scholarly journals Adjusting for Publication Bias in JASP — Selection Models and Robust Bayesian Meta-Analysis

2020 ◽  
Author(s):  
František Bartoš ◽  
Maximilian Maier ◽  
Eric-Jan Wagenmakers
Keyword(s):  
Publication Bias ◽  
State Of The Art ◽  
Meta Analysis ◽  
Data Sets ◽  
Selection Models ◽  
The Impact

Meta-analysis is essential for cumulative science, but its validity is compromised by publication bias. In order to mitigate the impact of publication bias, one may apply selection models, which estimate the degree to which non-significant studies are suppressed. Implemented in JASP, these methods allow researchers without programming experience to conduct state-of-the-art publication bias adjusted meta-analysis. In this tutorial, we demonstrate how to conduct a publication bias adjusted meta-analysis in JASP and interpret the results. First, we explain how frequentist selection models correct for publication bias. Second, we introduce Robust Bayesian Meta-Analysis (RoBMA), a Bayesian extension of the frequentist selection models. We illustrate the methodology with two data sets and discuss the interpretation of the results. In addition, we include example text to provide concrete guidance on reporting the meta-analytic results in an academic article. Finally, three tutorial videos are available at https://tinyurl.com/y4g2yodc.

The Three-Cornered Hat Method for Estimating Error Variances of Three or More Atmospheric Data Sets – Part II: Evaluating Radio Occultation and Radiosonde Observations, Global Model Forecasts, and Reanalyses

2021 ◽  
Author(s):  
Therese Rieckh ◽  
Jeremiah P. Sjoberg ◽  
Richard A. Anthes
Keyword(s):  
Radio Occultation ◽  
State Of The Art ◽  
Specific Humidity ◽  
Data Sets ◽  
Error Growth ◽  
Atmospheric Conditions ◽  
Error Statistics ◽  
Weather And Climate ◽  
Atmospheric Data ◽  
The Impact

AbstractWe apply the three-cornered hat (3CH) method to estimate refractivity, bending angle, and specific humidity error variances for a number of data sets widely used in research and/or operations: radiosondes, radio occultation (COSMIC, COSMIC-2), NCEP global forecasts, and nine reanalyses. We use a large number and combinations of data sets to obtain insights into the impact of the error correlations among different data sets that affect 3CH estimates. Error correlations may be caused by actual correlations of errors, representativeness differences, or imperfect co-location of the data sets. We show that the 3CH method discriminates among the data sets and how error statistics of observations compare to state-of-the-art reanalyses and forecasts, as well as reanalyses that do not assimilate satellite data. We explore results for October and November 2006 and 2019 over different latitudinal regions and show error growth of the NCEP forecasts with time. Because of the importance of tropospheric water vapor to weather and climate, we compare error estimates of refractivity for dry and moist atmospheric conditions.

scholarly journals Outlier Detection Based on Residual Histogram Preference for Geometric Multi-Model Fitting

Sensors ◽  
2020 ◽  
Vol 20 (11) ◽  
pp. 3037
Author(s):  
Xi Zhao ◽  
Yun Zhang ◽  
Shoulie Xie ◽  
Qianqing Qin ◽  
Shiqian Wu ◽  
...  
Keyword(s):  
Outlier Detection ◽  
State Of The Art ◽  
Geometric Model ◽  
Model Fitting ◽  
Distribution Model ◽  
Data Sets ◽  
Analysis Method ◽  
Detection Scheme ◽  
The Impact ◽  
Better Than

Geometric model fitting is a fundamental issue in computer vision, and the fitting accuracy is affected by outliers. In order to eliminate the impact of the outliers, the inlier threshold or scale estimator is usually adopted. However, a single inlier threshold cannot satisfy multiple models in the data, and scale estimators with a certain noise distribution model work poorly in geometric model fitting. It can be observed that the residuals of outliers are big for all true models in the data, which makes the consensus of the outliers. Based on this observation, we propose a preference analysis method based on residual histograms to study the outlier consensus for outlier detection in this paper. We have found that the outlier consensus makes the outliers gather away from the inliers on the designed residual histogram preference space, which is quite convenient to separate outliers from inliers through linkage clustering. After the outliers are detected and removed, a linkage clustering with permutation preference is introduced to segment the inliers. In addition, in order to make the linkage clustering process stable and robust, an alternative sampling and clustering framework is proposed in both the outlier detection and inlier segmentation processes. The experimental results also show that the outlier detection scheme based on residual histogram preference can detect most of the outliers in the data sets, and the fitting results are better than most of the state-of-the-art methods in geometric multi-model fitting.

scholarly journals Comparison of Survival Benefits of Combined Chemotherapy and Radiotherapy Versus Chemotherapy Alone for Uterine Serous Carcinoma: A Meta-analysis

2016 ◽  
Vol 27 (1) ◽  
pp. 93-101 ◽  
Author(s):  
Yanying Lin ◽  
Jingyi Zhou ◽  
Yuan Cheng ◽  
Lijun Zhao ◽  
Yuan Yang ◽  
...  
Keyword(s):  
Overall Survival ◽  
Publication Bias ◽  
Meta Analysis ◽  
Serous Carcinoma ◽  
Cochrane Library ◽  
Combined Chemotherapy ◽  
Risk Of Death ◽  
Stage Disease ◽  
Uterine Serous Carcinoma ◽  
The Impact

ObjectiveTo date, there is no convincing evidence comparing the impact of combined chemotherapy and radiotherapy with chemotherapy alone in postoperative uterine serous carcinoma (USC), which remains an unclear issue. We conducted a meta-analysis assessing the impact of combined chemotherapy and radiotherapy compared to chemotherapy alone on overall survival in postoperative USC.MethodsA comprehensive search was performed in the databases of EMBASE, PubMed, Web of Science, and Cochrane Library from inception to March 2016. Studies comparing survival among patients who underwent combined chemotherapy and radiotherapy or chemotherapy alone after surgery for USC were included. Quality assessments were carried out by the Newcastle–Ottawa Scale. Hazard ratio (HR) for overall survival was extracted, and a random-effects model was used for pooled analysis. Publication bias was assessed using both funnel plot and the Egger regression test. Statistical analyses were performed using Stata version 13.0 software.ResultNine retrospective studies with relatively high quality containing 9354 patients were included for the final meta-analysis. The pooled results demonstrated that combined chemotherapy and radiotherapy significantly reduced the risk of death (HR, 0.72; P < 0.0001) compared to chemotherapy alone with a low heterogeneity (I2 = 21.0%, P = 0.256). Subgroup analyses indicated that calculating HR by unadjusted method may cause the heterogeneity among studies. Exploratory analyses showed that either patients with early stage disease (HR, 0.73; P = 0.011) or advanced stage disease (HR, 0.80; P < 0.0001) have survival benefits from combined chemotherapy and radiotherapy. No significant evidence of publication bias was found.ConclusionsThis is the first meta-analysis examining the role of combined chemotherapy and radiotherapy compared to chemotherapy alone in USC. Our results suggest the potential survival benefits of combined chemotherapy and radiotherapy. Further studies, preferably randomized clinical trials, are needed to confirm our results.

The impact of time to adjuvant chemotherapy (AC) on survival in colorectal cancer (CRC): A systematic review and meta-analysis.

2011 ◽  
Vol 29 (4_suppl) ◽  
pp. 364-364 ◽  
Author(s):  
J. J. Biagi ◽  
M. Raphael ◽  
W. D. King ◽  
W. Kong ◽  
W. J. Mackillop ◽  
...  
Keyword(s):  
Systematic Review ◽  
Prognostic Factors ◽  
Adjuvant Chemotherapy ◽  
Publication Bias ◽  
Meta Analysis ◽  
Disease Free Survival ◽  
Significant Heterogeneity ◽  
Risk Of Death ◽  
The Impact ◽  
The Relationship

364 Background: The optimal timing from CRC surgery to initiation of AC is unknown. We report a systematic review and meta-analysis to determine the relationship between time to adjuvant chemotherapy (TTAC) and survival. Methods: A systematic review of literature was done to identify studies that described the relationship between TTAC and survival. Studies were only included if the distribution of relevant prognostic factors was adequately described, and either comparative groups were balanced or results adjusted for the prognostic factors. Hazard ratio (HR) and TTAC for overall survival (OS) and disease free survival (DFS) from each study were converted to a regression coefficient (β) and standard error (SE) corresponding to a continuous representation per 4 weeks of TTAC. The adjusted β from individual studies were combined using a fixed-effect model. Inverse-variance (1/SE2) was used to weight individual studies. The possible effect of publication bias was investigated using the trim and fill approach. Results: We identified 9 eligible studies involving 14,357 patients (4 published articles, 5 abstracts). Two studies were randomized trials and 7 were cohort studies. Six studies reported TTAC as a binary variable and 3 reported TTAC as ≥3 categories. An estimate of HR for OS was derived from all 9 studies and estimate for DFS was derived from 5 studies. Meta-analysis demonstrated that a 4-week increase in TTAC was associated with a significant decrease in both OS (HR = 1.12, 95% CI 1.09-1.15), and DFS (HR = 1.15, 95% CI 1.11-1.20). The analysis showed no significant heterogeneity among studies. These TTAC associations remained significant after analysis for potential publication bias, and when the analysis was repeated excluding the two studies of largest weight. Conclusions: This study demonstrates a 12% increase in the risk of death for each 4 week of delay in the start of AC for CRC. These findings indicate the need for clinicians and health systems managers to take the steps necessary to keep TTAC as short as reasonably achievable. In addition, our results suggest there may be some benefit to AC after a 3-month TTAC delay. No significant financial relationships to disclose.

BDNF Val66Met and clinical response to antipsychotic drugs: A systematic review and meta-analysis

2016 ◽  
Vol 33 (1) ◽  
pp. 45-53 ◽  
Author(s):  
S. Cargnin ◽  
A. Massarotti ◽  
S. Terrazzino
Keyword(s):  
Clinical Response ◽  
Publication Bias ◽  
Antipsychotic Drugs ◽  
Meta Analysis ◽  
Individual Variability ◽  
Sensitivity Analyses ◽  
Significant Heterogeneity ◽  
Relevant Effect ◽  
Quantitative Synthesis ◽  
The Impact

AbstractBackgroundThe polymorphic brain-derived neurotrophic factor (BDNF) gene has been postulated to be involved in inter-individual variability response to antipsychotic drugs.PurposeTo perform a qualitative and quantitative synthesis of studies evaluating the influence of BDNF genetic variation on clinical response to antipsychotics.MethodsThe review protocol was published in the PROSPERO database (Reg. no CRD42015024614). A comprehensive search was performed through PubMed, Web of Knowledge and Cochrane databases up to July 2015. The methodological quality of identified studies was assessed using the MINORS criteria. Publication bias was estimated and potential sources of heterogeneity were investigated via meta-regression, subgroup and sensitivity analyses.ResultsNine studies including a total of 2461 antipsychotic-treated patients fulfilled inclusion criteria for meta-analysis of BDNF Val66Met. Using the random-effects model, the pooled results showed no significant association with antipsychotic response for the dominant (Met carriers vs Val/Val, OR: 0.93, 95% CI: 0.72–1.19, P = 0.55), codominant (Met/Met vs Val/Val, OR: 0.82, 95% CI: 0.59–1.15, P = 0.25), recessive (Met/Met vs Val carriers, OR: 0.81, 95% CI 0.60–1.10, P = 0.18) or the allelic contrast (Met vs Val, OR: 0.92, 95% CI 0.76–1.10, P = 0.34). Visual inspection of funnel plots and further evaluation with Egger's test did not suggest evidence of publication bias. Despite lack of significant heterogeneity in most comparisons, no evidence of association also emerged in the subgroup and sensitivity analyses conducted.ConclusionThe present meta-analysis excludes a clinically relevant effect of BDNF Val66Met on antipsychotic drug response per se. Nevertheless, further investigation is still needed to clarify in well-designed, large sample-based studies, the impact of BDNF haplotypes containing the Val66Met polymorphism.

scholarly journals Long-term outcomes of psychological interventions on children and young people’s mental health: A systematic review and meta-analysis

PLoS ONE ◽  
2020 ◽  
Vol 15 (11) ◽  
pp. e0236525
Author(s):  
Stephen Pilling ◽  
Peter Fonagy ◽  
Elizabeth Allison ◽  
Phoebe Barnett ◽  
Chloe Campbell ◽  
...  
Keyword(s):  
Mental Health ◽  
Systematic Review ◽  
Publication Bias ◽  
Meta Analysis ◽  
Psychosocial Interventions ◽  
Long Term Outcomes ◽  
Self Harm ◽  
The Impact

Background Over 600 RCTs have demonstrated the effectiveness of psychosocial interventions for children and young people’s mental health, but little is known about the long-term outcomes. This systematic review sought to establish whether the effects of selective and indicated interventions were sustained at 12 months. Method We conducted a systematic review and meta-analysis focusing on studies reporting medium term outcomes (12 months after end of intervention). Findings We identified 138 trials with 12-month follow-up data, yielding 165 comparisons, 99 of which also reported outcomes at end of intervention, yielding 117 comparisons. We found evidence of effect relative to control at end of intervention (K = 115, g = 0.39; 95% CI: 0.30–0.47 I2 = 84.19%, N = 13,982) which was maintained at 12 months (K = 165, g = 0.31, CI: 0.25–0.37, I2 = 77.35%, N = 25,652) across a range of diagnostic groups. We explored the impact of potential moderators on outcome, including modality, format and intensity of intervention, selective or indicated intervention, site of delivery, professional/para-professional and fidelity of delivery. We assessed both risk of study bias and publication bias. Conclusions Psychosocial interventions provided in a range of settings by professionals and paraprofessionals can deliver lasting benefits. High levels of heterogeneity, moderate to high risk of bias for most studies and evidence of publication bias require caution in interpreting the results. Lack of studies in diagnostic groups such as ADHD and self-harm limit the conclusions that can be drawn. Programmes that increase such interventions’ availability are justified by the benefits to children and young people and the decreased likelihood of disorder in adulthood.

scholarly journals The Effect of Simulation Technique on Academic Achievement: A Meta-Analysis Study

2020 ◽  
Vol 5 (1) ◽  
pp. 17-36
Author(s):  
Tarik Talan
Keyword(s):  
Academic Achievement ◽  
Publication Bias ◽  
Meta Analysis ◽  
Experimental Studies ◽  
Subject Area ◽  
Simulation Technique ◽  
Bias Analysis ◽  
Analysis Study ◽  
The Mean ◽  
The Impact

This research aims to examine the experimental studies on the impact of simulation technique on students' academic achievement using the meta-analysis method. The previous studies that could be meta-analyzed were examined based on the criteria set out in this study. Finally, 91 studies that were conducted between 2010-2020 years and met the inclusion criteria were subjected to meta-analysis. The sample of the research consisted of 7575 participants. According to the results of the analysis performed using the random-effects model, the mean effect size was calculated as g=0.759 with a standard error of 0.075. Based on the findings, the simulation technique can be said to have a broad impact on students' academic achievement. The results of the publication bias analysis revealed that the present meta-analysis study had no publication bias. On the other hand, the results of the moderator analysis revealed that the impact of the simulation technique on the students' academic achievement did not differ by the teaching levels, course/subject area, and application times, however, it differed by the sample size.

scholarly journals Robust Bayesian Meta-Analysis: Addressing Publication Bias with Model-Averaging

2020 ◽  
Author(s):  
Maximilian Maier ◽  
František Bartoš ◽  
Eric-Jan Wagenmakers
Keyword(s):  
Publication Bias ◽  
Meta Analysis ◽  
Model Misspecification ◽  
Model Averaging ◽  
False Positives ◽  
Selection Models ◽  
Quantitative Tool

Meta-analysis is an important quantitative tool for cumulative science, but its application is frustrated by publication bias. In order to test and adjust for publication bias, we extend model-averaged Bayesian meta-analysis with selection models. The resulting Robust Bayesian Meta-analysis (RoBMA) methodology does not require all-or-none decisions about the presence of publication bias, can quantify evidence in favor of the absence of publication bias, and performs well under high heterogeneity. By model-averaging over a set of 12 models, RoBMA is relatively robust to model misspecification and simulations show that it outperforms existing methods. We demonstrate that RoBMA finds evidence for the absence of publication bias in Registered Replication Reports and reliably avoids false positives. We provide an implementation in R and JASP so that researchers can easily apply the new methodology to their data.

Abstract 14036: Enhanced External Counterpulsation Reduces Blood Pressure in Patients With Chronic Stable Angina: A Meta-Analysis

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Bradley Williams ◽  
Mehak Aggarwal ◽  
Cole Kiser ◽  
Krishnaswami Vijayaraghavan ◽  
Sachin A Shah
Keyword(s):  
Blood Pressure ◽  
Diastolic Blood Pressure ◽  
Publication Bias ◽  
Stable Angina ◽  
Meta Analysis ◽  
Chronic Stable Angina ◽  
External Counterpulsation ◽  
Statistical Heterogeneity ◽  
The Impact ◽  
Enhanced External Counterpulsation

Background: Hypertension is a modifiable risk factor for ASCVD. Enhanced External Counterpulsation (EECP ® ) is an FDA-approved, non-invasive treatment modality for patients with angina and symptoms of ischemic heart failure. Various studies have demonstrated hemodynamic changes with EECP ® therapy, but the true magnitude of benefit remains unknown. We conducted a meta-analysis to assess the change in systolic blood pressure (SBP) and diastolic blood pressure (DBP) post- EECP ® therapy. Methods: A literature search across multiple databases was conducted from its inception to March 2020. Studies evaluating the impact of EECP ® in chronic stable angina patients that reported systolic and diastolic blood pressures were extracted. Human studies published in English, where patients completed 35 hours of EECP ® (administered as 1-hour sessions) were included for analysis. Studies that reported data in multiple arms were treated as individual studies. The weighted mean difference from baseline for SBP and DBP was calculated using the DerSimonian-Laird random-effects model. Statistical heterogeneity was assessed by the I 2 statistic with publication bias evaluated using the Egger bias statistic. Subgroup analyses were performed to assess for clinical heterogeneity. Results: We identified 272 articles, of which 15 unique studies (n=659) reporting data on systolic and diastolic blood pressure were included. Post- EECP ® treatment, SBP decreased by 8.9 mmHg (95% CI 4.0 to 13.7 mmHg, I 2 =87.3%) and DBP reduced by 3.6 mmHg (95% CI 2.1 to 5.0 mmHg, I 2 =38.9%). Patients with a baseline SBP 130 mmHg appear to derive greater benefit (SBP reduced by 13.0 mmHg, 95% CI 8.3 to 17.6, I 2 =70.4%) compared to patients with a baseline SBP<130 (SBP reduced by 3.2 mmHg, 95% CI 0.4 to 6.0, I 2 =25.2). The Egger bias statistic showed no publication bias for the primary endpoints (both p-values>0.33). Conclusion: EECP ® treatment reduced SBP and DBP by over 8 and 3 mmHg respectively. The pleiotropic benefits from EECP ® provide additional hypertension control in patients with chronic stable angina.

scholarly journals A Meta-Analysis of Obesity and Risk of Colorectal Cancer in Patients with Lynch Syndrome: The Impact of Sex and Genetics

Nutrients ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 1736
Author(s):  
Matteo Lazzeroni ◽  
Federica Bellerba ◽  
Mariarosaria Calvello ◽  
Finlay Macrae ◽  
Aung Ko Win ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Lynch Syndrome ◽  
Publication Bias ◽  
Colorectal Neoplasia ◽  
Meta Analysis ◽  
Random Effect ◽  
Normal Weight ◽  
Increased Risk ◽  
Risk Of Cancer ◽  
The Impact

There appears to be a sex-specific association between obesity and colorectal neoplasia in patients with Lynch Syndrome (LS). We meta-analyzed studies reporting on obesity and colorectal cancer (CRC) risk in LS patients to test whether obese subjects were at increased risk of cancer compared to those of normal weight. We explored also a possible sex-specific relationship between adiposity and CRC risk among patients with LS. The summary relative risk (SRR) and 95% confidence intervals (CI) were calculated through random effect models. We investigated the causes of between-study heterogeneity and assessed the presence of publication bias. We were able to retrieve suitable data from four independent studies. We found a twofold risk of CRC in obese men compared to nonobese men (SRR = 2.09; 95%CI: 1.23–3.55, I2 = 33%), and no indication of publication bias (p = 0.13). No significantly increased risk due to obesity was found for women. A 49% increased CRC risk for obesity was found for subjects with an MLH1 mutation (SRR = 1.49; 95%CI: 1.11–1.99, I2 = 0%). These results confirm the different effects of sex on obesity and CRC risk and also support the public measures to reduce overweight in people with LS, particularly for men.

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