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Dr. Sam Doerken


Photo - Sam Doerken 
Phone: ++49 (0)761 203-7703
Fax: ++49 (0)761 203-7700
FDM, Ernst-Zermelo-Str. 1
Room no.: 106

Research Interests

  • Healthcare-associated infections
  • Point prevalence studies
  • Penalized regression
  • Sparse data



Selected Publications

Statistical publications:

  • Doerken S, Zingg W, Wolkewitz M (2019). Estimating incidence and attributable length of stay – modelling the Swiss point prevalence data. Submitted.
  • Doerken S, Avalos M, Lagarde E et al. (2019). Penalized logistic regression with low prevalence exposures beyond high dimensional settings. PLOS ONE, 14(5):e0217057.
  • Doerken S, Mandel M, Zingg W, Wolkewitz M (2018). Use of prevalence data to study sepsis incidence and mortality in intensive care units. The Lancet Infectious Diseases, 18(3), 252.
  • Doerken S, De Bin R, Sauerbrei W (2018). Graphical tools for investigating variable selection instability caused by correlated variables. Unpublished.
  • Doerken S, Schumacher M, Baumdicker F (2018). Game time: statistical contests in the classroom. arXiv:1809.04338 [stat.OT]
  • Doerken S, Mockenhaupt M, Naldi L, Schumacher M, Sekula P. (2016). The case-crossover design via penalized regression. BMC Medical Research Methodology, 16(103).
  • Doerken S, Mockenhaupt M, Schumacher M, Sekula P. (2014). Assessment of the “case-chaos” design as an adjunct to the case-control design. American Journal of Epidemiology, 179(6), 775-780.


Medical publications:

  • Ganter J, Hellwig E, Doerken S, et al. (2019) In vitro evaluation of the cariogenic potential of rebaudioside A compared to sucrose and xylitol. Clinical oral investigations. 23(1):1-10.
  • Kohal R, ..., Doerken S, et al. (2018). Fatigue resistance of a two-piece zirconia oral implant. An investigation in the chewing simulator. Clinical Oral Implants Research, 29(17), 54-54.
  • Spies BC, ..., Doerken S, et al. (2018). Stability and aging resistance of a zirconia oral implant using a carbon fiber-reinforced screw for implant-abutment connection. Dental Materials, 34(10), 1585-1595.
  • Pieralli S, Kohal RJ, Hernandez EL, Doerken S, Spies BC (2018). Osseointegration of zirconia dental implants in animal investigations: A systematic review and meta-analysis. Dental Materials, 34(2), 171-182.
  • Speckmann C, Doerken S et al. (2017).  A prospective study on the natural history of patients with profound combined immunodeficiency (P-CID): An interim analysis. Journal of Allergy and Clinical Immunology, 139(4), 1302-1310.
  • Vry J, ..., Doerken S et al. (2016). European Cross-Sectional Survey of Current Care Practices for Duchenne Muscular Dystrophy Reveals Regional and Age-Dependent Differences. Journal of Neuromuscular Diseases, 3(4), 517-527.
  • Speckmann C, ..., Doerken S et al. (2015). A prospective study on the natural history of patients with profound combined immunodeficiency (P-CID). Lymphosign Journal, 2(2), 91-106.



University of Freiburg Research Database:

[2020] [2019] [2018] [2017] [2016] [Older publications]

Short CV

2015 - 2019 



PhD in Mathematics

Faculty of Mathematics and Physics, Freiburg University

PhD thesis: Penalized regression methods with sparse variables for modeling binary outcomes

2012 - 2019


Research statistician

Institute for Medical Biometry and Statistics, Medical Center - University of Freiburg

2013 - 2019 

Medical statistician

Center for Chronic Immunodeficiency, Medical Center - University of Freiburg

2016 - 2017 

Statistical consultant

Center for Dental Medicine, Medical Center - University of Freiburg

2005 - 2011 



Diploma in Mathematics

Faculty of Mathematics and Computer Science, Heidelberg University

Diploma thesis: Probabilistic Forecasting of U.S. Treasury Bills


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