Early Risk Stratification of Dosing Errors in Clinical Trials Using Machine Learning
Organizations: Department of Radiology and Medical Informatics, University of Geneva, Geneva, Switzerland · Actelion Pharmaceuticals Ltd, Basel, Switzerland
Abstract
Objective: The objective of this study is to develop a machine learning (ML)-based framework for early risk stratification of clinical trials (CTs) according to their likelihood of exhibiting a high rate of dosing errors, using information available prior to trial initiation. Materials and Methods: We constructed a dataset from ClinicalTrials.gov comprising 42,112 CTs. Structured, semi-structured trial data, and unstructured protocol-related free-text data were extracted. CTs were assigned binary labels indicating elevated dosing error rate, derived from adverse event reports, MedDRA terminology, and Wilson confidence intervals. We evaluated an XGBoost model trained on structured features, a ClinicalModernBERT model using textual data, and a simple late-fusion model combining both modalities. Post-hoc probability calibration was applied to enable interpretable, trial-level risk stratification. Results: The late-fusion model achieved the highest AUC-ROC (0.862). Beyond discrimination, calibrated outputs enabled robust stratification of CTs into predefined risk categories. The proportion of trials labeled as having an excessively high dosing error rate increased monotonically across higher predicted risk groups and aligned with the corresponding predicted probability ranges. Discussion: These findings indicate that dosing error risk can be anticipated at the trial level using pre-initiation information. Probability calibration was essential for translating model outputs into reliable and interpretable risk categories, while simple multimodal integration yielded performance gains without requiring complex architectures. Conclusion: This study introduces a reproducible and scalable ML framework for early, trial-level risk stratification of CTs at risk of high dosing error rates, supporting proactive, risk-based quality management in clinical research.
Figures & tables
| Categorical and binary features | ||||
| Feature name | Data type | Missing (%) | Most frequent class (%) | Description |
| primaryPurpose | Categorical | 0.94 | Treatment (84) | Primary objective of the study |
| masking | Categorical | 0.18 | None (52) | Masking strategy used in the trial design |
| sex | Categorical | 0.02 | All (88) | Sex eligibility criteria for participants |
| phases | Categorical (multi-label) | 0.01 | Phase II (41) | Clinical development phase(s) of the trial |
| armGroupTypes | Categorical (multi-label) | 0.60 | Experimental (64) | Type(s) of study arms |
| Model | AUC | Brier | F1 | F1 (macro) | Rec | Prec | BalAcc | Acc |
|---|---|---|---|---|---|---|---|---|
| XGBoost (uncal.) | 0.848 | 0.105 | 0.293 | 0.619 | 0.423 | 0.224 | 0.674 | 0.900 |
| XGBoost | 0.848 | 0.042 | 0.292 | 0.619 | 0.423 | 0.222 | 0.674 | 0.899 |
| ClinicalModernBERT (uncal.) | 0.855 | 0.092 | 0.304 | 0.626 | 0.429 | 0.235 | 0.678 | 0.903 |
| ClinicalModernBERT | 0.855 | 0.042 | 0.306 | 0.628 | 0.426 | 0.239 | 0.678 | 0.905 |
| LateFusion (uncal.) | 0.862 | 0.090 | 0.300 | 0.633 | 0.284 | 0.318 | 0.626 | 0.935 |
| LateFusion | 0.862 | 0.041 | 0.298 | 0.632 | 0.281 | 0.319 | 0.625 | 0.935 |
| Risk group | Number of CTs | Number of events | Event rate (%) | Relative risk |
| LateFusion (uncal.) | ||||
| Low | 401 | 0 | 0.00 | 0.000 |
| Moderate | 1773 | 6 | 0.34 | 0.069 |
| High | 953 | 8 | 0.84 | 0.171 |
| Very high | 3191 | 296 | 9.28 | 1.89 |
| LateFusion | ||||
| Risk group | Number of CTs | Number of events | Event rate (%) | Relative risk |
| Early stage | ||||
| Low | 642 | 3 | 0.47 | 0.235 |
| Moderate | 75 | 1 | 1.33 | 0.672 |
| High | 50 | 5 | 10.00 | 5.038 |
| Very high | 39 | 7 | 17.95 | 9.042 |
| Mid stage | ||||
Appendix figures & tables5 assets
Supplementary material from the paper’s appendix.
Appendix
| Feature | ID | Meaning |
| phases | 0 | NA (not reported) |
| 1 | EARLY_PHASE1 | |
| 2 | PHASE1 | |
| 3 | PHASE2 | |
| 4 | PHASE3 | |
| 5 | PHASE4 |
| Name | Data type / encoding | Description |
|---|---|---|
| overallStatus | Categorical | Overall recruitment status of the trial |
| leadSponsorClass | Categorical | Sponsor class |
| hasProtocol | Binary indicator | Indicates whether a protocol document is available |
| hasSap | Binary indicator | Indicates whether a statistical analysis plan document is available |
| hasIcf | Binary indicator | Indicates whether an informed consent form document is available |
| startDate | Date | Trial initiation date |
| Hyperparameter | Search range | Description |
|---|---|---|
| n_estimators | 100 – 1000 | Number of boosting trees |
| max_depth | 3 – 12 | Maximum depth of individual decision trees |
| learning_rate | Learning rate controlling the contribution of each tree; sampled on a logarithmic scale | |
| subsample | 0.5 – 1.0 | Fraction of training samples randomly subsampled for each tree |
| colsample_bytree | 0.5 – 1.0 | Fraction of features randomly subsampled for each tree |
| gamma | 0 – 5 | Minimum loss reduction required to make a further partition on a leaf node |
| Number of CTs | Number of events | Event rate (%) | Relative risk | |
| XGBoost (uncal.) | ||||
| Low | 79 | 0 | 0.00 | 0.000 |
| Moderate | 1311 | 1 | 0.08 | 0.015 |
| High | 1252 | 8 | 0.64 | 0.130 |
| Very high | 3676 | 301 | 8.19 | 1.669 |
| XGBoost | ||||
| Risk group | Number of CTs | Number of events | Event rate (%) | Relative risk |
| Enrollment 50 | ||||
| Low | 2535 | 16 | 0.63 | 0.517 |
| Moderate | 328 | 5 | 1.52 | 1.248 |
| High | 124 | 8 | 6.45 | 5.283 |
| Very high | 43 | 8 | 18.60 | 15.236 |
| Enrollment 51–200 | ||||