Context
Analyzed Phase II clinical trial data for an MDD drug at a pre-IPO biotech company. Objective: use ML and statistical methods to identify potential gaps, latent signals, or patterns not captured by traditional analyses. I had no prior experience in clinical trials or biostatistics.
Constraints: small trial size, limited data points, high noise, and significant placebo effects—conditions that are common in psychiatric trials and fundamentally limit what ML can detect.
Action
Domain ramp-up: Navigated extensive clinical trial documentation, unfamiliar terminology, trial protocols, and outcome measures. Synthesized enough context to work effectively within weeks.
Exploratory analysis: Conducted deep EDA—placebo response patterns, subgroup analyses, outcome distribution shifts. Compared findings against traditional statistical outputs to evaluate where additional methods might add signal versus noise.
ML experimentation: Trained multiple classification models to explore whether ML could surface patterns missed by standard analyses. XGBoost performed best among the models tested. However, accuracy and precision were unstable across folds; performance was insufficient for any production or decision-support use. Made a deliberate judgment that these results should not be over-interpreted or presented as actionable.
Lessons
- Knowing when ML doesn't apply is part of the job. Small, noisy clinical datasets often lack the statistical power for ML to add value. Recognizing this early prevents wasted effort and misleading conclusions.
- EDA and domain understanding matter more than model complexity. The most useful insights came from careful exploratory analysis, not from algorithmic sophistication.
- Negative results are still results. Concluding that ML was not appropriate for this dataset was the correct scientific judgment—not a failure.
- Unfamiliar domains become navigable quickly with focused reading. Clinical trial structure, terminology, and conventions are learnable; the key is knowing what to prioritize.