scholarly journals Multiple testing of pairwise comparisons

2010 ◽  
pp. 144-157 ◽  
Author(s):  
Arthur Cohen ◽  
Harold Sackrowitz ◽  
Chuanwen Chen
Keyword(s):  
Multiple Testing ◽  
Pairwise Comparisons

scholarly journals Not so different in present attitudes and behaviour, but expected future membership: A technical replication of a study of party youth in six European democracies

2018 ◽  
Vol 5 (1) ◽  
pp. 205316801876487
Author(s):  
Lion Behrens ◽  
Ingo Rohlfing
Keyword(s):  
Multiple Testing ◽  
Type I Error ◽  
Statistical Significance ◽  
Original Study ◽  
Pairwise Comparisons ◽  
Type I ◽  
Significance Tests ◽  
Party Members ◽  
Original Survey ◽  
Technical Replication

Based on the statistical analysis of an original survey of young party members from six European democracies, a study concluded that three types of young members differed systematically regarding their membership objectives, activism, efficacy and perceptions of the party and self-perceived political future. We performed a technical replication of the original study, correcting four deficiencies, which led us to a different conclusion. First, we discuss substantive significance in addition to statistical significance. Second, we ran significance tests on all comparisons instead of limiting them to an arbitrary subset. Third, we performed pairwise comparisons between the three types of members instead of using pooled groups. Fourth, we avoided the inflation of the type-I error rate due to multiple testing by using the Bonferroni–Holm correction. We found that most of the differences between the types lacked substantive significance, and that statistical significance only coherently distinguished the types of members in their future membership, but not in their present behaviour and attitudes.

scholarly journals Hippocampal subfield volumes are uniquely affected in PTSD and depression: International analysis of 31 cohorts from the PGC-ENIGMA PTSD Working Group

2019 ◽  
Author(s):  
Lauren E. Salminen ◽  
Philipp G. Sämann ◽  
Yuanchao Zheng ◽  
Emily L. Dennis ◽  
Emily K. Clarke-Rubright ◽  
...  
Keyword(s):  
Childhood Trauma ◽  
Multiple Testing ◽  
Alcohol Use Disorder ◽  
Pairwise Comparisons ◽  
Compelling Evidence ◽  
Sex Effects ◽  
Main Effect ◽  
Secondary Analyses ◽  
Current Ptsd

AbstractBackgroundPTSD and depression commonly co-occur and have been associated with smaller hippocampal volumes compared to healthy and trauma-exposed controls. However, the hippocampus is heterogeneous, with subregions that may be uniquely affected in individuals with PTSD and depression.MethodsWe used random effects regressions and a harmonized neuroimaging protocol based on FreeSurfer (v6.0) to identify sub-structural hippocampal markers of current PTSD (C-PTSD), depression, and the interaction of these conditions across 31 cohorts worldwide (N=3,115; Mage=38.9±13.9 years). Secondary analyses tested these associations by sex and after modeling the simultaneous effects of remitted PTSD, childhood trauma, mild traumatic brain injury, and alcohol use disorder.ResultsA significant negative main effect of depression (n=800, vs. no depression, n=1456) was observed in the hippocampal tail (ß=−0.13) and CA1 (ß=−0.09) after adjusting for covariates and multiple testing (adjusted p’s (q)=0.028). A main effect of C-PTSD (n=1042 vs. control, n=1359) was not significant, but an interaction between C-PTSD and depression was significant in the CA1 (ß=−0.24, q=0.044). Pairwise comparisons revealed significantly smaller CA1 volumes in individuals with C-PTSD+Depression than controls (ß=−0.12, q=0.012), C-PTSD-only (ß=−0.17, q=0.001), and Depression-only (ß=−0.18, q=0.023). Follow-up analyses revealed sex effects in the hippocampal tail of depressed females, and an interaction effect of C-PTSD and depression in the fimbria of males.ConclusionsCollectively our results suggest that depression is a stronger predictor of hippocampal volumetry than PTSD, particularly in the CA1, and provide compelling evidence of more pronounced hippocampal phenotypes in comorbid PTSD and depression compared to either condition alone.

scholarly journals A Bayesian Approach to the Correction for Multiplicity

2019 ◽  
Author(s):  
Tim de Jong
Keyword(s):  
Bayesian Methods ◽  
Multiple Testing ◽  
Correction Method ◽  
The Other ◽  
Dependence Structure ◽  
Pairwise Comparisons ◽  
Multiple Hypothesis ◽  
Positive Results ◽  
One Way Anova ◽  
Do So

There are many situations in which researchers perform multiple hypothesis tests simultaneously. It is important that the results of these tests are corrected for multiplicity. If this correction is not performed, it is likely that some null hypotheses will be falsely rejected. There are various different methods for performing multiplicity corrections, dependent on the specific type of multiple testing. If you find yourself in the frequentist camp and wish to conduct pairwise comparisons following a one-way ANOVA you are in luck, as methods to do so are readily available to researchers. On the other hand, a Bayesian is hard-pressed to find an appropriate correction method in this case. In this thesis we evaluate two Bayesian methods that allow pairwise comparisons while protecting against false positive results. We demonstrate the importance of dealing with the dependence structure that exists among pairwise comparisons. To aid researchers with their statistical inference our aim is to implement these methods in the statisticssoftware JASP.

Heteroscedastic Methods for Performing All Pairwise Comparisons of Regression Lines Associated With J Independent Groups

Methodology ◽  
2015 ◽  
Vol 11 (3) ◽  
pp. 110-115 ◽  
Author(s):  
Rand R. Wilcox ◽  
Jinxia Ma
Keyword(s):  
Least Squares ◽  
Pairwise Comparisons ◽  
Simple Extension ◽  
Type I ◽  
Type I Errors ◽  
Well Elderly ◽  
Using Data

Abstract. The paper compares methods that allow both within group and between group heteroscedasticity when performing all pairwise comparisons of the least squares lines associated with J independent groups. The methods are based on simple extension of results derived by Johansen (1980) and Welch (1938) in conjunction with the HC3 and HC4 estimators. The probability of one or more Type I errors is controlled using the improvement on the Bonferroni method derived by Hochberg (1988) . Results are illustrated using data from the Well Elderly 2 study, which motivated this paper.

scholarly journals Genetic biomarkers in the VEGF pathway predicting response to anti-VEGF therapy in age-related macular degeneration

2019 ◽  
Vol 4 (1) ◽  
pp. e000273
Author(s):  
Irina Balikova ◽  
Laurence Postelmans ◽  
Brigitte Pasteels ◽  
Pascale Coquelet ◽  
Janet Catherine ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Macular Degeneration ◽  
Treatment Response ◽  
Multiple Testing ◽  
Age Related Macular Degeneration ◽  
Patient Specific ◽  
Multiple Testing Correction ◽  
Anti Vegf ◽  
Age Related ◽  
Vegf Pathway

ObjectiveAge-related macular degeneration (ARMD) is a leading cause of visual impairment. Intravitreal injections of anti-vascular endothelial growth factor (VEGF) are the standard treatment for wet ARMD. There is however, variability in patient responses, suggesting patient-specific factors influencing drug efficacy. We tested whether single nucleotide polymorphisms (SNPs) in genes encoding VEGF pathway members contribute to therapy response.Methods and analysisA retrospective cohort of 281 European wet ARMD patients treated with anti-VEGF was genotyped for 138 tagging SNPs in the VEGF pathway. Per patient, we collected best corrected visual acuity at baseline, after three loading injections and at 12 months. We also registered the injection number and changes in retinal morphology after three loading injections (central foveal thickness (CFT), intraretinal cysts and serous neuroepithelium detachment). Changes in CFT after 3 months were our primary outcome measure. Association of SNPs to response was assessed by binomial logistic regression. Replication was attempted by associating visual acuity changes to genotypes in an independent Japanese cohort.ResultsAssociation with treatment response was detected for seven SNPs, including in FLT4 (rs55667289: OR=0.746, 95% CI 0.63 to 0.88, p=0.0005) and KDR (rs7691507: OR=1.056, 95% CI 1.02 to 1.10, p=0.005; and rs2305945: OR=0.963, 95% CI 0.93 to 1.00, p=0.0472). Only association with rs55667289 in FLT4 survived multiple testing correction. This SNP was unavailable for testing in the replication cohort. Of six SNPs tested for replication, one was significant although not after multiple testing correction.ConclusionIdentifying genetic variants that define treatment response can help to develop individualised therapeutic approaches for wet ARMD patients and may point towards new targets in non-responders.

scholarly journals Multitrait genetic association analysis identifies 50 new risk loci for gastro-oesophageal reflux, seven new loci for Barrett’s oesophagus and provides insights into clinical heterogeneity in reflux diagnosis

Gut ◽  
2021 ◽  
pp. gutjnl-2020-323906
Author(s):  
Jue-Sheng Ong ◽  
Jiyuan An ◽  
Xikun Han ◽  
Matthew H Law ◽  
Priyanka Nandakumar ◽  
...  
Keyword(s):  
Risk Factors ◽  
Multiple Testing ◽  
Association Studies ◽  
Barrett’S Oesophagus ◽  
Oesophageal Reflux ◽  
Oesophageal Adenocarcinoma ◽  
Specific Gene ◽  
Genome Wide Association Studies ◽  
Disease Heterogeneity ◽  
Barrett's Oesophagus

ObjectiveGastro-oesophageal reflux disease (GERD) has heterogeneous aetiology primarily attributable to its symptom-based definitions. GERD genome-wide association studies (GWASs) have shown strong genetic overlaps with established risk factors such as obesity and depression. We hypothesised that the shared genetic architecture between GERD and these risk factors can be leveraged to (1) identify new GERD and Barrett’s oesophagus (BE) risk loci and (2) explore potentially heterogeneous pathways leading to GERD and oesophageal complications.DesignWe applied multitrait GWAS models combining GERD (78 707 cases; 288 734 controls) and genetically correlated traits including education attainment, depression and body mass index. We also used multitrait analysis to identify BE risk loci. Top hits were replicated in 23andMe (462 753 GERD cases, 24 099 BE cases, 1 484 025 controls). We additionally dissected the GERD loci into obesity-driven and depression-driven subgroups. These subgroups were investigated to determine how they relate to tissue-specific gene expression and to risk of serious oesophageal disease (BE and/or oesophageal adenocarcinoma, EA).ResultsWe identified 88 loci associated with GERD, with 59 replicating in 23andMe after multiple testing corrections. Our BE analysis identified seven novel loci. Additionally we showed that only the obesity-driven GERD loci (but not the depression-driven loci) were associated with genes enriched in oesophageal tissues and successfully predicted BE/EA.ConclusionOur multitrait model identified many novel risk loci for GERD and BE. We present strong evidence for a genetic underpinning of disease heterogeneity in GERD and show that GERD loci associated with depressive symptoms are not strong predictors of BE/EA relative to obesity-driven GERD loci.

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