Willi Sauerbrei

Summary

Affiliation: University of Freiburg
Country: Germany

Publications

  1. ncbi request reprint Prognostic factors. Confusion caused by bad quality design, analysis and reporting of many studies
    Willi Sauerbrei
    Abteilung Medizinische Biometrie und Statistik, Institut für Medizinische Biometrie und Medizinische Informatik, Universitatsklinikum Freiburg, Freiburg, Deutschland
    Adv Otorhinolaryngol 62:184-200. 2005
  2. ncbi request reprint Modelling to extract more information from clinical trials data: On some roles for the bootstrap
    Willi Sauerbrei
    Institute of Medical Biometry and Medical Informatics, University Medical Center Freiburg, Stefan Meier Strasse 26, 79104 Freiburg, Germany
    Stat Med 26:4989-5001. 2007
  3. doi request reprint Interactions between treatment and continuous covariates: a step toward individualizing therapy
    Patrick Royston
    J Clin Oncol 26:1397-9. 2008
  4. ncbi request reprint Differentiation of benign and malignant breast tumors by logistic regression and a classification tree using Doppler flow signals
    W Sauerbrei
    Institute of Medical Biometry and Informatics, University of Freiburg, Germany
    Methods Inf Med 37:226-34. 1998
  5. ncbi request reprint Selection of important variables and determination of functional form for continuous predictors in multivariable model building
    Willi Sauerbrei
    Institute of Medical Biometry and Medical Informatics, University Medical Center Freiburg, Stefan Meier Strasse 26, 79104 Freiburg, Germany
    Stat Med 26:5512-28. 2007
  6. pmc Investigation of continuous effect modifiers in a meta-analysis on higher versus lower PEEP in patients requiring mechanical ventilation--protocol of the ICEM study
    Benjamin Kasenda
    Department of Medical Biometry and Medical Informatics, University Medical Center Freiburg, Freiburg, Germany
    Syst Rev 3:46. 2014
  7. pmc Individual participant data meta-analysis of prognostic factor studies: state of the art?
    Ghada Abo-Zaid
    European Centre for Environment and Human Health, Peninsula College of Medicine and Dentistry, University of Exeter Knowledge Spa Royal Cornwall Hospital Truro, Cornwall TR1 3HD UK
    BMC Med Res Methodol 12:56. 2012
  8. pmc Reporting recommendations for tumor marker prognostic studies (REMARK): explanation and elaboration
    Douglas G Altman
    Centre for Statistics in Medicine, University of Oxford, UK
    BMC Med 10:51. 2012
  9. ncbi request reprint A new proposal for multivariable modelling of time-varying effects in survival data based on fractional polynomial time-transformation
    Willi Sauerbrei
    Institute of Medical Biometry and Medical Informatics, University Hospital of Freiburg, Stefan Meier Strasse 26, 79104 Freiburg, Germany
    Biom J 49:453-73. 2007
  10. doi request reprint A new strategy for meta-analysis of continuous covariates in observational studies
    Willi Sauerbrei
    IMBI, Freiburg University Medical Center, Stefan Meier Str 26, 79100, Freiburg, Germany
    Stat Med 30:3341-60. 2011

Collaborators

Detail Information

Publications29

  1. ncbi request reprint Prognostic factors. Confusion caused by bad quality design, analysis and reporting of many studies
    Willi Sauerbrei
    Abteilung Medizinische Biometrie und Statistik, Institut für Medizinische Biometrie und Medizinische Informatik, Universitatsklinikum Freiburg, Freiburg, Deutschland
    Adv Otorhinolaryngol 62:184-200. 2005
    ..Specifically, experienced statisticians have to play a central role in the planning, analysis, interpretation and reporting of these studies...
  2. ncbi request reprint Modelling to extract more information from clinical trials data: On some roles for the bootstrap
    Willi Sauerbrei
    Institute of Medical Biometry and Medical Informatics, University Medical Center Freiburg, Stefan Meier Strasse 26, 79104 Freiburg, Germany
    Stat Med 26:4989-5001. 2007
    ..To conclude, a discussion of the future of modelling and the future of the bootstrap is given...
  3. doi request reprint Interactions between treatment and continuous covariates: a step toward individualizing therapy
    Patrick Royston
    J Clin Oncol 26:1397-9. 2008
  4. ncbi request reprint Differentiation of benign and malignant breast tumors by logistic regression and a classification tree using Doppler flow signals
    W Sauerbrei
    Institute of Medical Biometry and Informatics, University of Freiburg, Germany
    Methods Inf Med 37:226-34. 1998
    ..The results indicate that the estimates of sensitivity and specificity are probably close to realistic values for a clinical setting...
  5. ncbi request reprint Selection of important variables and determination of functional form for continuous predictors in multivariable model building
    Willi Sauerbrei
    Institute of Medical Biometry and Medical Informatics, University Medical Center Freiburg, Stefan Meier Strasse 26, 79104 Freiburg, Germany
    Stat Med 26:5512-28. 2007
    ..While acknowledging that further research is needed, we argue why MFP is our preferred approach for multivariable model building with continuous covariates...
  6. pmc Investigation of continuous effect modifiers in a meta-analysis on higher versus lower PEEP in patients requiring mechanical ventilation--protocol of the ICEM study
    Benjamin Kasenda
    Department of Medical Biometry and Medical Informatics, University Medical Center Freiburg, Freiburg, Germany
    Syst Rev 3:46. 2014
    ..This also applies to a therapeutic context where investigators of randomized clinical trials (RCTs) are interested in interactions between treatment assignment and one or more continuous predictors...
  7. pmc Individual participant data meta-analysis of prognostic factor studies: state of the art?
    Ghada Abo-Zaid
    European Centre for Environment and Human Health, Peninsula College of Medicine and Dentistry, University of Exeter Knowledge Spa Royal Cornwall Hospital Truro, Cornwall TR1 3HD UK
    BMC Med Res Methodol 12:56. 2012
    ..We assessed the feasibility and conduct of this approach...
  8. pmc Reporting recommendations for tumor marker prognostic studies (REMARK): explanation and elaboration
    Douglas G Altman
    Centre for Statistics in Medicine, University of Oxford, UK
    BMC Med 10:51. 2012
    ..In this paper we expand on the REMARK checklist to enhance its use and effectiveness through better understanding of the intent of each item and why the information is important to report...
  9. ncbi request reprint A new proposal for multivariable modelling of time-varying effects in survival data based on fractional polynomial time-transformation
    Willi Sauerbrei
    Institute of Medical Biometry and Medical Informatics, University Hospital of Freiburg, Stefan Meier Strasse 26, 79104 Freiburg, Germany
    Biom J 49:453-73. 2007
    ..Non-linear time-fixed effects are found for progesterone receptor status and number of positive lymph nodes. Highly statistically significant time-varying effects are present for progesterone receptor status and tumour size...
  10. doi request reprint A new strategy for meta-analysis of continuous covariates in observational studies
    Willi Sauerbrei
    IMBI, Freiburg University Medical Center, Stefan Meier Str 26, 79100, Freiburg, Germany
    Stat Med 30:3341-60. 2011
    ..We further discuss some general issues that are found in meta-analyses of observational studies...
  11. doi request reprint Stability investigations of multivariable regression models derived from low- and high-dimensional data
    Willi Sauerbrei
    Institute of Medical Biometry and Informatics, University Medical Center Freiburg, Freiburg, Germany
    J Biopharm Stat 21:1206-31. 2011
    ..While some areas are indicated where resampling techniques for model building still need further refinement, our case studies illustrate that these techniques can already be recommended for wider use...
  12. doi request reprint Comparison of procedures to assess non-linear and time-varying effects in multivariable models for survival data
    Anika Buchholz
    Department of Medical Biometry and Statistics, Institute of Medical Biometry and Medical Informatics, University Medical Center Freiburg, Stefan Meier Strasse 26, 79104 Freiburg, Germany
    Biom J 53:308-31. 2011
    ..In three examples we will compare five recently published strategies to assess whether and how the effects of covariates from a multivariable model vary in time. For practical use we will give some recommendations...
  13. ncbi request reprint Confidence intervals for the effect of a prognostic factor after selection of an 'optimal' cutpoint
    Norbert Holländer
    Institute of Medical Biometry and Medical Informatics, University Hospital Freiburg, Stefan Meier Strasse 26, Freiburg D 79104, Germany
    Stat Med 23:1701-13. 2004
    ....
  14. ncbi request reprint Assessment of breast cancer vascularisation by Doppler ultrasound as a prognostic factor of survival
    Dirk Watermann
    Department of Obstetrics and Gynaecology, Freiburg University Medical Centre, 79106 Freiburg, Germany
    Oncol Rep 11:905-10. 2004
    ..69 (1.33-5.41) for number of tumor arteries; RR 2.84 (1.27-6.34) for angioinvasion]. Tumor vascularisation detected by Doppler ultrasound appears to be an independent predictor of overall survival in women with early breast cancer...
  15. ncbi request reprint Multivariate analysis of prognostic factors in patients with glioblastoma
    Johannes Lutterbach
    Department of Radiotherapy, Radiologic University Hospital, Freiburg i Br, Germany
    Strahlenther Onkol 179:8-15. 2003
    ..To identify prognostic factors for overall survival in patients with newly diagnosed glioblastoma undergoing radiation therapy...
  16. doi request reprint On stability issues in deriving multivariable regression models
    Willi Sauerbrei
    Department für Medizinische Biometrie und Medizinische Informatik, Universitatsklinikum Freiburg, Stefan Meier Str 26, 79104, Freiburg, Germany
    Biom J 57:531-55. 2015
    ....
  17. doi request reprint Comparison between splines and fractional polynomials for multivariable model building with continuous covariates: a simulation study with continuous response
    Harald Binder
    Institute of Medical Biostatistics, Epidemiology and Informatics, University Medical Center of Johannes Gutenberg University Mainz, 55101 Mainz, Germany
    Stat Med 32:2262-77. 2013
    ..MFP better recovers simpler functions, whereas splines better recover more complex functions. For a large amount of information and no local structure, MFP and the spline procedures often select similar explanatory models...
  18. ncbi request reprint Intraperitoneal adenovirus-mediated suicide gene therapy in combination with either topotecan or paclitaxel in nude mice with human ovarian cancer
    Dirk G Kieback
    Department of Obstetrics and Gynecology, Freiburg University Medical Center, Freiburg, Germany
    Cancer Gene Ther 9:478-81. 2002
    ..The effect of dose varied strongly with time. Mice treated with high-dose chemotherapy had a substantially increased risk of dying in the time period following application, whereas this advantage of the lower dose disappeared later...
  19. ncbi request reprint Tumor stage and early mortality for surgical resections in lung cancer
    Erich Stoelben
    Department of Thoracic Surgery, University Hospital, 79106, Freiburg, Germany
    Langenbecks Arch Surg 388:116-21. 2003
    ..Postoperative mortality rates have been published in relation to operative procedure or preexisting pulmonary and extrapulmonary diseases. We analyzed our patients for the effect of the postoperative tumor stage on perioperative mortality...
  20. ncbi request reprint A new measure of prognostic separation in survival data
    Patrick Royston
    Cancer Division, MRC Clinical Trials Unit, London NW1 2DA, UK
    Stat Med 23:723-48. 2004
    ..We study the properties of the measure by simulation and by example in three substantial data sets. We believe that our new measure will prove useful as a tool to evaluate the separation available-with a prognostic model...
  21. ncbi request reprint A new approach to modelling interactions between treatment and continuous covariates in clinical trials by using fractional polynomials
    Patrick Royston
    MRC Clinical Trials Unit, 222 Euston Road, London NW1 2DA, UK
    Stat Med 23:2509-25. 2004
    ..We demonstrate the ability of the approach to detect and display treatment/covariate interactions in two examples from controlled trials in cancer...
  22. ncbi request reprint REporting recommendations for tumor MARKer prognostic studies (REMARK)
    Lisa M McShane
    National Cancer Institute, Biometric Research Branch, Bethesda, MD 20892 7434, USA
    Nat Clin Pract Urol 2:416-22. 2005
    ....
  23. ncbi request reprint Identification of clinically useful cancer prognostic factors: what are we missing?
    Lisa M McShane
    J Natl Cancer Inst 97:1023-5. 2005
  24. ncbi request reprint REporting recommendations for tumour MARKer prognostic studies (REMARK)
    Lisa M McShane
    National Cancer Institute, Biometric Research Branch, DCTD, Room 8126, Executive Plaza North, MSC 7434, 6130 Executive Boulevard, Bethesda, MD 20892 7434, USA
    Eur J Cancer 41:1690-6. 2005
    ....
  25. ncbi request reprint Reporting recommendations for tumor marker prognostic studies (REMARK)
    Lisa M McShane
    Biometric Research Branch, National Cancer Institute, Executive Plaza North, 6130 Executive Blvd, Bethesda, MD 20892 7434, USA
    J Natl Cancer Inst 97:1180-4. 2005
    ....
  26. ncbi request reprint REporting recommendations for tumor MARKer prognostic studies (REMARK)
    Lisa M McShane
    National Cancer Institute, Biometric Research Branch, DCTD, Room 8126, Executive Plaza North, MSC 7434, 6130 Executive Boulevard, Bethesda, MD 20892 7434, USA
    Nat Clin Pract Oncol 2:416-22. 2005
    ....
  27. ncbi request reprint Reporting recommendations for tumor marker prognostic studies
    Lisa M McShane
    Biometric Research Branch, National Cancer Institute, Bethesda, MD, USA
    J Clin Oncol 23:9067-72. 2005
  28. ncbi request reprint REporting recommendations for tumor MARKer prognostic studies (REMARK)
    Lisa M McShane
    Biometric Research Branch, DCTD, National Cancer Institute, Room 8126, Executive Plaza North, 6130 Executive Boulevard, Bethesda, MD 20892 7434, USA
    Breast Cancer Res Treat 100:229-35. 2006
    ....
  29. ncbi request reprint Dichotomizing continuous predictors in multiple regression: a bad idea
    Patrick Royston
    MRC Clinical Trials Unit, 222 Euston Road, London NW1 2DA, UK
    Stat Med 25:127-41. 2006
    ..Dichotomization of continuous data is unnecessary for statistical analysis and in particular should not be applied to explanatory variables in regression models...