Nonparametric MANOVA in meaningful effects

Dobler, Dennis; Friedrich, Sarah; Pauly, Markus

doi:10.1007/s10463-019-00717-3

Cited by 28 publications

(17 citation statements)

References 48 publications

(63 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Most of them control the type-1 error rate accurately with large sample sizes only and, indeed, they show a very liberal or conservative behavior when sample sizes are small. This observation holds for a variety of statistical procedures designed for different questions and fields, including analysis of variance methods 24,37 as well as multiple contrast test procedures using maximum ttest type statistics 38,39 for repeated measures and multivariate data. When the number of comparisons is "small" compared to the sample sizes, approximate and exact methods are available.…”

Section: Discussion and Outlookmentioning

confidence: 86%

Small sample sizes: A big data problem in high-dimensional data analysis

Konietschke

Schwab

Pauly

2020

Stat Methods Med Res

Self Cite

View full text Add to dashboard Cite

In many experiments and especially in translational and preclinical research, sample sizes are (very) small. In addition, data designs are often high dimensional, i.e. more dependent than independent replications of the trial are observed. The present paper discusses the applicability of max t-test-type statistics (multiple contrast tests) in high-dimensional designs (repeated measures or multivariate) with small sample sizes. A randomization-based approach is developed to approximate the distribution of the maximum statistic. Extensive simulation studies confirm that the new method is particularly suitable for analyzing data sets with small sample sizes. A real data set illustrates the application of the methods.

show abstract

Section: Discussion and Outlookmentioning

confidence: 86%

Small sample sizes: A big data problem in high-dimensional data analysis

Konietschke

Schwab

Pauly

2020

Stat Methods Med Res

Self Cite

View full text Add to dashboard Cite

show abstract

“…The details are given in Konietschke et al (2012) and Brunner et al (2017). For multivariate designs, see Dobler et al ., (2020) and Umlauft et al (2019).…”

Section: Explanation Of the Surprising Resultsmentioning

confidence: 97%

“…Acion et al , 2006; Thas et al , 2012), Mann–Whitney & Wilcoxon effect (e.g. Janssen, 1999; Chung & Romano, 2016; Dobler et al , 2020) or stress–strength characteristic (e.g. Kotz et al , 2003).…”

Section: Statistical Model and Notationsmentioning

confidence: 99%

Ranks and Pseudo‐ranks—Surprising Results of Certain Rank Tests in Unbalanced Designs

Brunner

Konietschke

Bathke³

et al. 2020

Int Statistical Rev

Self Cite

View full text Add to dashboard Cite

Summary Rank‐based inference methods are applied in various disciplines, typically when procedures relying on standard normal theory are not justifiable. Various specific rank‐based methods have been developed for two and more samples and also for general factorial designs (e.g. Kruskal–Wallis test or Akritas–Arnold–Brunner test). It is the aim of the present paper (1) to demonstrate that traditional rank procedures for several samples or general factorial designs may lead to surprising results in case of unequal sample sizes as compared with equal sample sizes, (2) to explain why this is the case and (3) to provide a way to overcome these disadvantages. Theoretical investigations show that the surprising results can be explained by considering the non‐centralities of the test statistics, which may be non‐zero for the usual rank‐based procedures in case of unequal sample sizes, while they may be equal to 0 in case of equal sample sizes. A simple solution is to consider unweighted relative effects instead of weighted relative effects. The former effects are estimated by means of the so‐called pseudo‐ranks, while the usual ranks naturally lead to the latter effects. A real data example illustrates the practical meaning of the theoretical discussions.

show abstract

“…Due to the ordinal data level, expression scores were compared by median and interquartile range (IQR), and graphical representation was done by boxplots and scatterplots. Expression levels were compared in multivariate models per intestinal section by the nonparametric method of Dobler et al, including disease (CD, UC) vs. controls, age (pediatric vs. adults), and the interaction in all models [ 28 ]. p values of these three models were corrected using the Bonferroni method.…”

Section: Methodsmentioning

confidence: 99%

Expression of Oxidative Phosphorylation Complexes and Mitochondrial Mass in Pediatric and Adult Inflammatory Bowel Disease

Schneider

Özsoy

Zimmermann

et al. 2022

Oxidative Medicine and Cellular Longevity

View full text Add to dashboard Cite

Introduction. Inflammatory bowel disease (IBD), which includes Crohn’s disease (CD) and ulcerative colitis (UC), is a multifactorial intestinal disorder but its precise etiology remains elusive. As the cells of the intestinal mucosa have high energy demands, mitochondria may play a role in IBD pathogenesis. The present study is aimed at evaluating the expression levels of mitochondrial oxidative phosphorylation (OXPHOS) complexes in IBD. Material and Methods. 286 intestinal biopsy samples from the terminal ileum, ascending colon, and rectum from 124 probands (34 CD, 33 UC, and 57 controls) were stained immunohistochemically for all five OXPHOS complexes and the voltage-dependent anion-selective channel 1 protein (VDAC1 or porin). Expression levels were compared in multivariate models including disease stage (CD and UC compared to controls) and age (pediatric/adult). Results. Analysis of the terminal ileum of CD patients revealed a significant reduction of complex II compared to controls, and a trend to lower levels was evident for VDAC1 and the other OXPHOS complexes except complex III. A similar pattern was found in the rectum of UC patients: VDAC1, complex I, complex II, and complex IV were all significantly reduced, and complex III and V showed a trend to lower levels. Reductions were more prominent in older patients compared to pediatric patients and more marked in UC than CD. Conclusion. A reduced mitochondrial mass is present in UC and CD compared to controls. This is potentially a result of alterations of mitochondrial biogenesis or mitophagy. Reductions were more pronounced in older patients compared to pediatric patients, and more prominent in UC than CD. Complex I and II are more severely compromised than the other OXPHOS complexes. This has potential therapeutic implications, since treatments boosting biogenesis or influencing mitophagy could be beneficial for IBD treatment. Additionally, substances specifically stimulating complex I activity should be tested in IBD treatment.

show abstract

Nonparametric MANOVA in meaningful effects

Cited by 28 publications

References 48 publications

Small sample sizes: A big data problem in high-dimensional data analysis

Small sample sizes: A big data problem in high-dimensional data analysis

Ranks and Pseudo‐ranks—Surprising Results of Certain Rank Tests in Unbalanced Designs

Expression of Oxidative Phosphorylation Complexes and Mitochondrial Mass in Pediatric and Adult Inflammatory Bowel Disease

Contact Info

Product

Resources

About