Working group

of Ditzhaus

Projects

• Mathematical Complexity Reduction (Research Training Group), Duration 2022-2026, joined as a PI in 2022.
• Modelling and Quantifying effect sizes for survival data in factorial designs - Part II (DFG-Project, DI 2906/1-2), Duration 2022-2025.
• Efficient nonparametric analysis of diagnostic and prognostic biomarkers (DFG-Project, DI 2906/3-1), Duration 2023-2026.

Past projects

• Modelling and Quantifying effect sizes for survival data in factorial designs (DFG-Project, PA 2409/5-1, Duration 2018-2021

R-packages

• mdir.logrank: available on CRAN. This package consists of a flexible combination approach of weighted log-rank-tests for the two-sided (Ditzhaus and Friedrich, 2020) and fone-sided (Ditzhaus and Pauly, 2019) two sample survival testing problem.
• GFD: available on CRAN. Implementation of the QANOVA method (Ditzhaus, Fried and Pauly, 2021, Test) into the existing package GFD consisting of a mean-based procedure for general factorial designs.
• GFDsurv: avaibable on CRAN and as a SHINY-App. This packages contains three different tests for survival data in general factorial designs (Ditzhaus, Dobler and Pauly, 2021; Ditzhaus, Janssen and Pauly, 2020; Dobler and Pauly, SMMR, 2019) from the first project phase. The package will be updated stepwisely by the new methods devoloped during the current second project phase.
• GFDrmst: available on CRAN and as a SHINY-App. This package consists multiple tests based on the restricted mean survival time (RMST) for general factorial designs as described in Munko et al. (2024, Stat. Med.) 
• GFDmcv: available on CRAN. This package consists the global and multiple testing strategies for the multivariate coefficient of variation (Ditzhaus and Smaga, 2022, 2023).

Preprints

• Munko, Ditzhaus, Pauly, Smaga (2024). Multiple Comparison Procedures for Simultaneous Inference in Functional MANOVA. (arXiv:2406.01242)
• Thurow, Dormuth, Sauer, Ditzhaus and Pauly (2023). How to Simulate Realistic Survival Data? A Simulation Study to Compare Realistic Simulation Models.  (arXiv:2308.07842)
• Munko, Ditzhaus, Pauly, Smaga and Zhang (2023). General multiple tests for functional data. (arXiv:2306.15259)
• Fernandez, Rivera and Ditzhaus (2022). A Multiple kernel testing procedure for non-proportional hazards in factorial designs. (arXiv:2206.07239)
• Ditzhaus and Janssen (2019). Dependence correction of multiple tests with applications to sparsity. (arxiv:1909.13727)

Publications

2024

• Ditzhaus and Smaga. Inference for all variants of the multivariate coefficient of variation in factorial designs. Accepted by  Scandinavian Journal of Statistics (preliminary arXiv-preprint, arXiv:2301.12009, is available online.)
• Munko, Ditzhaus, Dobler, Genuneit. RMST-based multiple contrast tests in general factorial designs. Statistics in Medicine; 1-18. doi: 10.1002/sim.10017 (Open Access).
• Baumeister, Ditzhaus and Pauly. Quantile-based MANOVA: A new tool for inferring multivariate data in factorial designs. Journal of Multivariate Analysis 199, 105246. 

2023

• Reimann, Schalk, Jost, Mougiakakos,  Weber,  Döhner,  Recher,  Dumas,  Ditzhaus,  Fischer, Sager. AML consolidation therapy: timing matters. Journal of Cancer Research and Clinical Oncology, DOI: https://doi.org/10.1007/s00432-023-05115-0.
• Matabuena, Félix, Ditzhaus, Vidal and Gude. Hypothesis testing for matched pairs with missing data by maximum mean discrepancy: An application to continuous glucose monitoring.  The American Statistician 77:4, 357-369.
• Emura, Ditzhaus, Dobler, Murotani. Factorial survival analysis for treatment effects under dependent censoring. Statistical Methods in  Medical Research 33(1); 61-79.
• Dormuth, Liu, Xu, Pauly and Ditzhaus. A comparative study to alternatives to the log-rank test. Contemporary Clinical Trials 128;107165.
• Ditzhaus, Yu and Xu. Studentized Permutation Method for Comparing Restricted Mean Survival Times with Small Sample from Randomized Trials. Statistics in Medicine 42;  2226-2240. (Open Access)

2022

• Leyvraz, Konietschke, Peuker, Schütte, Kessler, Ochsenreither, Ditzhaus, Sprünken, Dörpholz, Lamping, Rieke, Klinghammer, Burock, Ulrich, Poch, Schäfer, Klauschen, Joussen, Yaspo, Keilholz. Biomarkers-driven therapies for metastatic uveal melanoma: A prospective precision oncology feasibility study. European Journal of Cancer, DOI: 10.1016/j.ejca.2022.04.004
• Ditzhaus and Gaigall.  Testing marginal homogeneity in Hilbert spaces with applications to stock market returns. TEST 31, 749–770.
• Dormuth, Liu, Xu, Yu, Pauly, Ditzhaus. Which Test for Crossing Survival Curves? A Systematic Review.  BMC Medical Research Methodology 22, Article number: 34 (Open access).
  
• Ditzhaus and Smaga. Permutation test for the multivariate coefficient of variation in factorial designs. Journal of Multivariate Analysis 187, 104848.

2021

• Guckel, Niemann, Ditzhaus, Molatta, Bergau, Fink, Sciacca, El Hamriti, Imnadze, Steinhauer, Braun, Khalaph, Nölker, Sommer, Sohns. Long-term efficacy and impact on Mortality of Remote Magnetic Navigation guided catheter ablation of Ventricular Arrhythmias. Journal of Clinical Medicine 10, 4695.
  
• Ditzhaus, Genuneit, Janssen, Pauly. CASANOVA: Permutation inference in factorial survival designs. Biometrics, early View.
• Lin, Vitkova, Asseyer, Serra, Motamedi, Chien, Ditzhaus, Papadopoulou, Benkert, Kuhle, Bellmann-Strobl, Ruprecht, Paul, Brandt, and Zimmermann. Increased serum neurofilament light and thin ganglion cell-inner plexiform layer are additive risk factors for disease activity in early MS. Neurology: Neuroimmunology & Neuroinflammation 8, e1051.
• Ditzhaus, Fried and Pauly. QANOVA: Quantile-based Permutation Methods For General Factorial Designs. TEST 30, 960–979.
• Ditzhaus, Dobler, Pauly. Inferring median survival differences in general factorial designs via permutation tests. Statistical Methods in Medical Research, 30, 875-891.

2020

• Fernandez, Xu, Ditzhaus and Gretton. A kernel test for quasi-independence. Advances in Neural Information Processing Systems 33.

• Ditzhaus and Friedrich. More powerful logrank permutation tests for two-sample survival data. Journal of Statistical Computation and Simulation 90, 2209-2227.
• Liu*, Ditzhaus* and Xu. A resampling-based test for two crossing survival curves. Pharmaceutical Statistics 19, 399-409 (*equal contribution).

• Ditzhaus and Janssen. Bootstrap and permutation rank tests for proportional hazards under right censoring. Lifetime Data Analysis 26, 493-517.

2019

• Ditzhaus. Signal detection via Phi-divergences for general mixtures. Bernoulli 25, 3041-3068.
• Ditzhaus and Pauly. Wild bootstrap logrank tests with broader power functions for testing superiority. Computational Statistics and Data Analysis, Vol.134, 1-11. 
• Ditzhaus and Janssen. Variability and stability of the false discovery proportion. Electronic Journal of Statistics 13, 882-910.

2018

• Ditzhaus and Janssen. Detectability of nonparametric signals: higher criticism versus likelihood ratio. Electronic Journal of Statistics 12, 4094-4137. 
• Ditzhaus and Gaigall. A consistent goodness-of-fit test in separable Hilbert spaces. Journal of Nonparametric Statistics 30, 834-859.

• Biostatistics
• Factorial Designs
• High or Infinite-Dimensional Statistical Inference, in particular functional data analysis
• Multiple Testing
• Nonparametric Statistics
• Reproducing Kernel Hilbert Spaces
• Resampling Procedures
• Survival Analysis. 

Sommersemester 2024

Survival Analysis E-Learning

Oberseminar zur Stochastik

Wintersemester 2022/23

Wahrscheinlichkeitstheorie LSF E-Learning

Oberseminar zur Stochastik LSF

Sommersemester 2022

Survival Analysis LSF E-Learning

Oberseminar zur Stochastik LSF

Information about my teaching activities before 2022 can be provided on request.

Bachelor, Master, and PhD topics are available upon request, do not hesitate to ask me! Since the majority of topics will naturally come from my research interests, you might check them first and decide what is of your own interest. Furthermore, the following webpage might be useful to choose a general direction of the thesis.

Below, you find a list of theses I supervised in the past.

Supervised Theses in Magdeburg

• Multiple Teststrategien für nichtparametrische Estimands in der Überlebenszeitanalyse (Co-supervision with Prof. Dr. Dennis Dobler, Master thesis, 2024, RUNNING)
• Inference for Competing Risks based on Area between Curves Statisitics  (Co-supervision with Prof. Dr. Markus Pauly, Master thesis, 2024)

Supervised Thesis in Dortmund

• MultiFANOVA: Multiple Contrast Tests for Functional Data (Co-supervision with Prof. Dr. Markus Pauly, Master thesis, 2022) This thesis was awarded by the DStatG as the best master's thesis.
• Random survival forests beyond the Cox model: Simulation study for new splitting rules (Bachelor thesis, 2021)
• Quantile-based MANOVA: A new tool for inferring multivariate data in factorial designs. (Master thesis, 2021)
• Solutions for the curse of non-proportional hazards: The potential of the net benefit in clinical trials (Bachelor thesis, 2021)
• Analysing the Development of IQ in a South African Sample from Childhood to Emerging Adulthood using Latent Class Mixed Models (Bachelor thesis, 2020). This thesis was award by the Alumni Association as the best bachelor thesis.