Jiajun Liu

Preprint · June 30, 2026 Identifying patients who are likely to benefit from a treatment is central to precision medicine and can guide follow-up trials, enrichment designs, and individualized decisions. Although randomized controlled trials (RCTs) provide evidence on efficacy, th ... Link to item Cite

An Estimand-Focused Approach for AUC Generalization and Cross-Study Benchmarking

Preprint · November 18, 2025 The area under the ROC curve (AUC) is the standard measure of a biomarker's discriminatory accuracy; however, AUC is rarely treated as a population-specific estimand. When validation cohorts differ from the intended target population in case mix, Naïve AUC ... Link to item Cite

Variance Estimation for Weighted Average Treatment Effects

Preprint · August 11, 2025 Common variance estimation methods for weighted average treatment effects (WATEs) in observational studies include nonparametric bootstrap and model-based, closed-form sandwich variance estimation. However, the computational cost of bootstrap increases wit ... Link to item Cite

Robust Estimation and Inference in Hybrid Controlled Trials for Binary Outcomes: A Case Study on Non-Small Cell Lung Cancer

Preprint · April 30, 2025 Hybrid controlled trials (HCTs), which augment randomized controlled trials (RCTs) with external controls (ECs), are increasingly receiving attention as a way to address limited power, slow accrual, and ethical concerns in clinical research. However, borro ... Link to item Cite