%; 5 studies, 322 infants; very low-certainty evidence), lower use of ventilatory assistance (typical RR 0.72, 95% CI 0.54 to 0.96; typical RD -0.13, 95% CI -0.25 to -0.02; NNTB 8, 95% CI 4 to 50; I2 = 55%; very low-certainty evidence) and lower overall mortality (typical RR 0.53, 95% CI 0.34 to 0.83; typical RD -0.11, 95% CI -0.18 to -0.04; NNTB 9, 95% CI 2 to 13; I2 = 0%; 5 studies, 322 infants; moderate-certainty evidence). CPAP was associated with increased risk of pneumothorax (typical RR 2.48, 95% CI 1.16 to 5.30; typical RD 0.09, 95% CI 0.02 to 0.16; number needed to treat for an additional harmful outcome (NNTH) 11, 95% CI 7 to 50; I2 = 0%; 4 studies, 274 infants; low-certainty evidence). There was no evidence of a difference in bronchopulmonary dysplasia, defined as oxygen dependency at 28 days (RR 1.04, 95% CI 0.35 to 3.13; I2 = 0%; 2 studies, 209 infants; very low-certainty evidence). The trials did not report use of surfactant, intraventricular haemorrhage, retinopathy of prematurity, necrotising enterocolitis and neurodevelopment outcomes in childhood. AUTHORS' CONCLUSIONS: In preterm infants with respiratory distress, the application of CPAP is associated with reduced respiratory failure, use of mechanical ventilation and mortality and an increased rate of pneumothorax compared to spontaneous breathing with supplemental oxygen as necessary. Three out of five of these trials were conducted in the 1970s. Therefore, the applicability of these results to current practice is unclear. Further studies in resource-poor settings should be considered and research to determine the most appropriate pressure level needs to be considered.


Assuntos
Pressão Positiva Contínua nas Vias Aéreas/métodos , Recém-Nascido Prematuro , Síndrome do Desconforto Respiratório do Recém-Nascido/terapia , Displasia Broncopulmonar/etiologia , Pressão Positiva Contínua nas Vias Aéreas/efeitos adversos , Humanos , Recém-Nascido de Baixo Peso , Recém-Nascido , Ventilação com Pressão Positiva Intermitente/efeitos adversos , Avaliação de Resultados em Cuidados de Saúde , Pneumotórax/etiologia , Surfactantes Pulmonares/uso terapêutico , Ensaios Clínicos Controlados Aleatórios como Assunto , Síndrome do Desconforto Respiratório do Recém-Nascido/mortalidade , Insuficiência Respiratória/prevenção & controle , Viés de Seleção , Falha de Tratamento
10.
Gac. sanit. (Barc., Ed. impr.) ; 34(5): 518-520, sept.-oct. 2020. tab
Artigo em Espanhol | IBECS | ID: ibc-198876

RESUMO

El uso de estudios basados en encuestas online se ha extendido de manera notable. A pesar de tener tasas de respuesta especialmente pequeñas, permiten obtener con facilidad un gran tamaño de muestra. Sin embargo, esta estrategia puede conllevar un sesgo de selección que comprometa notablemente los resultados. Se comparan los resultados de dos encuestas sobre la regulación de la eutanasia y el suicidio asistido, una online con muestra autoseleccionada y la otra con muestreo aleatorio, realizadas en 2018 entre los/las colegiados/as del Colegio de Médicos de Bizkaia. Las tasas de respuesta fueron del 10,4% (encuesta online) y del 87,8% (encuesta aleatoria). No se encontraron diferencias en las características sociodemográficas, aunque sí en las de opinión, de manera que el porcentaje de personas contrarias a la regulación de la eutanasia estaba sobrestimado. Los resultados de este estudio muestran que dicha estrategia de muestreo genera sesgos en los resultados, alguno de ellos difícilmente detectable y reparable


The use of studies based on online surveys has expanded significantly. Despite having particularly small response rates, they allow a large sample size to be easily obtained. However, this strategy may entail a selection bias that significantly compromises the results. The results of two surveys on the regulation of euthanasia and assisted suicide are compared. One is an online survey with a self-selected sample and the other a survey with random sampling, conducted in 2018 among the members of the Medical Association of Bizkaia. The response rates were 10.4% (online survey) and 87.8% (random survey). No differences were found in sociodemographic characteristics, although there were differences in the opinion variables, so that the percentage of people who opposed euthanasia regulation was overestimated. The results of this study show that this sampling strategy generates biases in the results, some of which are difficult both to detect and to repair


Assuntos
Humanos , Inquéritos e Questionários/classificação , Suicídio Assistido/estatística & dados numéricos , Eutanásia/estatística & dados numéricos , Acesso à Internet/estatística & dados numéricos , Viés de Seleção , Tamanho da Amostra , Coleta de Dados/métodos , Reprodutibilidade dos Testes
11.
J Adolesc Health ; 67(5): 645-648, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32933837

RESUMO

PURPOSE: The abrupt closure of universities across the U.S. in March 2020 may have sent some lesbian, gay, bisexual, and transgender (LGBT) college students home to unsafe or unaccepting families and environments. The objective of this study was to examine the mental health needs of LGBT college students in the U.S. during the COVID-19 pandemic. METHODS: We fielded a rapid-response online survey in the spring of 2020. We recruited 477 LGBT-identifying college students aged 18-25 years by contacting LGBT-serving organizations on 254 college campuses and through targeted social media advertising. RESULTS: Nearly half (45.7%) of LGBT college students have immediate families that do not support or know their LGBT identity. Approximately 60% of sampled LGBT college students were experiencing psychological distress, anxiety, and depression during the pandemic. CONCLUSIONS: Health-care providers, college and university administrators, and campus counseling centers should take swift action to ensure that LGBT students receive mental health support during the pandemic.


Assuntos
Infecções por Coronavirus/psicologia , Necessidades e Demandas de Serviços de Saúde/estatística & dados numéricos , Serviços de Saúde Mental , Pneumonia Viral/psicologia , Minorias Sexuais e de Gênero/psicologia , Serviços de Saúde para Estudantes , Adolescente , Adulto , Feminino , Acesso aos Serviços de Saúde/economia , Humanos , Masculino , Pandemias , Viés de Seleção , Comportamento Sexual , Inquéritos e Questionários , Pessoas Transgênero/psicologia , Estados Unidos , Universidades , Adulto Jovem
14.
J Environ Manage ; 272: 110996, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32854899

RESUMO

Woodchip bioreactors are a practical, low-cost technology for reducing nitrate (NO3) loads discharged from agriculture. Traditional methods of quantifying their performance in the field mostly rely on low-frequency, time-based (weekly to monthly sampling interval) or flow-weighted sample collection at the inlet and outlet, creating uncertainty in their performance and design by providing incomplete information on flow and water chemistry. To address this uncertainty, two field bioreactors were monitored in the US and New Zealand using high-frequency, multipoint sampling for in situ monitoring of NO3-N concentrations. High-frequency monitoring (sub hourly interval) at the inlet and outlet of both bioreactors revealed significant variability in volumetric removal rates and percent reduction, with percent reduction varying by up to 25 percentage points within a single flow event. Time series of inlet and outlet NO3 showed significant lag in peak concentrations of 1-3 days due to high hydraulic residence time, where calculations from instantaneous measurements produced erroneous estimates of performance and misleading relationships between residence time and removal. Internal porewater sampling wells showed differences in NO3 concentration between shallow and deep zones, and "hot spot" zones where peak NO3 removal co-occurred with dissolved oxygen depletion and dissolved organic carbon production. Tracking NO3 movement through the profile showed preferential flow occurring with slower flow in deeper woodchips, and slower flow further from the most direct flowpath from inlet to outlet. High-frequency, in situ data on inlet and outlet time series and internal porewater solute profiles of this initial work highlight several key areas for future research.


Assuntos
Reatores Biológicos , Desnitrificação , Nova Zelândia , Nitratos/análise , Viés de Seleção
15.
Z Evid Fortbild Qual Gesundhwes ; 156-157: 68-74, 2020 Nov.
Artigo em Alemão | MEDLINE | ID: mdl-32855075

RESUMO

BACKGROUND: The creation of control groups in the evaluation of statutory health insurances is a key issue. Randomization represents both an ethical and a legal problem with legally guaranteed services. Matching procedures are relevant alternatives in the construction of control groups. Matchings are mostly based on secondary data from statutory health insurances (for example age, gender, cost of illness, days of incapacity to work). In this study, we examined whether matching based on secondary data alone can cause selection bias. METHODS: We used data from three large prevention studies and applied sensitivity analyses to compare the results of propensity score matchings used to create control groups on the basis of secondary data, with those obtained on the basis of both primary and secondary data. Analysis of covariance was used to investigate the impact of potential selection bias on cost effects. RESULTS: Matchings based on secondary data alone lead to control groups with similar characteristics captured by secondary data. However, the control group participants are significantly healthier (they have, for example, lower levels of pain, lower levels of psychological stress, a higher degree of quality of life) than the patients in intervention groups. This selection bias would lead to a systematic underestimation of the cost reduction produced by preventive interventions. DISCUSSION: Prevention course participants seem to have characteristics that differ from the average population (higher health orientation level, preference for prevention over medical treatment services, etc.) and cannot be captured by secondary data; therefore, matchings based on secondary data alone cause selection bias. CONCLUSIONS: Including both primary and secondary data reduces the risk of selection bias in matching procedures for prevention studies. The E-value can be used to evaluate the robustness of results with regard to selection bias.


Assuntos
Qualidade de Vida , Grupos Controle , Alemanha , Humanos , Pontuação de Propensão , Viés de Seleção
16.
JAMA ; 324(6): 581-593, 2020 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-32730561

RESUMO

Importance: Nonoperative management with antibiotics alone has the potential to treat uncomplicated pediatric appendicitis with fewer disability days than surgery. Objective: To determine the success rate of nonoperative management and compare differences in treatment-related disability, satisfaction, health-related quality of life, and complications between nonoperative management and surgery in children with uncomplicated appendicitis. Design, Setting, and Participants: Multi-institutional nonrandomized controlled intervention study of 1068 children aged 7 through 17 years with uncomplicated appendicitis treated at 10 tertiary children's hospitals across 7 US states between May 2015 and October 2018 with 1-year follow-up through October 2019. Of the 1209 eligible patients approached, 1068 enrolled in the study. Interventions: Patient and family selection of nonoperative management with antibiotics alone (nonoperative group, n = 370) or urgent (≤12 hours of admission) laparoscopic appendectomy (surgery group, n = 698). Main Outcomes and Measures: The 2 primary outcomes assessed at 1 year were disability days, defined as the total number of days the child was not able to participate in all of his/her normal activities secondary to appendicitis-related care (expected difference, 5 days), and success rate of nonoperative management, defined as the proportion of patients initially managed nonoperatively who did not undergo appendectomy by 1 year (lowest acceptable success rate, ≥70%). Inverse probability of treatment weighting (IPTW) was used to adjust for differences between treatment groups for all outcome assessments. Results: Among 1068 patients who were enrolled (median age, 12.4 years; 38% girls), 370 (35%) chose nonoperative management and 698 (65%) chose surgery. A total of 806 (75%) had complete follow-up: 284 (77%) in the nonoperative group; 522 (75%) in the surgery group. Patients in the nonoperative group were more often younger (median age, 12.3 years vs 12.5 years), Black (9.6% vs 4.9%) or other race (14.6% vs 8.7%), had caregivers with a bachelor's degree (29.8% vs 23.5%), and underwent diagnostic ultrasound (79.7% vs 74.5%). After IPTW, the success rate of nonoperative management at 1 year was 67.1% (96% CI, 61.5%-72.31%; P = .86). Nonoperative management was associated with significantly fewer patient disability days at 1 year than did surgery (adjusted mean, 6.6 vs 10.9 days; mean difference, -4.3 days (99% CI, -6.17 to -2.43; P < .001). Of 16 other prespecified secondary end points, 10 showed no significant difference. Conclusion and Relevance: Among children with uncomplicated appendicitis, an initial nonoperative management strategy with antibiotics alone had a success rate of 67.1% and, compared with urgent surgery, was associated with statistically significantly fewer disability days at 1 year. However, there was substantial loss to follow-up, the comparison with the prespecified threshold for an acceptable success rate of nonoperative management was not statistically significant, and the hypothesized difference in disability days was not met. Trial Registration: ClinicalTrials.gov Identifier: NCT02271932.


Assuntos
Antibacterianos/uso terapêutico , Apendicectomia , Apendicite/tratamento farmacológico , Apendicite/cirurgia , Doença Aguda , Adolescente , Apendicectomia/métodos , Apendicite/diagnóstico por imagem , Apêndice/diagnóstico por imagem , Criança , Feminino , Seguimentos , Humanos , Laparoscopia , Masculino , Pontuação de Propensão , Qualidade de Vida , Viés de Seleção , Tomografia Computadorizada por Raios X , Resultado do Tratamento , Ultrassonografia
17.
Cochrane Database Syst Rev ; 7: CD013665, 2020 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-32633856

RESUMO

BACKGROUND: Some people with SARS-CoV-2 infection remain asymptomatic, whilst in others the infection can cause mild to moderate COVID-19 disease and COVID-19 pneumonia, leading some patients to require intensive care support and, in some cases, to death, especially in older adults. Symptoms such as fever or cough, and signs such as oxygen saturation or lung auscultation findings, are the first and most readily available diagnostic information. Such information could be used to either rule out COVID-19 disease, or select patients for further diagnostic testing. OBJECTIVES: To assess the diagnostic accuracy of signs and symptoms to determine if a person presenting in primary care or to hospital outpatient settings, such as the emergency department or dedicated COVID-19 clinics, has COVID-19 disease or COVID-19 pneumonia. SEARCH METHODS: On 27 April 2020, we undertook electronic searches in the Cochrane COVID-19 Study Register and the University of Bern living search database, 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: Studies were eligible if they included patients with suspected COVID-19 disease, or if they recruited known cases with COVID-19 disease and controls without COVID-19. Studies were eligible when they recruited patients presenting to primary care or hospital outpatient settings. Studies including patients who contracted SARS-CoV-2 infection while admitted to hospital were not eligible. The minimum eligible sample size of studies was 10 participants. All signs and symptoms were eligible for this review, including individual signs and symptoms or combinations. We accepted a range of reference standards including reverse transcription polymerase chain reaction (RT-PCR), clinical expertise, imaging, serology tests and World Health Organization (WHO) or other definitions of COVID-19. DATA COLLECTION AND ANALYSIS: Pairs of review authors independently selected all studies, at both title and abstract stage and full-text stage. They resolved any disagreements by discussion with a third review author. Two review authors independently extracted data and resolved disagreements by discussion with a third review author. Two review authors independently assessed risk of bias using the QUADAS-2 checklist. Analyses were descriptive, presenting sensitivity and specificity in paired forest plots, in ROC (receiver operating characteristic) space and in dumbbell plots. We did not attempt meta-analysis due to the small number of studies, heterogeneity across studies and the high risk of bias. MAIN RESULTS: We identified 16 studies including 7706 participants in total. Prevalence of COVID-19 disease varied from 5% to 38% with a median of 17%. There were no studies from primary care settings, although we did find seven studies in outpatient clinics (2172 participants), and four studies in the emergency department (1401 participants). We found data on 27 signs and symptoms, which fall into four different categories: systemic, respiratory, gastrointestinal and cardiovascular. No studies assessed combinations of different signs and symptoms and results were highly variable across studies. Most had very low sensitivity and high specificity; only six symptoms had a sensitivity of at least 50% in at least one study: cough, sore throat, fever, myalgia or arthralgia, fatigue, and headache. Of these, fever, myalgia or arthralgia, fatigue, and headache could be considered red flags (defined as having a positive likelihood ratio of at least 5) for COVID-19 as their specificity was above 90%, meaning that they substantially increase the likelihood of COVID-19 disease when present. Seven studies carried a high risk of bias for selection of participants because inclusion in the studies depended on the applicable testing and referral protocols, which included many of the signs and symptoms under study in this review. Five studies only included participants with pneumonia on imaging, suggesting that this is a highly selected population. In an additional four studies, we were unable to assess the risk for selection bias. These factors make it very difficult to determine the diagnostic properties of these signs and symptoms from the included studies. We also had concerns about the applicability of these results, since most studies included participants who were already admitted to hospital or presenting to hospital settings. This makes these findings less applicable to people presenting to primary care, who may have less severe illness and a lower prevalence of COVID-19 disease. None of the studies included any data on children, and only one focused specifically on older adults. We hope that future updates of this review will be able to provide more information about the diagnostic properties of signs and symptoms in different settings and age groups. AUTHORS' CONCLUSIONS: The individual signs and symptoms included in this review appear to have very poor diagnostic properties, although this should be interpreted in the context of selection bias and heterogeneity between studies. Based on currently available data, neither absence nor presence of signs or symptoms are accurate enough to rule in or rule out disease. Prospective studies in an unselected population presenting to primary care or hospital outpatient settings, examining combinations of signs and symptoms to evaluate the syndromic presentation of COVID-19 disease, are urgently needed. Results from such studies could inform subsequent management decisions such as self-isolation or selecting patients for further diagnostic testing. We also need data on potentially more specific symptoms such as loss of sense of smell. Studies in older adults are especially important.


Assuntos
Assistência Ambulatorial , Betacoronavirus , Infecções por Coronavirus/diagnóstico , Pneumonia Viral/diagnóstico , Atenção Primária à Saúde , Avaliação de Sintomas , Artralgia/diagnóstico , Artralgia/etiologia , Infecções por Coronavirus/complicações , Infecções por Coronavirus/epidemiologia , Fadiga/diagnóstico , Fadiga/etiologia , Febre/diagnóstico , Febre/etiologia , Cefaleia/diagnóstico , Humanos , Mialgia/diagnóstico , Mialgia/etiologia , Ambulatório Hospitalar/estatística & dados numéricos , Pandemias , Exame Físico , Pneumonia Viral/complicações , Pneumonia Viral/epidemiologia , Viés de Seleção , Avaliação de Sintomas/classificação , Avaliação de Sintomas/estatística & dados numéricos
18.
Cochrane Database Syst Rev ; 7: CD013600, 2020 07 10.
Artigo em Inglês | MEDLINE | ID: mdl-32648959

RESUMO

BACKGROUND: Convalescent plasma and hyperimmune immunoglobulin may reduce mortality in patients with viral respiratory diseases, and are currently being investigated in trials as potential therapy for coronavirus disease 2019 (COVID-19). A thorough understanding of the current body of evidence regarding the benefits and risks is required.  OBJECTIVES: To continually assess, as more evidence becomes available, whether convalescent plasma or hyperimmune immunoglobulin transfusion is effective and safe in treatment of people with COVID-19. SEARCH METHODS: We searched the World Health Organization (WHO) COVID-19 Global Research Database, MEDLINE, Embase, Cochrane COVID-19 Study Register, Centers for Disease Control and Prevention COVID-19 Research Article Database and trial registries to identify completed and ongoing studies on 4 June 2020. SELECTION CRITERIA: We followed standard Cochrane methodology. We included studies evaluating convalescent plasma or hyperimmune immunoglobulin for people with COVID-19, irrespective of study design, disease severity, age, gender or ethnicity. We excluded studies including populations with other coronavirus diseases (severe acute respiratory syndrome (SARS) or Middle East respiratory syndrome (MERS)) and studies evaluating standard immunoglobulin. DATA COLLECTION AND ANALYSIS: We followed standard Cochrane methodology. To assess bias in included studies, we used the Cochrane 'Risk of bias' tool for randomised controlled trials (RCTs), the Risk of Bias in Non-randomised Studies - of Interventions (ROBINS-I) tool for controlled non-randomised studies of interventions (NRSIs), and the assessment criteria for observational studies, provided by Cochrane Childhood Cancer for non-controlled NRSIs.  MAIN RESULTS: This is the first living update of our review. We included 20 studies (1 RCT, 3 controlled NRSIs, 16 non-controlled NRSIs) with 5443 participants, of whom 5211 received convalescent plasma, and identified a further 98 ongoing studies evaluating convalescent plasma or hyperimmune immunoglobulin, of which 50 are randomised. We did not identify any completed studies evaluating hyperimmune immunoglobulin. Overall risk of bias of included studies was high, due to study design, type of participants, and other previous or concurrent treatments. Effectiveness of convalescent plasma for people with COVID-19  We included results from four controlled studies (1 RCT (stopped early) with 103 participants, of whom 52 received convalescent plasma; and 3 controlled NRSIs with 236 participants, of whom 55 received convalescent plasma) to assess effectiveness of convalescent plasma. Control groups received standard care at time of treatment without convalescent plasma. All-cause mortality at hospital discharge (1 controlled NRSI, 21 participants) We are very uncertain whether convalescent plasma has any effect on all-cause mortality at hospital discharge (risk ratio (RR) 0.89, 95% confidence interval (CI) 0.61 to 1.31; very low-certainty evidence). Time to death (1 RCT, 103 participants; 1 controlled NRSI, 195 participants) We are very uncertain whether convalescent plasma prolongs time to death (RCT: hazard ratio (HR) 0.74, 95% CI 0.30 to 1.82; controlled NRSI: HR 0.46, 95% CI 0.22 to 0.96; very low-certainty evidence). Improvement of clinical symptoms, assessed by need for respiratory support (1 RCT, 103 participants; 1 controlled NRSI, 195 participants) We are very uncertain whether convalescent plasma has any effect on improvement of clinical symptoms at seven days (RCT: RR 0.98, 95% CI 0.30 to 3.19), 14 days (RCT: RR 1.85, 95% CI 0.91 to 3.77; controlled NRSI: RR 1.08, 95% CI 0.91 to 1.29), and 28 days (RCT: RR 1.20, 95% CI 0.80 to 1.81; very low-certainty evidence). Quality of life No studies reported this outcome.  Safety of convalescent plasma for people with COVID-19 We included results from 1 RCT, 3 controlled NRSIs and 10 non-controlled NRSIs assessing safety of convalescent plasma. Reporting of adverse events and serious adverse events was variable. The controlled studies reported on adverse events and serious adverse events only in participants receiving convalescent plasma. The duration of follow-up varied. Some, but not all, studies included death as a serious adverse event.  Grade 3 or 4 adverse events (13 studies, 201 participants) The studies did not report the grade of adverse events. Thirteen studies (201 participants) reported on adverse events of possible grade 3 or 4 severity. The majority of these adverse events were allergic or respiratory events. We are very uncertain whether or not convalescent plasma therapy affects the risk of moderate to severe adverse events (very low-certainty evidence).  Serious adverse events (14 studies, 5201 participants)  Fourteen studies (5201 participants) reported on serious adverse events. The majority of participants were from one non-controlled NRSI (5000 participants), which reported only on serious adverse events limited to the first four hours after convalescent plasma transfusion. This study included death as a serious adverse event; they reported 15 deaths, four of which they classified as potentially, probably or definitely related to transfusion. Other serious adverse events reported in all studies were predominantly allergic or respiratory in nature, including anaphylaxis, transfusion-associated dyspnoea, and transfusion-related acute lung injury (TRALI). We are very uncertain whether or not convalescent plasma affects the number of serious adverse events. AUTHORS' CONCLUSIONS: We are very uncertain whether convalescent plasma is beneficial for people admitted to hospital with COVID-19. For safety outcomes we also included non-controlled NRSIs. There was limited information regarding adverse events. Of the controlled studies, none reported on this outcome in the control group. There is only very low-certainty evidence for safety of convalescent plasma for COVID-19.  While major efforts to conduct research on COVID-19 are being made, problems with recruiting the anticipated number of participants into these studies are conceivable. The early termination of the first RCT investigating convalescent plasma, and the multitude of studies registered in the past months illustrate this. It is therefore necessary to critically assess the design of these registered studies, and well-designed studies should be prioritised. Other considerations for these studies are the need to report outcomes for all study arms in the same way, and the importance of maintaining comparability in terms of co-interventions administered in all study arms.  There are 98 ongoing studies evaluating convalescent plasma and hyperimmune immunoglobulin, of which 50 are RCTs. This is the first living update of the review, and we will continue to update this review periodically. These updates may show different results to those reported here.


Assuntos
Betacoronavirus/imunologia , Infecções por Coronavirus/terapia , Pneumonia Viral/terapia , Causas de Morte , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/mortalidade , Término Precoce de Ensaios Clínicos , Humanos , Imunização Passiva/efeitos adversos , Imunização Passiva/métodos , Imunização Passiva/mortalidade , Imunização Passiva/estatística & dados numéricos , Ensaios Clínicos Controlados não Aleatórios como Assunto/mortalidade , Ensaios Clínicos Controlados não Aleatórios como Assunto/estatística & dados numéricos , Pandemias , Pneumonia Viral/imunologia , Pneumonia Viral/mortalidade , Ensaios Clínicos Controlados Aleatórios como Assunto/estatística & dados numéricos , Respiração Artificial/estatística & dados numéricos , Viés de Seleção , Índice de Gravidade de Doença , Resultado do Tratamento
19.
PLoS One ; 15(7): e0234877, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32649672

RESUMO

A critical component of textbooks is fair representation of the material they cover. Within conservation biology, fair coverage is particularly important given Earth's breadth of species and diversity of ecosystems. However, research on species tends to be biased towards certain taxonomic groups and geographic areas and their associated ecosystems, so it is possible that textbooks may exhibit similar biases. Considering the possibility of bias, our goal was to evaluate contemporary conservation biology textbooks to determine if they are representative of Earth's biodiversity. We found that textbooks did not accurately reflect Earth's biodiversity. Species, ecosystems, and continents were unevenly represented, few examples mentioned genetic diversity, and examples of negative human influence on the environment outweighed positive examples. However, in terms of aquatic versus terrestrial representation, textbooks presented a representative sample. Our findings suggest that modern conservation biology textbooks are biased in their coverage, which could have important consequences for educating our next generation of scientists and practitioners.


Assuntos
Viés , Conservação dos Recursos Naturais/métodos , Biodiversidade , Ecossistema , Humanos , Variações Dependentes do Observador , Viés de Seleção , Livros de Texto como Assunto
20.
Cochrane Database Syst Rev ; 6: CD013652, 2020 06 25.
Artigo em Inglês | MEDLINE | ID: mdl-32584464

RESUMO

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.


Assuntos
Anticorpos Antivirais/sangue , Betacoronavirus/imunologia , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/imunologia , Pneumonia Viral/diagnóstico , Pneumonia Viral/imunologia , Especificidade de Anticorpos , Infecções por Coronavirus/epidemiologia , Reações Falso-Negativas , Reações Falso-Positivas , Humanos , Imunoglobulina A/sangue , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Pandemias , Pneumonia Viral/epidemiologia , Padrões de Referência , Reação em Cadeia da Polimerase Via Transcriptase Reversa/normas , Reação em Cadeia da Polimerase Via Transcriptase Reversa/estatística & dados numéricos , Viés de Seleção , Sensibilidade e Especificidade , Testes Sorológicos/métodos , Testes Sorológicos/normas
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