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Informative censoring in externally controlled clinical trials: a potential source of bias
T Rudra Gupta1, D E Schwartz1, R Saha1
1Dana-Farber Cancer Institute, Boston, USA; Harvard School of Public Health, Boston, USA.
ESMO Open
|January 4, 2025
Summary
Informative censoring in external control data can bias cancer clinical trial results, affecting statistical power and error rates. Researchers must account for this bias when using external data in trial designs.
Area of Science:
- Clinical Trials
- Biostatistics
- Cancer Research
Background:
- External data use in cancer clinical trials is common but can introduce bias.
- Informative censoring, a statistical dependence between censoring and survival times, is an often-overlooked bias source.
Purpose of the Study:
- To investigate the impact of informative censoring of external controls on cancer clinical trial outcomes.
- To evaluate how informative censoring affects bias, type I error, and power in simulated cancer trials.
Main Methods:
- Simulations of single-arm and randomized controlled cancer clinical trials.
- Inclusion of model-based replicates and in silico glioblastoma trials.
- Modeling of informative censoring with positive or negative associations between censoring and survival times.
Main Results:
- Informative censoring of external control data demonstrably biases cancer clinical trial results.
- The direction and magnitude of bias are dependent on the specific censoring mechanism.
- Informative censoring can lead to inflation or reduction of type I error and statistical power.
Conclusions:
- Clinical trial designs incorporating external data must address the risk of bias from informative censoring.
- Analyses to detect informative censoring are crucial for trials utilizing external control data.
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