Optimal sample size planning for the Wilcoxon‐Mann‐Whitney test

Happ, Martin; Bathke, Arne C.; Brunner, Edgar

doi:10.1002/sim.7983

Cited by 64 publications

(45 citation statements)

References 29 publications

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“…Using the methodology of optimal sample size planning for the Wilcoxon–Mann–Whitney test, Happ, Bathke, and Brunner (2019) estimated that two data sample sizes ( n 1 = n 2 = 26) are required to achieve at least 80% power. In this study, according to Wilcoxon–Mann–Whitney test, the confidence level of significance of the distributions (Figure 3) varied from 90 to 99% depending on the sample size of the investigated rivers.…”

Section: Resultsmentioning

confidence: 99%

Impact of physico‐geographical factors and climate variability on flow intermittency in the rivers of water surplus zone

Šarauskienė

Akstinas

Nazarenko

et al. 2020

Hydrological Processes

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Climate change is inevitably altering the hydrological regime of water bodies. The interest in changing behaviour of intermittent rivers is increasing in many countries. This research was focused on intermittent rivers (rivers which naturally, periodically cease to flow) in Lithuania. The purpose of this research was to provide an overview of flow intermittency phenomena according to available data in a historical period and to evaluate the impact of catchment geographical features and climate variability on zero‐flow events. The calculated indices of flow intermittency showed that the selected rivers had very different flow regimes. The threshold for the separation of typically intermittent rivers from only occasionally intermittent ones was suggested. Multiple linear regression analysis defined the crucial role of catchment size and watercourse slope on the river cessation process in Lithuania. The applied non‐parametric Wilcoxon–Mann–Whitney test revealed the significance of the relationship between precipitation (in June–September) and zero‐flow duration. Flow intermittency phenomena in Lithuanian rivers were linked to a low‐frequency teleconnection pattern (SCAND index). A methodology of estimating the relation between river intermittency and large‐scale atmospheric circulation pattern (based on SCAND index) was created. The generated regression equations between flow intermittency indices and catchment characteristics might be useful for the estimation of zero‐flows in ungauged river catchments. The main aspect of future investigations might be related to forecasting flow intermittency using modern hydrological models and climate scenarios as well as the defined relationships between zero‐flow indices and physico‐geographical features of river catchments.

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Section: Resultsmentioning

confidence: 99%

Impact of physico‐geographical factors and climate variability on flow intermittency in the rivers of water surplus zone

Šarauskienė

Akstinas

Nazarenko

et al. 2020

Hydrological Processes

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“…The BioPlex system provides a wider dynamic range, greater sensitivity, and more statistical significance for each assay than conventional immunoassays. Hence, in sample size planning the potential for medium to large effect sizes for the differences in the levels of the four cytokines examined and study costs was considered, 17 , 18 as recommended by the FDA study guidelines for estimating minimum appropriate patient sample size and cost. 19 Within the context of testing the hypothesis that there would be significant differences in the levels of each cytokine between OSA patient and airways treated patients and controls, we performed effect size estimates using three methods, (1) the absolute value of r, (2) Cliff’s delta, and (3) Vargha and Delaney’s A.…”

Section: Methodsmentioning

confidence: 99%

Patients with Obstructive Sleep Apnea Have Altered Levels of Four Cytokines Associated with Cardiovascular and Kidney Disease, but Near Normal Levels with Airways Therapy

Wang¹,

Meagher²,

Ambati³

et al. 2021

NSS

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Introduction Obstructive sleep apnea (OSA) results in chronic intermittent hypoxia leading to systemic inflammation, increases in pro-inflammatory cytokines TNF-Alpha and IL-6, and increased risk for a number of life threatening medical disorders such as cardiovascular and kidney disease. Methods A BioPlex Array was used to examined the serum levels of four cytokines also expressed in endothelial cells and/or macrophages and associated with cardiovascular and kidney disease risk. Results Relative to untreated OSA patients, airways treated OSA patients had a 5.4-fold higher median level of MMP2 (p = 9.1x10 −11 ), a 1.4-fold higher level of TWEAK (p = 1.8x10 −7 ), a 1.7-fold higher level of CD163 (p = 1.4x10 −6 ), but a 2.0-fold lower level of MMP3 (p = 7.9x10 −7 ). Airway treatment resulted in levels more similar to or indistinguishable from control subjects. Both t-SNE or UMAP analysis of the global structure of these multi-dimensional data revealed two data clusters, one populated primarily with data for controls and most airways treated OSA patients and a second populated primarily with data for OSA patients. Discussion We discuss a concept in which the aberrant levels of these cytokines in untreated OSA patients may represent a chronic response after years of experiencing intermittent nightly hypoxia, which attenuated the acute response to hypoxia. A balanced therapeutic correction of the aberrant levels of these cytokines may limit the progression of CVD and kidney disease in OSA patients.

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“…The Wilcoxon test was used to compare intra-group differences, and the Mann-Whitney U test was used to compare inter-group differences. (33) We used the SPSS Statistics for Windows, Version 21.0 (IBM Corp., Armonk, NY) to perform statistical analysis and P < 0.05 was considered statistically signi cant.…”

Section: Side Effectsmentioning

confidence: 99%

Comparison of Efficacy and Safety of Duloxetine and Nonsteroidal Anti-inflammatory Drugs in Subacromial Impingement Syndrome

Zhao¹,

Teng²,

Xu³

et al. 2021

Preprint

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Background: Subacromialimpingement syndrome (SIS) is characterized by shoulder pain and restriction in range of motion (ROM), which lead to debility and decrease quality of life (QoL). Duloxetine could provide persistent long-term pain relief in chronic musculoskeletal pain. Therefore, we aimed to investigate the efficacy of duloxetine in stage I or II SIS patients through comparing the nonsteroidal anti-inflammatory drugs (NSAIDs) treatment.Methods: The patients diagnosed with stage I or II SISwere randomly assigned into the duloxetine group (N= 37) and NSAIDs group (N= 37). Duloxetine group patients started on oral duloxetine 40 mg per day for one week and then titrated up to 60 mg per day for one week. NSAIDs group patients received oral loxoprofen sodium tablets 60mg3 times a day for two weeks. The standard measures for investigating the efficacy include pain intensity (VAS), ROM, shoulder functional status, and the QoL at baseline, end of treatment, and at 1 and 3 months follow-up.Results: 74 eligible patients completed the treatment and evaluation. Both treatment groups improved significantly from baseline over time. And all parameters of pain intensity, shoulder functionalstatus and QoL in the duloxetine group were significantly better than those in the NSAIDs group.And no one manifested SIS recurrence and side effects during the entire follow-up period.Conclusions: Both duloxetine and NSAIDs can be beneficial in the rehabilitation of stage I or II SIS patients. Moreover, duloxetine resulted in improvements in outcomes greater than NSAIDs for the treatment of SIS. The current results indicated that duloxetine treatment might be used as a new safe and effective alternative for SIS. Given the encouraging results of this study, it would be worthwhile to confirm our findings in randomized placebo-controlled multicentre clinical trials.

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Optimal sample size planning for the Wilcoxon‐Mann‐Whitney test

Cited by 64 publications

References 29 publications

Impact of physico‐geographical factors and climate variability on flow intermittency in the rivers of water surplus zone

Impact of physico‐geographical factors and climate variability on flow intermittency in the rivers of water surplus zone

Patients with Obstructive Sleep Apnea Have Altered Levels of Four Cytokines Associated with Cardiovascular and Kidney Disease, but Near Normal Levels with Airways Therapy

Comparison of Efficacy and Safety of Duloxetine and Nonsteroidal Anti-inflammatory Drugs in Subacromial Impingement Syndrome

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