K J M Janssen

Summary

Affiliation: University Medical Center Utrecht
Country: The Netherlands

Publications

  1. ncbi Updating methods improved the performance of a clinical prediction model in new patients
    K J M Janssen
    Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands
    J Clin Epidemiol 61:76-86. 2008
  2. doi Optimisation of the diagnostic strategy for suspected deep-vein thrombosis in primary care
    Kristel J M Janssen
    Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands
    Thromb Haemost 105:154-60. 2011
  3. doi The risk of severe postoperative pain: modification and validation of a clinical prediction rule
    Kristel J M Janssen
    Julius Center for Health Sciences and Primary Care, Department of Anesthesiology, University Medical Center Utrecht, PO Box 85500, 3508 GA Utrecht, The Netherlands
    Anesth Analg 107:1330-9. 2008
  4. doi A simple method to adjust clinical prediction models to local circumstances
    Kristel J M Janssen
    Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Str 6 131, P O Box 85500, 3508 GA Utrecht, The Netherlands
    Can J Anaesth 56:194-201. 2009
  5. doi Dealing with missing predictor values when applying clinical prediction models
    Kristel J M Janssen
    Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, The Netherlands
    Clin Chem 55:994-1001. 2009
  6. doi Missing covariate data in medical research: to impute is better than to ignore
    Kristel J M Janssen
    Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands
    J Clin Epidemiol 63:721-7. 2010
  7. doi Validation, updating and impact of clinical prediction rules: a review
    D B Toll
    Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands
    J Clin Epidemiol 61:1085-94. 2008
  8. doi Correcting for partial verification bias: a comparison of methods
    Joris A H de Groot
    Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, The Netherlands
    Ann Epidemiol 21:139-48. 2011
  9. doi Unpredictable bias when using the missing indicator method or complete case analysis for missing confounder values: an empirical example
    Mirjam J Knol
    Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Str 6 131, PO Box 85500, 3508 GA Utrecht, The Netherlands
    J Clin Epidemiol 63:728-36. 2010
  10. doi Prediction rule for cardiovascular events and mortality in peripheral arterial disease patients: data from the prospective Second Manifestations of ARTerial disease (SMART) cohort study
    Ralf W Sprengers
    Department of Vascular Surgery, University Medical Center Utrecht, Utrecht, The Netherlands
    J Vasc Surg 50:1369-76. 2009

Detail Information

Publications17

  1. ncbi Updating methods improved the performance of a clinical prediction model in new patients
    K J M Janssen
    Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands
    J Clin Epidemiol 61:76-86. 2008
    ..Recently, methods to update existing prediction models with the data of new patients have been proposed. We used an existing model that preoperatively predicts the risk of severe postoperative pain (SPP) to compare five updating methods...
  2. doi Optimisation of the diagnostic strategy for suspected deep-vein thrombosis in primary care
    Kristel J M Janssen
    Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands
    Thromb Haemost 105:154-60. 2011
    ..This suggests that the original diagnostic score can be used to safely exclude clinically suspected DVT in primary care...
  3. doi The risk of severe postoperative pain: modification and validation of a clinical prediction rule
    Kristel J M Janssen
    Julius Center for Health Sciences and Primary Care, Department of Anesthesiology, University Medical Center Utrecht, PO Box 85500, 3508 GA Utrecht, The Netherlands
    Anesth Analg 107:1330-9. 2008
    ..Subsequently, we prospectively tested the modified rule in patients who underwent surgery later in time and in another hospital (external validation)...
  4. doi A simple method to adjust clinical prediction models to local circumstances
    Kristel J M Janssen
    Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Str 6 131, P O Box 85500, 3508 GA Utrecht, The Netherlands
    Can J Anaesth 56:194-201. 2009
    ..However, the model can be adjusted (updated) using the new data. The updated model is then based on both the development and validation data. We show how a simple updating method may suffice to update a clinical prediction model...
  5. doi Dealing with missing predictor values when applying clinical prediction models
    Kristel J M Janssen
    Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, The Netherlands
    Clin Chem 55:994-1001. 2009
    ..In the event that test results (predictor) are unavailable, a strategy is needed to help users applying a prediction model to deal with such missing values. We evaluated 6 strategies to deal with missing values...
  6. doi Missing covariate data in medical research: to impute is better than to ignore
    Kristel J M Janssen
    Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands
    J Clin Epidemiol 63:721-7. 2010
    ..We compared popular methods to handle missing data with multiple imputation (a more sophisticated method that preserves data)...
  7. doi Validation, updating and impact of clinical prediction rules: a review
    D B Toll
    Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands
    J Clin Epidemiol 61:1085-94. 2008
    ..These steps include validity assessment, updating (if necessary), and impact assessment of clinical prediction rules...
  8. doi Correcting for partial verification bias: a comparison of methods
    Joris A H de Groot
    Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, The Netherlands
    Ann Epidemiol 21:139-48. 2011
    ..The authors studied the performance of multiple imputation and the conventional correction method proposed by Begg and Greenes under a range of different situations of partial verification...
  9. doi Unpredictable bias when using the missing indicator method or complete case analysis for missing confounder values: an empirical example
    Mirjam J Knol
    Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Str 6 131, PO Box 85500, 3508 GA Utrecht, The Netherlands
    J Clin Epidemiol 63:728-36. 2010
    ..Using empirical data, we demonstrated the degree and direction of bias in the effect estimate when using these methods compared with multiple imputation (MI)...
  10. doi Prediction rule for cardiovascular events and mortality in peripheral arterial disease patients: data from the prospective Second Manifestations of ARTerial disease (SMART) cohort study
    Ralf W Sprengers
    Department of Vascular Surgery, University Medical Center Utrecht, Utrecht, The Netherlands
    J Vasc Surg 50:1369-76. 2009
    ..Stratifying PAD patients according to their risk of secondary events could aid in achieving optimal therapy compliance. To this end we developed a prediction model for secondary cardiovascular events in PAD patients...
  11. doi The Glasgow Aneurysm Score as a tool to predict 30-day and 2-year mortality in the patients from the Dutch Randomized Endovascular Aneurysm Management trial
    Annette F Baas
    Julius Center Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands
    J Vasc Surg 47:277-81. 2008
    ..Here, we applied the GAS to patients from the Dutch Randomized Endovascular Aneurysm Repair (DREAM) trial and compared the applicability of the GAS between open repair and EVAR...
  12. doi Adjusting for differential-verification bias in diagnostic-accuracy studies: a Bayesian approach
    Joris A H de Groot
    Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands
    Epidemiology 22:234-41. 2011
    ..We illustrate this approach using data from a study on the accuracy of the elbow extension test for diagnosis of elbow fractures in patients with elbow injury, using either radiography or follow-up as reference standards...
  13. doi Multiple imputation to correct for partial verification bias revisited
    J A H de Groot
    Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands
    Stat Med 27:5880-9. 2008
    ..Additional research is needed to better understand which correction methods should be preferred in more complex scenarios of missing reference test outcome in diagnostic research...
  14. doi Systematic review: diagnostic accuracy of clinical decision rules for venous thromboembolism in elderly
    R N Siccama
    Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, The Netherlands
    Ageing Res Rev 10:304-13. 2011
    ..Clinical decision rules (CDRs) have been developed and implemented for VTE. Yet, until now, no study has evaluated the existing evidence of the diagnostic accuracy of CDRs for VTE in elderly...
  15. doi Prediction model for hypertension in pregnancy in nulliparous women using information obtained at the first antenatal visit
    Marie Elise Nijdam
    Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands
    J Hypertens 28:119-26. 2010
    ..To develop a prediction model for the occurrence of hypertension in pregnancy using clinical variables obtained routinely at the antenatal booking visit prior to 16 weeks gestation...
  16. pmc Excluding venous thromboembolism using point of care D-dimer tests in outpatients: a diagnostic meta-analysis
    G J Geersing
    Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands
    BMJ 339:b2990. 2009
    ..To review the evidence on the diagnostic accuracy of the currently available point of care D-dimer tests for excluding venous thromboembolism...
  17. doi Diagnostic accuracy and user-friendliness of 5 point-of-care D-dimer tests for the exclusion of deep vein thrombosis
    Geert Jan Geersing
    University Medical Center Utrecht, Utrecht, The Netherlands
    Clin Chem 56:1758-66. 2010
    ..Before implementation in practice, however, the diagnostic accuracy of each test should be validated...