scholarly journals Systematic reviews of observational studies of Risk of Thrombosis and Bleeding in General and Gynecologic Surgery (ROTBIGGS): introduction and methodology

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Lauri I. Lavikainen ◽  
Gordon H. Guyatt ◽  
Yung Lee ◽  
Rachel J. Couban ◽  
Anna L. Luomaranta ◽  
...  
Keyword(s):  
Systematic Reviews ◽  
Observational Studies ◽  
Risk Of Bias ◽  
Gynecologic Surgery ◽  
Patient Risk ◽  
Trade Off ◽  
Risk Estimates ◽  
Modeling Studies ◽  
Meta Analyses ◽  
Grade Approach

Abstract Background Venous thromboembolism (VTE) and bleeding are serious and potentially fatal complications of surgical procedures. Pharmacological thromboprophylaxis decreases the risk of VTE but increases the risk of major post-operative bleeding. The decision to use pharmacologic prophylaxis therefore represents a trade-off that critically depends on the incidence of VTE and bleeding in the absence of prophylaxis. These baseline risks vary widely between procedures, but their magnitude is uncertain. Systematic reviews addressing baseline risks are scarce, needed, and require innovations in methodology. Indeed, systematic summaries of these baseline risk estimates exist neither in general nor gynecologic surgery. We will fill this knowledge gap by performing a series of systematic reviews and meta-analyses of the procedure-specific and patient risk factor stratified risk estimates in general and gynecologic surgeries. Methods We will perform comprehensive literature searches for observational studies in general and gynecologic surgery reporting symptomatic VTE or bleeding estimates. Pairs of methodologically trained reviewers will independently assess the studies for eligibility, evaluate the risk of bias by using an instrument developed for this review, and extract data. We will perform meta-analyses and modeling studies to adjust the reported risk estimates for the use of thromboprophylaxis and length of follow up. We will derive the estimates of risk from the median estimates of studies rated at the lowest risk of bias. The primary outcomes are the risk estimates of symptomatic VTE and major bleeding at 4 weeks post-operatively for each procedure stratified by patient risk factors. We will apply the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach to rate evidence certainty. Discussion This series of systematic reviews, modeling studies, and meta-analyses will inform clinicians and patients regarding the trade-off between VTE prevention and bleeding in general and gynecologic surgeries. Our work advances the standards in systematic reviews of surgical complications, including assessment of risk of bias, criteria for arriving at the best estimates of risk (including modeling of the timing of events and dealing with suboptimal data reporting), dealing with subgroups at higher and lower risk of bias, and use of the GRADE approach. Systematic review registration PROSPERO CRD42021234119

scholarly journals The development of a new generic risk-of-bias measure for systematic reviews of surveys

Methodology ◽  
2020 ◽  
Vol 16 (4) ◽  
pp. 278-298
Author(s):  
Gabriel Nudelman ◽  
Kathleen Otto
Keyword(s):  
Pilot Study ◽  
Systematic Reviews ◽  
Convergent Validity ◽  
Meta Analysis ◽  
Weighted Kappa ◽  
Risk Of Bias ◽  
Interrater Agreement ◽  
Bias Measure ◽  
Meta Analyses ◽  
Initial List

It is important to evaluate risk of bias of the primary studies included in systematic reviews and meta-analyses. Since tools pertinent to surveys are scarce, the goal of the current research was to develop a measure to address this need. In Study 1, an initial list of 10 relevant topics was compiled from previous measures. In Study 2, the list was refined into an eight-item risk-of-bias measure via discussion and a pilot study. In Study 3, experienced researchers used the measure to asses 70 studies, demonstrating high interrater agreement (weighted Kappa = .82). Inexperienced raters also utilized the measure to code 26 different studies included in a prior meta-analysis, which resulted in adequate interrater agreement (weighted Kappa = .64) and excellent convergent validity (r = .66). Thus, the new measure, designed to be accessible and flexible, can increase standardization of risk-of-bias evaluations and contribute to the interpretation of systematic reviews and meta-analytic findings.

scholarly journals Processed Meat Consumption and the Risk of Cancer: A Critical Evaluation of the Constraints of Current Evidence from Epidemiological Studies

Nutrients ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 3601
Author(s):  
Mina Nicole Händel ◽  
Jeanett Friis Rohde ◽  
Ramune Jacobsen ◽  
Berit Lilienthal Heitmann
Keyword(s):  
General Population ◽  
Systematic Reviews ◽  
Methodological Quality ◽  
Meat Products ◽  
Meat Consumption ◽  
Risk Of Bias ◽  
Processed Meat ◽  
Meta Analyses ◽  
Risk Of Cancer ◽  
Processed Meat Consumption

Based on a large volume of observational scientific studies and many summary papers, a high consumption of meat and processed meat products has been suggested to have a harmful effect on human health. These results have led guideline panels worldwide to recommend to the general population a reduced consumption of processed meat and meat products, with the overarching aim of lowering disease risk, especially of cancer. We revisited and updated the evidence base, evaluating the methodological quality and the certainty of estimates in the published systematic reviews and meta-analyses that examined the association between processed meat consumption and the risk of cancer at different sites across the body, as well as the overall risk of cancer mortality. We further explored if discrepancies in study designs and risks of bias could explain the heterogeneity observed in meta-analyses. In summary, there are severe methodological limitations to the majority of the previously published systematic reviews and meta-analyses that examined the consumption of processed meat and the risk of cancer. Many lacked the proper assessment of the methodological quality of the primary studies they included, or the literature searches did not fulfill the methodological standards needed in order to be systematic and transparent. The primary studies included in the reviews had a potential risk for the misclassification of exposure, a serious risk of bias due to confounding, a moderate to serious risk of bias due to missing data, and/or a moderate to serious risk of selection of the reported results. All these factors may have potentially led to the overestimation of the risk related to processed meat intake across all cancer outcomes. Thus, with the aim of lowering the risk of cancer, the recommendation to reduce the consumption of processed meat and meat products in the general population seems to be based on evidence that is not methodologically strong.

Auriculoterapia para o tratamento da ansiedade em estudantes universitários: revisão sistemática

2021 ◽  
Author(s):  
◽  
Lara dos Santos Silva
Keyword(s):  
Clinical Trials ◽  
Systematic Reviews ◽  
Ad Hoc ◽  
Cochrane Collaboration ◽  
Risk Of Bias ◽  
Meta Analyses ◽  
Tecnología Educativa

A ansiedade está entre os transtornos mentais de maior prevalência na população mundial, sendo a segunda causa de incapacidade mental no mundo. Dentre a população suscetível à ansiedade, destacam-se os estudantes universitários, em decorrência das situações vivenciadas no âmbito acadêmico. Os tratamentos da ansiedade podem estar pautados em recursos medicamentosos e não medicamentosos. Dentre os não medicamentosos, destacam-se as Práticas Integrativas e Complementares em Saúde e, dentre estas, a auriculoterapia. O objetivo geral deste estudo foi s intetizar as evidências disponíveis na literatura científica sobre o uso da auriculoterapia no tratamento da ansiedade em estudantes universitários. Trata-se de uma revisão sistemática da literatura, realizada em 16 bases de dados, com início em 20 de janeiro e revisão até 27 de março de 2021. Todo o processo de busca e seleção dos artigos foi feito de modo independente e pareado, e, quando necessário, um terceiro pesquisador com experiência na temática auxiliava como ad hoc na resolução dos conflitos. O relato da revisão pautou-se na diretriz Preferred Reporting Items for Systematic Reviews and Meta-Analyses, e o protocolo da revisão foi cadastrado na plataforma International Prospective Register of Systematic Reviews (registro No CRD42020205968). Utilizou-se as diretrizes Standards for Reporting Interventions in Clinical Trials of Acupuncture, Cochrane Collaboration Risk of Bias Tool, e escala de JADAD para avaliação dos artigos. A amostra final foi composta por cinco artigos. A análise dos mesmos mostrou que a auriculoterapia contribuiu para tratar a ansiedade de estudantes universitários. O uso desta intervenção deve ser considerado pelas instituições formadoras para promoção da saúde mental nesta população, e pode contribuir para a melhora do desempenho acadêmico, redução das taxas de evasão, e melhora da qualidade de vida aos universitários. O estudo também possibilitou a elaboração de uma tecnologia educativa no formato de cartilha, com o objetivo de esclarecer aos estudantes universitários sobre a ansiedade como um problema de saúde relevante na população, bem como apresentar a auriculoterapia como uma possibilidade terapêutica. Pretende-se que, em momento oportuno, a mesma seja divulgada em formato eletrônico para toda a comunidade acadêmica. Palavras-chave: Auriculoterapia. Terapia auricular. Ansiedade. Estudantes.

scholarly journals When poorly conducted systematic reviews and meta-analyses can mislead: a critical appraisal and update of systematic reviews and meta-analyses examining the effects of probiotics in the treatment of functional constipation in children

2019 ◽  
Vol 110 (1) ◽  
pp. 177-195 ◽  
Author(s):  
Rebecca G Harris ◽  
Elizabeth P Neale ◽  
Isabel Ferreira
Keyword(s):  
Systematic Reviews ◽  
Evidence Synthesis ◽  
Weighted Mean Difference ◽  
Treatment Success ◽  
Functional Constipation ◽  
Risk Of Bias ◽  
Current Evidence ◽  
Success Rates ◽  
Defecation Frequency ◽  
Meta Analyses

ABSTRACT Background Recent systematic reviews and meta-analyses on the efficacy of probiotics in the treatment of functional constipation in children have yielded conflicting results. Objectives The aim of this study was to critically review and update the evidence in this field by mapping all the steps involved against those reported in previous reviews, in an attempt to understand the nature of their conflicting results. Methods Four literature databases, trial registries, and citations were searched through December 1, 2018. We included randomized controlled trials (RCTs) that assessed the effects of probiotics compared with placebo or treatment as usual on defecation frequency [bowel movements (BMs)/wk] or treatment success rates in children with functional constipation. Independent reviewers extracted the data and assessed risk of bias in each RCT. Data were pooled with (inverse variance) random-effects models. Results We identified 17 RCTs, of which 14 and 11 provided sufficient data to enable meta-analysis of the effects of probiotics compared with control on defecation frequency (n = 965) or treatment success (n = 835), respectively. When compared to (any) control intervention, probiotics did not significantly increase defecation frequency [weighted mean difference (WMD): 0.28 BMs/wk; 95% CI: −0.12, 0.69; P = 0.165] but were more efficacious in achieving treatment success (RR: 1.24; 95% CI: 1.03, 1.50; P = 0.024). These effects did not differ by type of control (i.e., active or inactive) intervention. However, in analyses confined to the RCTs that were free of high risk of bias (only 5), probiotics did not confer any beneficial effects on defecation frequency (WMD: −0.55 BMs/wk; 95% CI: −1.37, 0.26; P = 0.185) and achievement of treatment success (RR: 1.01; 95% CI: 0.90, 1.13; P = 0.873), compared with control interventions. Conclusions The current evidence thus does not support the use of probiotics as a single or coadjuvant therapy for treatment of functional constipation in children and refutes recently published reviews reporting favorable effects of probiotics. Conflicting findings of previous reviews resulted from methodologic errors, highlighting the susceptibility of evidence synthesis to oversights in study selection, quality assessments, and data extraction and collation. This review was registered at PROSPERO as CRD42019119109.

scholarly journals COSMOS-E: Guidance on conducting systematic reviews and meta-analyses of observational studies of etiology

PLoS Medicine ◽  
2019 ◽  
Vol 16 (2) ◽  
pp. e1002742 ◽  
Author(s):  
Olaf M. Dekkers ◽  
Jan P. Vandenbroucke ◽  
Myriam Cevallos ◽  
Andrew G. Renehan ◽  
Douglas G. Altman ◽  
...  
Keyword(s):  
Systematic Reviews ◽  
Observational Studies ◽  
Meta Analyses

Is grey literature essential for a better control of publication bias in psychiatry? An example from three meta-analyses of schizophrenia

2005 ◽  
Vol 20 (8) ◽  
pp. 550-553 ◽  
Author(s):  
José Luis R. Martin ◽  
Víctor Pérez ◽  
Montse Sacristán ◽  
Enric Álvarez
Keyword(s):  
Publication Bias ◽  
Systematic Reviews ◽  
Meta Analysis ◽  
Grey Literature ◽  
Risk Of Bias ◽  
Medical Databases ◽  
Study Results ◽  
Heterogeneous Nature ◽  
Meta Analyses ◽  
Literature Material

AbstractSystematic reviews in mental health have become useful tools for health professionals in view of the massive amount and heterogeneous nature of biomedical information available today. In order to determine the risk of bias in the studies evaluated and to avoid bias in generalizing conclusions from the reviews it is therefore important to use a very strict methodology in systematic reviews. One bias which may affect the generalization of results is publication bias, which is determined by the nature and direction of the study results. To control or minimize this type of bias, the authors of systematic reviews undertake comprehensive searches of medical databases and expand on the findings, often undertaking searches of grey literature (material which is not formally published). This paper attempts to show the consequences (and risk) of generalizing the implications of grey literature in the control of publication bias, as was proposed in a recent systematic work. By repeating the analyses for the same outcome from three different systematic reviews that included both published and grey literature our results showed that confusion between grey literature and publication bias may affect the results of a concrete meta-analysis.

scholarly journals Dietary Carbohydrate and Diverse Health Outcomes: Umbrella Review of 30 Systematic Reviews and Meta-Analyses of 281 Observational Studies

2021 ◽  
Vol 8 ◽  
Author(s):  
Ya-Shu Liu ◽  
Qi-Jun Wu ◽  
Jia-Le Lv ◽  
Yu-Ting Jiang ◽  
Hui Sun ◽  
...  
Keyword(s):  
Metabolic Syndrome ◽  
Health Outcomes ◽  
Systematic Reviews ◽  
Observational Studies ◽  
Carbohydrate Intake ◽  
Dietary Carbohydrate ◽  
Umbrella Review ◽  
Suggestive Evidence ◽  
All Cause Mortality ◽  
Meta Analyses

Background and Aims: The associations between dietary carbohydrate and diverse health outcomes remain controversial and confusing. To summarize the existing evidence of the association between dietary carbohydrate intake and diverse health outcomes and to evaluate the credibility of these sources of evidence. We performed this umbrella review of evidence from meta-analyses of observational studies.Methods: PubMed, Embase, Web of Science databases, and manual screening of references up to July 2020 were searched. Systematic reviews with meta-analyses of observational studies in humans investigating the association between dietary carbohydrate intake and multiple health outcomes were identified. We assessed the evidence levels by using summary effect sizes, 95% prediction intervals, between-study heterogeneity, evidence of small-study effects, and evidence of excess significance bias for each meta-analysis.Results: We included 43 meta-analyses of observational research studies with 23 health outcomes, including cancer (n = 26), mortality (n = 4), metabolic diseases (n = 4), digestive system outcomes (n = 3), and other outcomes [coronary heart disease (n = 2), stroke (n = 1), Parkinson's disease (n = 1), and bone fracture (n = 2)]. This umbrella review summarized 281 individual studies with 13,164,365 participants. Highly suggestive evidence of an association between dietary carbohydrate intake and metabolic syndrome was observed with adjusted summary odds ratio of 1.25 [95% confidence interval (CI) 1.15–1.37]. The suggestive evidences were observed in associations of carbohydrate consumption with esophageal adenocarcinoma (0.57, 95% CI = 0.42–0.78) and all-cause mortality (adjusted summary hazard ratio 1.19, 95% CI = 1.09–1.30).Conclusions: Despite the fact that numerous systematic reviews and meta-analyses have explored the relationship between carbohydrate intake and diverse health outcomes, there is no convincing evidence of a clear role of carbohydrate intake. However, there is highly suggestive evidence suggested carbohydrate intake is associated with high risk of metabolic syndrome, suggestive evidence found its association with increased risk of all-cause mortality and decreased risk of esophageal adenocarcinoma.Systematic Review Registration: CRD42020197424.

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