P Royston

Summary

Affiliation: National Institute for Medical Research
Country: UK

Publications

  1. pmc Combining estimates of interest in prognostic modelling studies after multiple imputation: current practice and guidelines
    Andrea Marshall
    Centre for Statistics in Medicine, University of Oxford, Oxford, UK
    BMC Med Res Methodol 9:57. 2009
  2. pmc Comparison of techniques for handling missing covariate data within prognostic modelling studies: a simulation study
    Andrea Marshall
    Centre for Statistics in Medicine, University of Oxford, Oxford, UK
    BMC Med Res Methodol 10:7. 2010
  3. ncbi 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
  4. ncbi Construction and validation of a prognostic model across several studies, with an application in superficial bladder cancer
    Patrick Royston
    Cancer Division, MRC Clinical Trials Unit, 222 Euston Road, London NW1 2DA, U K
    Stat Med 23:907-26. 2004
  5. ncbi Novel designs for multi-arm clinical trials with survival outcomes with an application in ovarian cancer
    Patrick Royston
    Cancer Division, MRC Clinical Trials Unit, 222 Euston Road, London NW1 2DA, UK
    Stat Med 22:2239-56. 2003
  6. ncbi 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
  7. ncbi Flexible parametric proportional-hazards and proportional-odds models for censored survival data, with application to prognostic modelling and estimation of treatment effects
    Patrick Royston
    Cancer Division, MRC Clinical Trials Unit, 222 Euston Road, London NW1 2DA, UK
    Stat Med 21:2175-97. 2002
  8. ncbi Building multivariable regression models with continuous covariates in clinical epidemiology--with an emphasis on fractional polynomials
    P Royston
    Cancer Division, MRC Clinical Trials Unit, London, UK
    Methods Inf Med 44:561-71. 2005
  9. ncbi Goodness-of-fit statistics for age-specific reference intervals
    P Royston
    Department of Medical Statistics and Evaluation, Imperial College School of Medicine Hammersmith Campus, Du Cane Road, London W12 0NN, U K
    Stat Med 19:2943-62. 2000
  10. ncbi 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

Collaborators

Detail Information

Publications38

  1. pmc Combining estimates of interest in prognostic modelling studies after multiple imputation: current practice and guidelines
    Andrea Marshall
    Centre for Statistics in Medicine, University of Oxford, Oxford, UK
    BMC Med Res Methodol 9:57. 2009
    ..However, the normality assumption may not be appropriate for all the parameters of interest when analysing prognostic modelling studies, such as predicted survival probabilities and model performance measures...
  2. pmc Comparison of techniques for handling missing covariate data within prognostic modelling studies: a simulation study
    Andrea Marshall
    Centre for Statistics in Medicine, University of Oxford, Oxford, UK
    BMC Med Res Methodol 10:7. 2010
    ..Therefore a simulation study was performed to assess the effects of different missing data techniques on the performance of a prognostic model...
  3. ncbi 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...
  4. ncbi Construction and validation of a prognostic model across several studies, with an application in superficial bladder cancer
    Patrick Royston
    Cancer Division, MRC Clinical Trials Unit, 222 Euston Road, London NW1 2DA, U K
    Stat Med 23:907-26. 2004
    ....
  5. ncbi Novel designs for multi-arm clinical trials with survival outcomes with an application in ovarian cancer
    Patrick Royston
    Cancer Division, MRC Clinical Trials Unit, 222 Euston Road, London NW1 2DA, UK
    Stat Med 22:2239-56. 2003
    ..The intermediate outcome measure is progression-free survival. An international randomized controlled trial using the new design is already under way...
  6. ncbi 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...
  7. ncbi Flexible parametric proportional-hazards and proportional-odds models for censored survival data, with application to prognostic modelling and estimation of treatment effects
    Patrick Royston
    Cancer Division, MRC Clinical Trials Unit, 222 Euston Road, London NW1 2DA, UK
    Stat Med 21:2175-97. 2002
    ..The tools described here may be a step towards providing greater insight into the natural history of the disease and into possible underlying causes of clinical events. We illustrate these aspects by using the two examples in cancer...
  8. ncbi Building multivariable regression models with continuous covariates in clinical epidemiology--with an emphasis on fractional polynomials
    P Royston
    Cancer Division, MRC Clinical Trials Unit, London, UK
    Methods Inf Med 44:561-71. 2005
    ....
  9. ncbi Goodness-of-fit statistics for age-specific reference intervals
    P Royston
    Department of Medical Statistics and Evaluation, Imperial College School of Medicine Hammersmith Campus, Du Cane Road, London W12 0NN, U K
    Stat Med 19:2943-62. 2000
    ..For the cases considered the grid tests are always inferior to the Q- and B- tests...
  10. ncbi 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...
  11. ncbi Simplified estimation of age-specific reference intervals for skewed data
    E M Wright
    Department of Medical Statistics and Evaluation, Imperial College School of Medicine, London, U K
    Stat Med 16:2785-803. 1997
    ..The scope of the method is illustrated by fitting models to several real data sets and assessing each model using goodness-of-fit techniques...
  12. pmc How do multi-stage, multi-arm trials compare to the traditional two-arm parallel group design--a reanalysis of 4 trials
    F M S Barthel
    Department of Biostatistics, Institute of Psychiatry, King s College London, London, UK
    Trials 10:21. 2009
    ..To speed up the evaluation of new therapies, the multi-arm, multi-stage trial design was suggested previously by the authors...
  13. pmc Is treatment with interferon-alpha effective in all patients with metastatic renal carcinoma? A new approach to the investigation of interactions
    P Royston
    Cancer Division, MRC Clinical Trials Unit, 222 Euston Road, London NW1 2DA, UK
    Br J Cancer 90:794-9. 2004
    ..Since our results are derived from flexible statistical models, they may be interpreted as a new hypothesis and require validation in independent data...
  14. ncbi The use of fractional polynomials to model continuous risk variables in epidemiology
    P Royston
    Department of Medical Statistics and Evaluation, Imperial College School of Medicine, London, UK
    Int J Epidemiol 28:964-74. 1999
    ..The traditional method of analysing continuous or ordinal risk factors by categorization or linear models may be improved...
  15. pmc An approach to estimating prognosis using fractional polynomials in metastatic renal carcinoma
    P Royston
    MRC Clinical Trials Unit, Cancer Division, Medical Research Council MRC, London, UK
    Br J Cancer 94:1785-8. 2006
    ..6 months (high risk). Our approach, based on categorising a continuous prognostic index produced by the MFP algorithm, allowed more flexibility in the determination of risk groups than traditional approaches...
  16. doi A simulation study of predictive ability measures in a survival model II: explained randomness and predictive accuracy
    B Choodari-Oskooei
    London Hub for Trials Methodology Research, MRC Clinical Trials Unit, Aviation House, London, WC2B 6NH, UK
    Stat Med 31:2644-59. 2012
    ..The results show that the other measures perform poorly, primarily because they are affected either by the degree of censoring or the follow-up period...
  17. ncbi Stability of multivariable fractional polynomial models with selection of variables and transformations: a bootstrap investigation
    P Royston
    MRC Clinical Trials Unit, 222 Euston Road, London NW1 2DA, U K
    Stat Med 22:639-59. 2003
    ..Despite the considerable flexibility of the family of fractional polynomials and the consequent risk of overfitting when several variables are considered, we conclude that the multivariable selection algorithm can find stable models...
  18. ncbi A new approach to modeling daily probabilities of conception
    P Royston
    Department of Medical Statistics and Evaluation, Imperial College School of Medicine, London, UK
    Biometrics 55:1005-13. 1999
    ..Estimates of the probability of conception during the most fertile period of the cycle and of the effects of covariates are similar to estimates found using standard models...
  19. ncbi Evaluation of sample size and power for multi-arm survival trials allowing for non-uniform accrual, non-proportional hazards, loss to follow-up and cross-over
    F M S Barthel
    MRC Clinical Trials Unit, London, UK
    Stat Med 25:2521-42. 2006
    ..Our investigations suggest that ART is the first software to allow incorporation of all these elements. Further extensions to the methodology such as non-local alternatives for the logrank test are also considered...
  20. ncbi The effect of stopping smoking on cervical Langerhans' cells and lymphocytes
    A Szarewski
    Margaret Pyke Centre, London, UK
    BJOG 108:295-303. 2001
    ....
  21. ncbi Prediction of patient-specific risk of early preterm delivery using maternal history and sonographic measurement of cervical length: a population-based prospective study
    M S To
    Harris Birthright Research Centre for Fetal Medicine, King s College Hospital Medical School, London, UK
    Ultrasound Obstet Gynecol 27:362-7. 2006
    ....
  22. ncbi 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...
  23. ncbi 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...
  24. ncbi Fractional polynomials in a new metastatic renal carcinoma continuous prognostic index involving histology, laboratory, and clinical predictors
    Jens Atzpodien
    Fachklinik Hornheide an der Westfälische Wilhelms Universität Münster, Munster, Germany
    Cancer Biother Radiopharm 22:812-8. 2007
    ..We analyzed the effect of histology and various clinical and laboratory predictors in a new continuous prognostic index for metastatic renal-cell carcinoma based on fractional polynomials...
  25. doi Interactions between treatment and continuous covariates: a step toward individualizing therapy
    Patrick Royston
    J Clin Oncol 26:1397-9. 2008
  26. ncbi 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...
  27. pmc Speeding up the evaluation of new agents in cancer
    Mahesh K B Parmar
    Clinical Trials Unit, London, UK
    J Natl Cancer Inst 100:1204-14. 2008
    ..By using intermediate outcomes and testing a number of new agents (and combinations) simultaneously, the new design requires fewer patients. Three trials using this methodology are presented...
  28. ncbi Visualizing length of survival in time-to-event studies: a complement to Kaplan-Meier plots
    Patrick Royston
    Cancer Group, MRC Clinical Trials Unit, 222 Euston Rd, London NW1 2DA, UK
    J Natl Cancer Inst 100:92-7. 2008
    ..These graphs of the distribution of survival times for individuals in each study group, which are simple to produce, may usefully complement Kaplan-Meier plots...
  29. ncbi Simplifying a prognostic model: a simulation study based on clinical data
    Gareth Ambler
    Department of Statistical Science, University College, 1 19 Torrington Place, London WC1E 7HB, UK
    Stat Med 21:3803-22. 2002
    ..Optimizing the Akaike information criterion appears to be appropriate for choosing the degree of simplification...
  30. ncbi Prognostic model for HIV-1 disease progression in patients starting antiretroviral therapy was validated using independent data
    Margaret May
    Antiretroviral Therapy ART Cohort Collaboration Department of Social Medicine, University of Bristol, Bristol BS8 2PR, UK
    J Clin Epidemiol 58:1033-41. 2005
    ..The objective is to validate the model on independent data from CASCADE...
  31. ncbi Cardiac surgery risk modeling for mortality: a review of current practice and suggestions for improvement
    Rumana Z Omar
    MRC Clinical Trials Unit London, London, United Kingdom
    Ann Thorac Surg 77:2232-7. 2004
    ..Model development and validation processes are not always linked to the clinical aim of the model, which may affect their clinical validity. We make some suggestions in this review for improvement in methodology and reporting...
  32. ncbi Risk stratification for in-hospital mortality in acutely decompensated heart failure
    Patrick Royston
    JAMA 293:2467-8; author reply 2468. 2005
  33. ncbi A comparison of imputation techniques for handling missing predictor values in a risk model with a binary outcome
    Gareth Ambler
    Department of Statistical Science, University College London Joint UCLH UCL Biomedical Research Unit, London, UK
    Stat Methods Med Res 16:277-98. 2007
    ..MICE was amongst the best performing multiple imputation methods with regards to the quality of the predictions. Additionally, it produced the least biased estimates, with good coverage, and hence is recommended for use in practice...
  34. ncbi Development and validation of a prognostic model for survival time data: application to prognosis of HIV positive patients treated with antiretroviral therapy
    Margaret May
    Department of Social Medicine, University of Bristol, Bristol, UK
    Stat Med 23:2375-98. 2004
    ..The methods are illustrated by using a model developed to predict progression to a new AIDS event or death in HIV-1 positive patients starting antiretroviral therapy...
  35. pmc The cost of dichotomising continuous variables
    Douglas G Altman
    Cancer Research UK NHS Centre for Statistics in Medicine, Wolfson College, Oxford OX2 6UD
    BMJ 332:1080. 2006
  36. ncbi Analysis of quality of life data in controlled clinical trials
    Patrick Royston
    Stat Methods Med Res 11:1-2. 2002
  37. ncbi Generic, simple risk stratification model for heart valve surgery
    Gareth Ambler
    Department of Statistical Science, University College, London, UK
    Circulation 112:224-31. 2005
    ..This study aims to develop a simple risk model to predict the risk of in-hospital mortality for patients undergoing heart valve surgery to provide information to patients and clinicians and to facilitate institutional comparisons...
  38. ncbi The design of simulation studies in medical statistics
    Andrea Burton
    Cancer Research UK NHS Centre for Statistics in Medicine, Oxford, UK
    Stat Med 25:4279-92. 2006
    ..A checklist highlighting the important considerations when designing a simulation study is provided. A small review of the literature identifies the current practices within published simulation studies...