T J Cleophas

Summary

Country: The Netherlands

Publications

  1. ncbi Clinical trials and p-values, beware of the extremes
    Ton J Cleophas
    Albert Schweitzer Hospital, Dordrecht, The Netherlands
    Clin Chem Lab Med 42:300-4. 2004
  2. ncbi Methods for improving clinical trials
    T J Cleophas
    European Interuniversity College of Pharmaceutical Medicine, Lyon, France
    Clin Chem Lab Med 37:1035-41. 1999
  3. ncbi Diabetics with hypertension not controlled with ACE inhibitors: alternate therapies
    T J Cleophas
    Department of Internal Medicine, Albert Schweitzer Hospital, Dordrecht, The Netherlands
    Angiology 52:469-75. 2001
  4. doi Handling categories properly: a novel objective of clinical research
    Ton J Cleophas
    European College Pharmaceutical Medicine, EC Socrates Project, Lyon, France
    Am J Ther 19:287-93. 2012
  5. doi A novel approach to noninferiority testing: documented proof rather than arbitrary margins
    Ton J Cleophas
    European College Pharmaceutical Medicine, Socrates Project European Community, Lyon, France
    Am J Ther 19:101-7. 2012
  6. doi Clinical research: a novel approach to the analysis of repeated measures
    Ton J Cleophas
    Albert Schweitzer Hospital, Dordrecht, Netherlands
    Am J Ther 19:e1-7. 2012
  7. ncbi Clinical trials: Renewed attention to the interpretation of the P values--review
    Ton J Cleophas
    European Interuniversity College of Pharmaceutical Medicine, Lyon, France
    Am J Ther 11:317-22. 2004
  8. ncbi Problems in regression modeling of randomized clinical trials
    T J Cleophas
    European Interuniversity College of Pharmaceutical Medicine, Lyon, France
    Int J Clin Pharmacol Ther 43:23-9. 2005
  9. ncbi Nationwide efficacy-safety study of nebivolol in mildly hypertensive patients
    T J Cleophas
    Department Medicine, Albert Schweitzer Hospital, Dordrecht, Netherlands
    Am J Ther 13:192-7. 2006
  10. ncbi Meta-analysis
    Ton J Cleophas
    European College of Pharmaceutical Medicine, Lyon, France
    Circulation 115:2870-5. 2007

Collaborators

Detail Information

Publications39

  1. ncbi Clinical trials and p-values, beware of the extremes
    Ton J Cleophas
    Albert Schweitzer Hospital, Dordrecht, The Netherlands
    Clin Chem Lab Med 42:300-4. 2004
    ..Statistical tests are, traditionally, not very good at distinguishing between errors and outliers, but they should be able to point out main endpoint results closer to expectation than compatible with random sampling...
  2. ncbi Methods for improving clinical trials
    T J Cleophas
    European Interuniversity College of Pharmaceutical Medicine, Lyon, France
    Clin Chem Lab Med 37:1035-41. 1999
    ..adjusting for asymmetries not only of patient characteristics but also of outcome variables; 4. accounting routinely for type III errors; 5. routinely weighing benefits of a new drug against risks...
  3. ncbi Diabetics with hypertension not controlled with ACE inhibitors: alternate therapies
    T J Cleophas
    Department of Internal Medicine, Albert Schweitzer Hospital, Dordrecht, The Netherlands
    Angiology 52:469-75. 2001
    ..At least two mechanisms may be involved: withdrawal of a pressor effect from the beta-blocker, and calcium-channel-mediated vasodilation...
  4. doi Handling categories properly: a novel objective of clinical research
    Ton J Cleophas
    European College Pharmaceutical Medicine, EC Socrates Project, Lyon, France
    Am J Ther 19:287-93. 2012
    ..This approach does not always fit the data patterns causing negative results as demonstrated in the examples of this article. We recommend that such variables be recoded into categorical dummy variables...
  5. doi A novel approach to noninferiority testing: documented proof rather than arbitrary margins
    Ton J Cleophas
    European College Pharmaceutical Medicine, Socrates Project European Community, Lyon, France
    Am J Ther 19:101-7. 2012
    ....
  6. doi Clinical research: a novel approach to the analysis of repeated measures
    Ton J Cleophas
    Albert Schweitzer Hospital, Dordrecht, Netherlands
    Am J Ther 19:e1-7. 2012
    ..We hope that this article will encourage clinical researchers to make use of its benefits more often...
  7. ncbi Clinical trials: Renewed attention to the interpretation of the P values--review
    Ton J Cleophas
    European Interuniversity College of Pharmaceutical Medicine, Lyon, France
    Am J Ther 11:317-22. 2004
    ..Very large P values are not compatible with a normal gaussian frequency distribution; very small P values do not completely confirm prior expectations. They must be scrutinized and may have been inadequately improved...
  8. ncbi Problems in regression modeling of randomized clinical trials
    T J Cleophas
    European Interuniversity College of Pharmaceutical Medicine, Lyon, France
    Int J Clin Pharmacol Ther 43:23-9. 2005
    ..Data modeling can be applied to improving the precision of clinical studies and multiple regression modeling is increasingly used for this purpose...
  9. ncbi Nationwide efficacy-safety study of nebivolol in mildly hypertensive patients
    T J Cleophas
    Department Medicine, Albert Schweitzer Hospital, Dordrecht, Netherlands
    Am J Ther 13:192-7. 2006
    ..The efficacy of nebivolol as monotherapy and as the efficacy as add-on therapy are very similar. Nebivolol is highly efficacious in patients with ISH...
  10. ncbi Meta-analysis
    Ton J Cleophas
    European College of Pharmaceutical Medicine, Lyon, France
    Circulation 115:2870-5. 2007
  11. ncbi Clinical trials are often false positive: a review of simple methods to control this problem
    Ton J Cleophas
    European College of Pharmaceutical Medicine, Lyon, France
    Curr Clin Pharmacol 1:1-4. 2006
    ..This result is based on the play of chance. In current clinical trials, instead of a single efficacy-variable of one treatment, multiple efficacy-variables of more than one treatment are increasingly assessed...
  12. ncbi Novel procedures for validating surrogate endpoints in clinical trials
    Ton J Cleophas
    Department of Medicine, Albert Schweitzer Hospital, Dordrecht, Netherlands
    Curr Clin Pharmacol 2:123-8. 2007
    ..The problem with (1) is that an overall level of validity is hard to achieve, and with (2) is that a significant correlation between the surrogate and true endpoint is not enough to indicate that the surrogate is a valid predictor...
  13. ncbi Clinical trials: how to assess confounding and why so
    Ton J Cleophas
    Dept Medicine, Albert Schweitzer Hospital, Dordrecht, The Netherlands
    Curr Clin Pharmacol 2:129-33. 2007
    ..However, irrelevant covariates and very large / small ORs reduce power and reliability of the assessment. The above methods can not be used for the assessment of interaction in the data...
  14. ncbi Validating diagnostic tests, correct and incorrect methods, new developments
    Ton J Cleophas
    Department of Internal Medicine, Albert Schweitzer Hospital, Dordrecht, The Netherlands
    Curr Clin Pharmacol 3:70-6. 2008
    ..Particularly, accuracy-, reproducibility- and precision-assessments have been recommended, but methods of assessment have not been defined so far...
  15. doi Meta-analyses of diagnostic studies
    Ton J Cleophas
    European Interuniversity College of Pharmaceutical Medicine, Lyon, France
    Clin Chem Lab Med 47:1351-4. 2009
    ..The diagnostic odds ratio (DOR), defined as the odds of true positives vs. that of false positives, may avoid this problem. The aim of the study was to review the advantages and limitations of the DORs...
  16. doi Artificial intelligence for diagnostic purposes: principles, procedures and limitations
    Ton J Cleophas
    European College Pharmaceutical Medicine, Lyon, France
    Clin Chem Lab Med 48:159-65. 2010
    ..The objective of this study was to review the principles, procedures, and limitations of BP artificial neural networks for a non-mathematical readership...
  17. doi Item response modelling for clinical and laboratory testing
    Ton J Cleophas
    European College Pharmaceutical Medicine, Lyon, France
    Eur J Clin Invest 40:911-7. 2010
    ..Item response models using exponential modelling are more sensitive than classical linear methods for making predictions from psychological questionnaires...
  18. ncbi Age-related decline in autonomic control of blood pressure: implications for the pharmacological management of hypertension in the elderly
    Ton J Cleophas
    Department of Medicine, Albert Schweitzer Hospitals, Dordrecht, The Netherlands
    Drugs Aging 20:313-9. 2003
    ..In elderly patients beta-blockers may, therefore, be the most appropriate antihypertensive agents as they protect the elderly from orthostatic impairment...
  19. ncbi Paradoxical pressor effects of beta-blockers in standing elderly patients with mild hypertension: a beneficial side effect
    T J Cleophas
    Albert Schweitzer Hospital, Dordrecht, The Netherlands
    Circulation 105:1669-71. 2002
    ..beta-blockers cause pressor effects in standing patients with autonomic neuropathy, but their effects on standing pulse pressures in elderly subjects with mild hypertension have not been systematically studied...
  20. ncbi Homocysteine, a risk factor for coronary artery disease or not? A meta-analysis
    T J Cleophas
    Department of Medicine, Albert Schweitzer Hospital, Dordrecht, The Netherlands
    Am J Cardiol 86:1005-9, A8. 2000
    ..At the same time, however, homocysteine may be an indicator for unhealthy lifestyles, and therefore, an important variable for cardiologists to take into account when assessing coronary artery disease...
  21. ncbi Beta-blockers and heart failure: meta-analysis of mortality trials
    T J Cleophas
    European College of Pharmaceutical Medicine, Lyon, France
    Int J Clin Pharmacol Ther 39:383-8. 2001
    ..g. arrhythmias, then alternative antiarrhythmic agents may serve equally well or better than beta-blockers and with fewer side effects...
  22. ncbi Meta-analysis of efficacy and safety of second-generation dihydropyridine calcium channel blockers in heart failure
    T J Cleophas
    Department of Medicine, Albert Schweitzer Hospital, Dordrecht, The Netherlands
    Am J Cardiol 87:487-90, A7-8. 2001
    ..A 6% reduction in mortality was found, which, although not significantly different from 0%, does indicate that these drugs do not increase mortality in this category of patients...
  23. ncbi Limitations of randomized clinical trials. Proposed alternative designs
    T J Cleophas
    European Interuniversity College of Pharmaceutical Medicine, Dordrecht, Netherlands
    Clin Chem Lab Med 38:1217-23. 2000
    ..Objectives are to identify what a classical clinical trial cannot manage, to summarize and discuss alternative trial designs that are helpful for such purposes...
  24. ncbi Daytime-selective antihypertensive activity of celiprolol
    T J Cleophas
    Department of Medicine, Merwede Hospital Dordrecht, The Netherlands
    Angiology 50:797-803. 1999
    ....
  25. ncbi Celiprolol and propranolol for unstable angina pectoris
    T J Cleophas
    Department of Medicine, Merwede Hospital Sliedrecht Dordrecht, The Netherlands
    Clin Pharmacol Ther 57:67-72. 1995
    ..Celiprolol, a novel beta-blocker, may be more effective than propranolol in unstable angina pectoris because of both its beta 1-receptor selectivity and its vasodilatory property...
  26. ncbi Quality of life before and during antihypertensive treatment: a comparative study of celiprolol and atenolol
    T J Cleophas
    Department of Medicine, Merwede Hospital Dordrecht, Netherlands
    Int J Clin Pharmacol Ther 34:312-7. 1996
    ..Some recently developed antihypertensive agents have been suggested to be devoid of these deleterious effects on well-being expressed as quality of life...
  27. ncbi Nebivolol: a review of its clinical and pharmacological characteristics
    W Gielen
    European College of Pharmaceutical Medicine, Lyon, France
    Int J Clin Pharmacol Ther 44:344-57. 2006
    ..The beneficial effects on endothelial function, autonomic control and exercise capacity are of considerable clinical interest...
  28. ncbi Amplified amplitudes of circadian rhythms and nighttime hypotension in patients with chronic fatigue syndrome: improvement by inopamil but not by melatonin
    L van de Luit
    Department of Medicine, Merwede Hospital Dordrecht, The Netherlands
    Angiology 49:903-8. 1998
    ..Patients with CFS have increased amplitudes of circadian rhythms and systolic blood pressures consistently below 100 mm Hg during the nighttime. Positive inotropic compounds may be beneficial in such patients, but melatonin may not be...
  29. ncbi Random effects models in clinical research
    T J Cleophas
    Albert Schweitzer Hospital, Dordrecht, The Netherlands
    Int J Clin Pharmacol Ther 46:421-7. 2008
    ..The latter situation requires a random effects model...
  30. ncbi Quality of life before and during antihypertensive treatment: a comparative study of celiprolol and atenolol
    T J Cleophas
    Department of Medicine, Merwede Hospital Dordrecht, Sliedrecht, Netherlands
    Am J Ther 4:117-22. 1997
    ..Our results show that the selective beta-blocker with vasodilatory property celiprolol is at least as effective as atenolol and that it is more advantageous in terms of some quality of life variables...
  31. ncbi Prevalence of iatrogenic admissions to the Departments of Medicine/Cardiology/ Pulmonology in a 1,250 bed general hospital
    R Atiqi
    Department of Medicine, Albert Schweitzer Hospital, Dordrecht, Netherlands
    Int J Clin Pharmacol Ther 48:517-24. 2010
    ..3. Most often iatrogenic admissions were observed with cardiac disease, hypertension, gastrointestinal conditions, anticoagulant treatment, and use of NSAIDs...
  32. ncbi Celiprolol vs propranolol in unstable angina pectoris: a double-blind, randomized, parallel-group study
    T J Cleophas
    Department of Internal Medicine, Merwede Hospital Sliedrecht Dordrecht, Leyden, The Netherlands
    Angiology 46:137-44. 1995
    ....
  33. ncbi Meta-analysis of recent studies on patients admitted to hospital due to adverse drug effects
    R Atiqi
    Department of Medicine, Albert Schweitzer Hospital, Dordrecht, The Netherlands
    Int J Clin Pharmacol Ther 47:549-55. 2009
    ..7%, 3.1 - 6.2). The studies were clinically very heterogeneous with percentages of ADEs between 3.4 and 33.2%. The nature of the patient group could be held largely responsible for the clinical heterogeneity observed...
  34. pmc Methods for analysing cardiovascular studies with repeated measures
    T J Cleophas
    European Interuniversity College of Pharmaceutical Medicine, Lyon, France and Department of Statistics, Circulation, Boston, USA
    Neth Heart J 17:429-33. 2009
    ..The purpose of this review was not to present a complete report but, rather, to underline that ample efforts should be made to account for the special nature of repeated measures. (Neth Heart J 2009;17:429-33.)...
  35. ncbi Variability in clinical data is often more useful than the mean: illustration of concept and simple methods of assessment
    A H Zwinderman
    European Interuniversity College of Pharmaceutical Medicine, Lyon, France
    Int J Clin Pharmacol Ther 43:536-42. 2005
    ..Clinical investigators, although they are generally familiar with testing differences between averages, have difficulty testing differences between variabilities...
  36. pmc Lifestyle interventions in the management of hypertension: a survey based on the opinion of 105 practitioners
    S Elhani
    Albert Schweitzer Hospital, Dordrecht, and Hoge School Utrecht, The Netherlands
    Neth Heart J 17:9-12. 2009
    ..Lifestyle interventions in the management of hypertension were beneficial in published studies...
  37. pmc Cardiovascular drug trials: how to examine interaction, and why so
    T J Cleophas
    European Interuniversity College of Pharmaceutical Medicine, for the EC Socrates Project, Claude Bernard University, Lyon, France and Department of Internal Medicine, Albert Schweitzer Hospital, Dordrecht, The Netherlands
    Neth Heart J 15:61-6. 2007
    ..This is due to multiple uncontrolled factors that co-determine the efficacy of the new treatment. In statistical terms, they interact with the new treatment. Interaction effects are rarely assessed in cardiovascular trials...
  38. doi Clinical trials: odds ratios and multiple regression models--why and how to assess them
    Mohamad Sobh
    European College of Pharmaceutical Medicine, Lyon France
    Am J Ther 15:44-52. 2008
    ..We do hope that this article will stimulate clinical investigators to use ORs and multiple regression models more often...
  39. ncbi The sense and nonsense of regression modeling for increasing precision of clinical trials
    Ton J Cleophas
    Clin Pharmacol Ther 74:295-7. 2003