Missing Values in Clinical Research [EP16]
2 full days, 1 half day
Prof. G. Molenberghs PhD,
Erasmus MC, Rotterdam NL
The Introduction to R course of NIHES*, Biostatistical Methods II: Classical Regression Models (EP03), Courses for the Quantitative Researcher (SC17) and Repeated Measurments (CE08) or equivalent knowledge.
*If you have been registered for the EP16 course, you will be automatically enrolled in the Introduction to R course, a short online course.
Detailed information about this course:
Missing data frequently occur in clinical trials. An important source for missing data are patients who leave the study prematurely, so-called dropouts. Alternatively, intermittent missing data might occur as well.
When patients are evaluated only once under treatment, then the presence of dropouts makes it hard to comply with the intention-to-treat (ITT) principle. However, when repeated measurements are taken then one can make use of the observed portion of the data to retrieve information on dropouts. Generally, commonly used methods to analyse incomplete longitudinal clinical trial data include complete-case (CC) analysis and an analysis using the last observation carried forward (LOCF). However, these methods rest on strong and unverifiable assumptions about the dropout mechanism. Over the last decades, a number of longitudinal data analysis methods have been suggested, providing a valid estimate for, e.g., the treatment effect under less restrictive assumptions.
The assumptions regarding the dropout mechanism have been classified by Rubin and co-workers as: missing completely at random (MCAR), missing at random (MAR) and missing not at random (MNAR). We will review various repeated measurements models and indicate under which missing data mechanism they will provide valid estimates of the treatment effect. Finally, since it is impossible to verify that the dropout mechanism is MAR we argue that, to evaluate the robustness of the conclusion, a sensitivity analysis thereby varying the assumption on the dropout mechanism should become a standard procedure when analyzing the results of a clinical trial.
Gain insight in various repeated measurements models and under which missing data mechanism they will provide valid estimates of the treatment effect.
Reduction on fees
PLEASE NOTE THIS DOES NOT APPLY TO THE RESEARCH MASTERS (120 ECTS)
50% reduction on our fees for participating institutes of NIHES
This 50% reduction is offered to participants appointed at the departments or sections participating in NIHES.
University Medical Center Rotterdam/Erasmus University Rotterdam:
- Department of Epidemiology
- Department of Public Health
- Department of Psychiatry, Section of Medical Psychology and Psychotherapy
- Department of Child and Adolescent Psychiatry/Psychology
- Department of Health Policy and Management
- Department of Medical Informatics
- Department of General Practice
50% reduction on our fees for NIHES affiliated partners
This 50% reduction is offered to participants appointed at the following NIHES affiliated partners:
University Medical Center Rotterdam/Erasmus University Rotterdam, departments of:
- General Paediatrics
- Plastic and Reconstructive Surgery
- Rehabilitation Medicine
Institute of Medical Education Research Rotterdam (iMERR)
Netherlands Cancer Institute/Antoni van Leeuwenhoek Hospital
- Department of Cancer Epidemiology
25% reduction on our fees for partner institutes of NIHES
For participants appointed at the following departments, institutes:
- Departments of Erasmus MC (except the departments mentioned above)
- Addiction Research Institute (IVO)
- Integraal Kankercentrum Zuid (IKZ)
- Pallas Health Research and Consultancy
- Municipal Health Service Amsterdam (GGD Amsterdam)
- Municipal Health Service Rotterdam (GGD Rotterdam)
25% reduction for all (international) PhD students
Please state your tutor’s name and email address on the application form (remarks field).