Research Topics
| R BenderSummaryCountry: Germany Publications
| Collaborators
|
Detail Information
Publications
Generating survival times to simulate Cox proportional hazards modelsRalf Bender
Institute for Quality and Efficiency in Health Care, Cologne, Germany
Stat Med 24:1713-23. 2005....
Reporting of loss to follow-up information in randomised controlled trials with time-to-event outcomes: a literature surveyElke Vervölgyi
Institute for Quality and Efficiency in Health Care IQWiG, Dillenburger Str 27, 51105 Cologne, Germany
BMC Med Res Methodol 11:130. 2011..To assess the reporting of loss to follow-up (LTFU) information in articles on randomised controlled trials (RCTs) with time-to-event outcomes, and to assess whether discrepancies affect the validity of study results...
Calculation of NNTs in RCTs with time-to-event outcomes: a literature reviewMandy Hildebrandt
Institute for Quality and Efficiency in Health Care IQWiG, Cologne, Germany
BMC Med Res Methodol 9:21. 2009..The frequency of using NNTs to report results of randomised controlled trials (RCT) investigating time-to-event outcomes and the adequacy of the applied calculation methods are unknown...
Calculating confidence intervals for impact numbersMandy Hildebrandt
Department of Medical Biometry, Institute for Quality and Efficiency in Health Care IQWiG, Dillenburger Str, 27, 51105 Cologne, Germany
BMC Med Res Methodol 6:32. 2006..In this paper, we present methods to calculate confidence intervals for the new impact numbers in the situation of cohort studies...
Predicting the risk of falling--efficacy of a risk assessment tool compared to nurses' judgement: a cluster-randomised controlled trial [ISRCTN37794278]Gabriele Meyer
Unit of Health Sciences and Education, University of Hamburg, Martin Luther King Platz 6, D 20146 Hamburg, Germany
BMC Geriatr 5:14. 2005..Other measures are fall related injuries, hospital admissions and consultations with a physician, and costs...
[What is the p-value?]R Bender
Institut für Qualität und Wirtschaftlichkeit im Gesundheitswesen, Koln, Germany
Dtsch Med Wochenschr 132:e15-6. 2007
[The 2 by 2 table]R Bender
, , Germany
Dtsch Med Wochenschr 132:e12-4. 2007
[What is a confidence interval?]R Bender
Institut für Qualität und Wirtschaftlichkeit im Gesundheitswesen, Koln, Germany
Dtsch Med Wochenschr 132:e17-8. 2007
[Serial data curves]R Bender
, , Germany
Dtsch Med Wochenschr 132:e22-3. 2007
[Common significance tests]R Bender
, , Germany
Dtsch Med Wochenschr 132:e24-5. 2007
Estimating adjusted NNTs in randomised controlled trials with binary outcomes: a simulation studyRalf Bender
Department of Medical Biometry, Institute for Quality and Efficiency in Health Care IQWiG, D 51105 Cologne, Germany
Contemp Clin Trials 31:498-505. 2010..Therefore, it is preferable to adjust for balanced covariates in RCTs when the treatment effect is expressed in terms of risk differences and NNTs and the covariate represents a strong predictor...
[Multiple testing]R Bender
, , Germany
Dtsch Med Wochenschr 132:e26-9. 2007
[Multiple regression]R Bender
, , Germany
Dtsch Med Wochenschr 132:e30-2. 2007
[Analysis of variance]R Bender
, , Germany
Dtsch Med Wochenschr 132:e57-60. 2007
[Analysis of variance for repeated measurements]R Bender
, , Germany
Dtsch Med Wochenschr 132:e61-4. 2007
Estimating adjusted NNT measures in logistic regression analysisRalf Bender
Department of Medical Biometry, Institute for Quality and Efficiency in Health Care IQWiG, Cologne, Germany
Stat Med 26:5586-95. 2007..The proposed method is illustrated by application to data of a cohort study investigating the effect of smoking on coronary heart disease...
Attention should be given to multiplicity issues in systematic reviewsRalf Bender
Institute for Quality and Efficiency in Health Care, Dillenburger Street 27, Cologne, Germany
J Clin Epidemiol 61:857-65. 2008..The objective of this paper is to describe the problem of multiple comparisons in systematic reviews and to provide some guidelines on how to deal with it in practice...
[Logistic regression]R Bender
, , Germany
Dtsch Med Wochenschr 132:e33-5. 2007
Causes of death in obesity: relevant increase in cardiovascular but not in all-cancer mortalityRalf Bender
Institute for Quality and Efficiency in Health Care, Dillenburger Str 27, Cologne D 51105, Germany
J Clin Epidemiol 59:1064-71. 2006..To assess the relation between body mass index (BMI) and the risk of death from various causes in a prospective cohort study...
[Possibilities and limitations of statistical regression models for the calculation of threshold values for minimum provider volumes]Ralf Bender
Institut für Qualität und Wirtschaftlichkeit im Gesundheitswesen, Koln
Z Arztl Fortbild Qualitatssich 100:93-8. 2006..In order to verify that a minimum provider volume leads to the expected quality improvement, a prospective intervention study is required...
Tutorial: using confidence curves in medical researchRalf Bender
Institute for Quality and Efficiency in Health Care, Cologne, Germany
Biom J 47:237-47. 2005..In medical research more emphasis on the choice between the one- and two-sided approaches should be given. One- and two-sided confidence curves are useful complements to the conventional methods of presenting study results...
Risk of malignancies in patients with diabetes treated with human insulin or insulin analogues: a cohort studyL G Hemkens
Institute for Quality and Efficiency in Health Care IQWiG, Dillenburger Strasse 27, D 51105, Cologne, Germany
Diabetologia 52:1732-44. 2009..The aim of this cohort study was to investigate the risk of malignant neoplasms and mortality in patients with diabetes treated either with human insulin or with one of three insulin analogues...
[The kappa coefficient]U Grouven
, , Germany
Dtsch Med Wochenschr 132:e65-8. 2007
[Linear regression and correlation]S Lange
, , Germany
Dtsch Med Wochenschr 132:e9-11. 2007
[Comparing methods of measurement]U Grouven
, , Germany
Dtsch Med Wochenschr 132:e69-73. 2007
[Measures of variability]S Lange
, , Germany
Dtsch Med Wochenschr 132:e5-6. 2007
[Equivalence and non-inferiority trials]S Lange
, , Germany
Dtsch Med Wochenschr 132:e53-6. 2007
[Quantiles, cumulative distribution function, and box-plot]S Lange
, , Germany
Dtsch Med Wochenschr 132:e3-4. 2007
Introduction to the use of regression models in epidemiologyRalf Bender
Institute for Quality and Efficiency in Health Care, Cologne, Germany
Methods Mol Biol 471:179-95. 2009..This chapter provides a nontechnical introduction to these regression models with illustrating examples from cancer research...
Flexible regression models are useful tools to calculate and assess threshold values in the context of minimum provider volumesUlrich Grouven
Institute for Quality and Efficiency in Health Care, Cologne, Germany
J Clin Epidemiol 61:1125-31. 2008..The aim was to review different approaches for the derivation of threshold values and to discuss their strengths and limitations in the context of minimum provider volumes...
[Assessment of the number of cardio- and cerebrovascular events due to rofecoxib (Vioxx) in Germany between 2001 and 2004]Peter T Sawicki
Institut für Qualität und Wirtschaftlichkeit im Gesundheitswesen IQWiG, Koln
Med Klin (Munich) 101:191-7. 2006....
[Median or mean?]S Lange
Institut für Qualität und Wirtschaftlichkeit im Gesundheitswesen, Koln, Germany
Dtsch Med Wochenschr 132:e1-2. 2007
[What is a significance test? General issues]S Lange
Institut für Qualität und Wirtschaftlichkeit im Gesundheitswesen, Koln, Germany
Dtsch Med Wochenschr 132:e19-21. 2007
[The histogram]S Lange
, , Germany
Dtsch Med Wochenschr 132:e7-8. 2007
Intervention effects in the case of heterogeneity between three subgroups. Assessment within the framework of systematic reviewsG Skipka
Institute for Quality and Efficiency in Health Care, IQWiG, Dillenburger Str 27, 51105 Köln, Germany
Methods Inf Med 49:613-7. 2010..In this case, the problem of non-transitive relations may occur if the significance level is fixed at 0.05 for all tests...
Logistic regression was preferred to estimate risk differences and numbers needed to be exposed adjusted for covariatesUlrich Gehrmann
Department of Medical Biometry, Institute for Quality and Efficiency in Health Care IQWiG, Dillenburger Street 27, Cologne, Germany
J Clin Epidemiol 63:1223-31. 2010..A novel proposal is given by logistic regression with average risk difference (LR-ARD) estimation. Finally, the use of ordinary linear regression and unadjusted estimation can be considered...
Calculating the "number needed to be exposed" with adjustment for confounding variables in epidemiological studiesRalf Bender
Department of Epidemiology and Medical Statistics, School of Public Health, University of Bielefeld, PO Box 100131, D 33501 Bielefeld, Germany
J Clin Epidemiol 55:525-30. 2002..The adjusted number needed to be exposed can be a useful complement to the commonly presented results in epidemiological studies, such as ORs and attributable risks...
Body weight, blood pressure, and mortality in a cohort of obese patientsRalf Bender
Department of Epidemiology and Medical Statistics, School of Public Health, University of Bielefeld, Bielefeld, Germany
Am J Epidemiol 156:239-45. 2002..0, 2.7) but not for women (hazard ratio = 0.71, 95% confidence interval: 0.4, 1.2). These findings support previous observations that the risk of death is lower for hypertensive men in high compared with low BMI groups...
Effect of Berkson measurement error on parameter estimates in Cox regression modelsHelmut Kuchenhoff
Department of Statistics, Ludwig Maximilians Universitat, Akademiestr 1, 80799, Munchen, Germany
Lifetime Data Anal 13:261-72. 2007..Even the effect of a Berkson measurement error with high variance, which is not unrealistic in our example, is a negligible attenuation of the observed effect. However, this effect is more pronounced for multiplicative measurement error...
The impact of non-compliance with the therapeutic regimen on the development of stroke among hypertensive men and women in Gaza, PalestineBernhard T Baune
Department of Psychiatry and Psychotherapy, University of Muenster, Albert Schweitzer Street 11, D 48129 Muenster, Germany
Saudi Med J 25:1683-8. 2004..To identify potential risk factors we investigated compliance with the therapeutic regimen and life style factors which may increase the risk for stroke...
Generating survival times to simulate Cox proportional hazards models by Ralf Bender, Thomas Augustin and Maria Blettner, Statistics in Medicine 2005; 24:1713-1723Ralf Bender
Stat Med 25:1978-9. 2006
Confidence intervals for adjusted NNEs: a simulation studyRalf Bender
J Clin Epidemiol 56:205-6. 2003
Predictors of adherence to the use of hip protectors in nursing home residentsAndrea Warnke
Unit of Health Sciences and Education, University of Hamburg, Hamburg, Germany
J Am Geriatr Soc 52:340-5. 2004..To assess predictors of hip-protector use in nursing home residents under usual-care conditions and after intervention consisting of structured education of nurses and nursing home residents and provision of free hip protectors...
Eight-year trends in food, energy and macronutrient intake in a sample of elderly German subjectsSvenja M Jungjohann
Institute of Nutritional Science, Justus-Liebig-University, Goethestr. 55, D-35 390 Giessen, Germany
Br J Nutr 93:361-78. 2005..79 and -2.56 g/d per year). The healthier food choices and the ability to change food habits could be related to the relatively high health-awareness of the GISELA subjects compared to the federal average of equivalent age groups...
A new classification plot for the C-peptide suppression testChristiane Saddig
Department of Metabolic Diseases and Nutrition, Heinrich-Heine-University of Duesseldorf, Duesseldorf, Germany
JOP 3:16-25. 2002..Thus, the need for fasting tests and hospitalization costs can be reduced...
Flexible intensive insulin therapy in adults with type 1 diabetes and high risk for severe hypoglycemia and diabetic ketoacidosisAlexander Sämann
Department of Internal Medicine III, Friedrich Schiller University, 07740 Jena, Germany
Diabetes Care 29:2196-9. 2006..This study evaluates DTTP outcomes in patients at high risk for severe hypoglycemia and severe ketoacidosis...
Breastfeeding promotion in non-UNICEF-certified hospitals and long-term breastfeeding success in GermanyM Dulon
Department of Epidemiology and Medical Statistics, School of Public Health, University of Bielefeld, Germany
Acta Paediatr 92:653-8. 2003..81) and upbringing in East Germany (OR 2.27) were stronger. CONCLUSION: In unselected German hospitals even moderate levels of breastfeeding promotion identified by WHO/UNICEF criteria were associated with long-term breastfeeding success...
