An Umbrella Review of Effect Size, Bias and Power Across Meta‐Analyses in Emergency Medicine

2021 ◽  
Author(s):  
Austin J. Parish ◽  
Denley M.K. Yuan ◽  
Jason R. Raggi ◽  
Oluyemi O. Omotoso ◽  
Jason R. West ◽  
...  
Keyword(s):  
Emergency Medicine ◽  
Effect Size ◽  
Umbrella Review ◽  
Size Bias ◽  
Meta Analyses

scholarly journals Effects of diet on obesity-related anthropometric characteristics in adults: a protocol for an umbrella review of meta-analyses of randomised controlled trials

BMJ Open ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. e050579
Author(s):  
Shunlian Fu ◽  
Qian Zhou ◽  
Lijun Yuan ◽  
Zinan Li ◽  
Qiu Chen
Keyword(s):  
Effect Size ◽  
Randomised Controlled Trials ◽  
Meta Analysis ◽  
Measurement Tool ◽  
Controlled Trials ◽  
Umbrella Review ◽  
Effect Model ◽  
Anthropometric Characteristics ◽  
Randomised Controlled ◽  
Meta Analyses

IntroductionThere have been many meta-analyses of randomised controlled trials on the influence of different diets on obesity-related anthropometric characteristics in adults. However, whether diet interventions can effectively decrease obesity-related anthropometric characteristics remains unclear. The objective of this study is to summarise and synthesise the evidence on the effects of diet on obesity-related anthropometric characteristics in adults by an umbrella review of meta-analyses of randomised controlled trials.Methods and analysisWe will first retrieve English articles only published before 15 December 2021 by searching PubMed, Embase and Web of Science. Only articles that are meta-analyses of randomised controlled trials will be included. Three researchers will independently screen the titles and abstracts of retrieved articles and check the data extracted from each eligible meta-analysis. In each meta-analysis, we will consider calculating the effect size of the mean difference of the effect of each diet on obesity-related anthropometric characteristics in adults using a random-effect model or a fixed-effect model according to heterogeneity. Study heterogeneity (Cochrane’s Q and I2 statistics) and small-study effects (Egger’s test or Begg’s test) will be considered. Evidence of each effect size will be graded according to the NutriGrade scoring system. We will use AMSTAR-2 (A Measurement Tool to Assess Systematic Reviews V.2) to assess the methodological quality of each meta-analysis.Ethics and disseminationThis umbrella review will provide information on the effects of different diets on obesity-related anthropometric characteristics in adults. Ethical approval is not necessary for this study. We will publish the completed umbrella review and related data online.PROSPERO registration numberCRD42021232826.

How to Detect Publication Bias in Psychological Research

2019 ◽  
Vol 227 (4) ◽  
pp. 261-279 ◽  
Author(s):  
Frank Renkewitz ◽  
Melanie Keiner
Keyword(s):  
Publication Bias ◽  
Effect Size ◽  
Statistical Power ◽  
Type I Error ◽  
Psychological Research ◽  
Type I ◽  
True Effect Size ◽  
Questionable Research Practices ◽  
True Effect ◽  
Meta Analyses

Abstract. Publication biases and questionable research practices are assumed to be two of the main causes of low replication rates. Both of these problems lead to severely inflated effect size estimates in meta-analyses. Methodologists have proposed a number of statistical tools to detect such bias in meta-analytic results. We present an evaluation of the performance of six of these tools. To assess the Type I error rate and the statistical power of these methods, we simulated a large variety of literatures that differed with regard to true effect size, heterogeneity, number of available primary studies, and sample sizes of these primary studies; furthermore, simulated studies were subjected to different degrees of publication bias. Our results show that across all simulated conditions, no method consistently outperformed the others. Additionally, all methods performed poorly when true effect sizes were heterogeneous or primary studies had a small chance of being published, irrespective of their results. This suggests that in many actual meta-analyses in psychology, bias will remain undiscovered no matter which detection method is used.

scholarly journals Virtual Reality in Neurorehabilitation: An Umbrella Review of Meta-Analyses

2021 ◽  
Vol 10 (7) ◽  
pp. 1478
Author(s):  
Alexandra Voinescu ◽  
Jie Sui ◽  
Danaë Stanton Fraser
Keyword(s):  
Virtual Reality ◽  
Cerebral Palsy ◽  
Brain Injury ◽  
Upper Limb ◽  
Umbrella Review ◽  
High Quality ◽  
Quality Of Evidence ◽  
Upper Limb Function ◽  
Meta Analyses

Neurological disorders are a leading cause of death and disability worldwide. Can virtual reality (VR) based intervention, a novel technology-driven change of paradigm in rehabilitation, reduce impairments, activity limitations, and participation restrictions? This question is directly addressed here for the first time using an umbrella review that assessed the effectiveness and quality of evidence of VR interventions in the physical and cognitive rehabilitation of patients with stroke, traumatic brain injury and cerebral palsy, identified factors that can enhance rehabilitation outcomes and addressed safety concerns. Forty-one meta-analyses were included. The data synthesis found mostly low- or very low-quality evidence that supports the effectiveness of VR interventions. Only a limited number of comparisons were rated as having moderate and high quality of evidence, but overall, results highlight potential benefits of VR for improving the ambulation function of children with cerebral palsy, mobility, balance, upper limb function, and body structure/function and activity of people with stroke, and upper limb function of people with acquired brain injury. Customization of VR systems is one important factor linked with improved outcomes. Most studies do not address safety concerns, as only nine reviews reported adverse effects. The results provide critical recommendations for the design and implementation of future VR programs, trials and systematic reviews, including the need for high quality randomized controlled trials to test principles and mechanisms, in primary studies and in meta-analyses, in order to formulate evidence-based guidelines for designing VR-based rehabilitation interventions.

scholarly journals Efficacy and safety of aliskiren combination therapy: a protocol for an umbrella review

BMJ Open ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. e043807
Author(s):  
Jiantong Shen ◽  
Wenming Feng ◽  
Yike Wang ◽  
Qiyuan Zhao ◽  
Billong Laura Flavorta ◽  
...  
Keyword(s):  
Combination Therapy ◽  
Systematic Reviews ◽  
Cochrane Library ◽  
Umbrella Review ◽  
Quality Of Reporting ◽  
Ethical Approval ◽  
Registration Number ◽  
Third Person ◽  
Meta Analyses ◽  
The Impact

IntroductionEfficacy of aliskiren combination therapy with other antihypertensive has been evaluated in the treatment of patients with hypertension in recent systematic reviews. However, most previous reviews only focused on one single health outcome or one setting, none of them made a full summary that assessed the impact of aliskiren combination treatment comprehensively. As such, this umbrella review based on systematic reviews and meta-analyses is aimed to synthesise the evidences on efficacy, safety and tolerability of aliskiren-based therapy for hypertension and related comorbid patients.Methods and analysisA comprehensive search of PubMed, EMBASE, Cochrane Library, CNKI published from inception to August 2020 will be conducted. The selected articles are systematic reviews which evaluated efficacy, safety and tolerability of aliskiren combination therapy. Two reviewers will screen eligible articles, extract data and evaluate quality independently. Any disputes will be resolved by discussion or the arbitration of a third person. The quality of reporting evidence will be assessed using the Assessment of Multiple Systematic Reviews V.2 tool tool. We will take a mixed-methods approach to synthesising the review literatures, reporting summary of findings tables and iteratively mapping the results.Ethics and disseminationEthical approval is not required for the study, as we would only collect data from available published materials. This umbrella review will be also submitted to a peer-reviewed journal for publication after completion.PROSPERO registration numberCRD42020192131.

scholarly journals Frailty Status and All-Cause Mortality in the Community-Dwelling Older People: An Umbrella Review

2020 ◽  
Vol 4 (Supplement_1) ◽  
pp. 488-489
Author(s):  
A R M Saifuddin Ekram ◽  
Joanne Ryan ◽  
Carlene Britt ◽  
Sara Espinoza ◽  
Robyn Woods
Keyword(s):  
Older People ◽  
Systematic Reviews ◽  
Community Dwelling ◽  
Umbrella Review ◽  
Frailty Phenotype ◽  
Frailty Status ◽  
Increased Risk ◽  
All Cause Mortality ◽  
Community Dwelling Older People ◽  
Meta Analyses

Abstract Frailty is increasingly recognised for its association with adverse health outcomes including mortality. However, various measures are used to assess frailty, and the strength of association could vary depending on the specific definition used. This umbrella review aimed to map which frailty scale could best predict the relationship between frailty and all-cause mortality among community-dwelling older people. According to the PRISMA guidelines, Medline, Embase, EBSCOhost and Web of Science databases were searched to identify eligible systematic reviews and meta-analyses which examined the association between frailty and all-cause mortality in the community-dwelling older people. Relevant data were extracted and summarised qualitatively. Methodological quality was assessed by AMSTAR-2 checklist. Five moderate-quality systematic reviews with a total of 374,529 participants were identified. Of these, two examined the frailty phenotype and its derivatives, two examined the cumulative deficit models and the other predominantly included studies assessing frailty with the FRAIL scale. All of the reviews found a significant association between frailty status and all-cause mortality. The magnitude of association varied between individual studies, with no consistent pattern related to the frailty measures that were used. In conclusion, regardless of the measure used to assess frailty status, it is associated with an increased risk of all-cause mortality.

scholarly journals Predictability of rotational tooth movement with orthodontic aligners comparing software-based and achieved data: A systematic review and meta-analysis of observational studies

2021 ◽  
pp. 146531252110272
Author(s):  
Despina Koletsi ◽  
Anna Iliadi ◽  
Theodore Eliades
Keyword(s):  
Effect Size ◽  
Tooth Movement ◽  
Data Extraction ◽  
Meta Analysis ◽  
Risk Of Bias ◽  
Patient Treatment ◽  
Qualitative Synthesis ◽  
Meta Analyses ◽  
Enamel Reduction

Objective: To evaluate all available evidence on the prediction of rotational tooth movements with aligners. Data sources: Seven databases of published and unpublished literature were searched up to 4 August 2020 for eligible studies. Data selection: Studies were deemed eligible if they included evaluation of rotational tooth movement with any type of aligner, through the comparison of software-based and actually achieved data after patient treatment. Data extraction and data synthesis: Data extraction was done independently and in duplicate and risk of bias assessment was performed with the use of the QUADAS-2 tool. Random effects meta-analyses with effect sizes and their 95% confidence intervals (CIs) were performed and the quality of the evidence was assessed through GRADE. Results: Seven articles were included in the qualitative synthesis, of which three contributed to meta-analyses. Overall results revealed a non-accurate prediction of the outcome for the software-based data, irrespective of the use of attachments or interproximal enamel reduction (IPR). Maxillary canines demonstrated the lowest percentage accuracy for rotational tooth movement (three studies: effect size = 47.9%; 95% CI = 27.2–69.5; P < 0.001), although high levels of heterogeneity were identified (I2: 86.9%; P < 0.001). Contrary, mandibular incisors presented the highest percentage accuracy for predicted rotational movement (two studies: effect size = 70.7%; 95% CI = 58.9–82.5; P < 0.001; I2: 0.0%; P = 0.48). Risk of bias was unclear to low overall, while quality of the evidence ranged from low to moderate. Conclusion: Allowing for all identified caveats, prediction of rotational tooth movements with aligner treatment does not appear accurate, especially for canines. Careful selection of patients and malocclusions for aligner treatment decisions remain challenging.

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