Search results for "Publication Bias"
showing 10 items of 42 documents
Meta-Analysis in Epidemiology
2007
The use of meta-analyses in order to synthesise the evidence from epidemiological studies has become more and more popular recently. It has been estimated by Egger et al. (1998) that from articles retrieved by MEDLINE with the medical subject heading (MeSH) term “meta-analysis” some 33% reported results of a meta-analysis from randomised clinical trials and nearly the same proportion (27%) were from observational studies, including 12% papers in which the aetiology of a disease was investigated. The remaining papers include methodological publications or review articles. Reasons for the popularity of meta-analyses are the growing information in the scientific literature and the need of time…
Biases in study design, implementation, and data analysis that distort the appraisal of clinical benefit and ESMO-Magnitude of Clinical Benefit Scale…
2021
BACKGROUND: The European Society for Medical Oncology-Magnitude of Clinical Benefit Scale (ESMO-MCBS) is a validated, widely used tool developed to score the clinical benefit from cancer medicines reported in clinical trials. ESMO-MCBS scores assume valid research methodologies and quality trial implementation. Studies incorporating flawed design, implementation, or data analysis may generate outcomes that exaggerate true benefit and are not generalisable. Failure to either indicate or penalise studies with bias undermines the intention and diminishes the integrity of ESMO-MCBS scores. This review aimed to evaluate the adequacy of the ESMO-MCBS to address bias generated by flawed design, im…
The short-term efficacy and safety of artificial total disc replacement for selected patients with lumbar degenerative disc disease compared with ant…
2018
PurposeTo systematically compare the efficacy and safety of lumbar total disc replacement (TDR) with the efficacy and safety of anterior lumbar interbody fusion (ALIF) for the treatment of lumbar degenerative disc disease (LDDD).MethodsThe electronic databases PubMed, Web of Science and the Cochrane Library were searched for the period from the establishment of the databases to March 2018. The peer-reviewed articles that investigate the safety and efficacy of TDR and ALIF were retrieved under the given search terms. Quality assessment must be done independently by two authors according to each item of criterion. The statistical analyses were performed using RevMan (version 5.3) and Stata (v…
Heart rate variability and self-control—A meta-analysis
2015
Heart rate variability (HRV) has been suggested as a biological correlate of self-control. Whereas many studies found a relationship between HRV at rest and self-control, effect sizes vary substantially across studies in magnitude and direction. This meta-analysis evaluated the association between HRV at rest and self-control in laboratory tasks, with a particular focus on the identification of moderating factors (task characteristics, methodological aspects of HRV assessment, demographics). Overall, 24 articles with 26 studies and 132 effects (n=2317, mean age=22.44, range 18.4-57.8) were integrated (random effects model with robust variance estimation). We found a positive average effect …
‘You play like a Woman!’ Effects of gender stereotype threat on Women's performance in physical and sport activities: A meta-analysis
2018
Abstract Objectives The purpose of this quantitative review was to provide an estimation of the effect of stereotype threat on women's performance in sport. Design This review employed a meta-analytic technique. Method a meta-analysis with random effects model was performed on 24 effects. Publication bias was tested through funnel plots and Egger's regression test. Results Findings show a symmetric distribution of effects, making it possible to conclude that no file-drawer problem affected the collected sample of effects. Aggregating the results of the reviewed studies, a medium effect of stereotype threat manipulation on women's sport performances emerged (d = 0.33). Collected studies were…
Sex differences in the prevalence of Helicobacter pylori infection: an individual participant data pooled analysis (StoP Project)
2019
Background Helicobacter pylori (H. pylori) infection is more frequent among men, though the magnitude of the association might be inaccurate due to potential misclassification of lifetime infection and publication bias. Moreover, infection is common, and most studies are cross-sectional. Thus, prevalence ratios (PRs) may be easier to interpret than odds ratios (ORs). Aim The aim of this study was to quantify the association between sex and H. pylori infection using controls from 14 studies from the Stomach Cancer Pooling (StoP) Project. Participants and methods H. pylori infection was defined based on IgG serum antibody titers or multiplex serology. Participants were also classified as infe…
Relationship between depression and frailty in older adults: A systematic review and meta-analysis
2017
Aim Depression and frailty are prevalent and burdensome in older age. However, the relationships between these entities are unclear and no quantitative meta- analysis exists. We conducted a systematic review and meta-analysis to investigate the associations between depression and frailty. Methods Two authors searched major electronic databases from inception until November-2016 for cross-sectional/longitudinal studies investigating depression and frailty. The strength of the reciprocal associations between frailty and depression was assessed through odds ratios (ORs) adjusted for potential confounders. Results From 2306 non duplicated hits, 24 studies were included. The overall prevalence o…
Avoiding Bias in Observational Studies
2009
Background Many questions in human health research can only be answered with observational studies. In contrast to controlled experiments or well-planned, experimental randomized clinical trials, observational studies are subject to a number of potential problems that may bias their results.
Un análisis empírico del impacto de la regulación contable en el mercado de auditoría
2017
El objetivo de la presente tesis se centra en el estudio de la estructura del mercado de la auditoría así como en analizar el impacto económico que la regulación contable ejerce sobre determinados elementos del mercado de auditoría (honorarios y rentabilidad de las firmas de auditoría). A partir de la publicación del Reglamento europeo 1606/2002 se requirió a los grupos cotizados que formulasen sus estados financieros consolidados desde el 1 de enero de 2005, conforme a las Normas Internacionales de Información Financiera o NIIF. En España, la adaptación de las NIIF al resto de empresas, no se llevó a cabo hasta la aprobación del Nuevo Plan General Contable (NPGC) y del plan para pequeñas y…
Effect of pistachio on brachial artery diameter and flow-mediated dilatation: A systematic review and meta-analysis of randomized, controlled-feeding…
2017
Background: Results of previous clinical trials evaluating the effect of pistachio supplementation on endothelial reactivity (ER) are controversial. Aims: We aimed to assess the impact of pistachio on ER through systematic review of literature and meta-analysis of available randomized, controlled-feeding clinical studies (RCTs). Methods: The literature search included SCOPUS, PubMed-Medline, ISI Web of Science and Google Scholar databases up to 1st August 2017 to identify RCTs investigating the impact of pistachio on ER. Two independent reviewers extracted data on study characteristics, methods and outcomes. Overall, the impact of pistachio on ER was reported in 4 trials. Results: The meta-…