Federated Adaptive Causal Estimation (FACE) of Target Treatment Effects

• 成果类型: Article; Early Access
• 署名作者: Han, Larry; Hou, Jue; Cho, Kelly; Duan, Rui; Cai, Tianxi
• 署名单位: Harvard University; Northeastern University; University of Minnesota System; University of Minnesota Twin Cities; US Department of Veterans Affairs; Harvard University; Harvard Medical School
• 刊物名称: JOURNAL OF THE AMERICAN STATISTICAL ASSOCIATION
• ISSN/ISSBN: 0162-1459
• DOI: 10.1080/01621459.2025.2453249
• 发表日期: 2025
• 关键词: communication-efficient; randomized-trial; inferences; selection; models

摘要

Federated learning of causal estimands may greatly improve estimation efficiency by leveraging data from multiple study sites, but robustness to heterogeneity and model misspecifications is vital for ensuring validity. We develop a Federated Adaptive Causal Estimation (FACE) framework to incorporate heterogeneous data from multiple sites to provide treatment effect estimation and inference for a flexibly specified target population of interest. FACE accounts for site-level heterogeneity in the distribution of covariates through density ratio weighting. To safely incorporate source sites and avoid negative transfer, we introduce an adaptive weighting procedure via a penalized regression, which achieves both consistency and optimal efficiency. Our strategy is communication-efficient and privacy-preserving, allowing participating sites to share summary statistics only once with other sites. We conduct both theoretical and numerical evaluations of FACE and apply it to conduct a comparative effectiveness study of BNT162b2 (Pfizer) and mRNA-1273 (Moderna) vaccines on COVID-19 outcomes in U.S. veterans using electronic health records from five VA regional sites. We show that compared to traditional methods, FACE meaningfully increases the precision of treatment effect estimates, with reductions in standard errors ranging from 26% to 67%. Supplementary materials for this article are available online, including a standardized description of the materials available for reproducing the work.