Jiayi (Jessie) Tong

PI of Tong Lab

I am an assistant professor in the Department of Biostatistics at the Johns Hopkins Bloomberg School of Public Health, with an affiliated appointment in the Division of Biomedical Informatics and Data Science at the Johns Hopkins School of Medicine. I am also a core faculty member of the Hopkins Business of Health Initiative and a faculty member of the Johns Hopkins Data Science and AI Institute. I completed my Ph.D. at the Department of Biostatistics, Epidemiology and Informatics at Perelman School of Medicine at the University of Pennsylvania, where I was fortunate to be advised by Dr. Yong Chen. Previously, I received a B.S. with High Honors in Applied Mathematics from the University of California, San Diego in 2017.

Jiayi (Jessie) Tong

Research

With an overall theme of clinical evidence generation and evidence synthesis with real-world data (RWD), my research interests span:

Federated learning across health systems

Privacy-preserving distributed algorithms that combine evidence across hospitals and research networks without sharing patient-level data.

Bias correction for error-prone EHR data

Methods that use surrogate and algorithm-derived phenotypes to reduce bias from misclassified outcomes in EHR-based studies.

Evidence synthesis and meta-research

Methods for more timely and reliable systematic reviews and meta-analyses, covering preprints, publication bias, and fragility.

News

  • Presented “An alternative method for assessing the fragility of survival analysis results” at the ASA Biopharmaceutical Section Regulatory–Industry Statistics Workshop.
  • Presented “Unlocking Multi-Institutional Insights into Disease Progression Using Federated Learning on Longitudinal Electronic Health Records” at JSM 2026.
  • "PDA in action: ten principles for high-quality multi-site clinical evidence generation" published in JAMIA.
  • PEAL, a lossless one-shot federated learning method for studying disease progression across institutions, published in npj Digital Medicine.
  • Presented “Federated Learning Algorithms with EHR Data: Generating Clinical Evidence from Multi-site Real-world Longitudinal Data” at the 2026 ICSA Applied Statistics Symposium.
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  • Received the Ralph E. Powe Junior Faculty Enhancement Award (ORAU).
  • Received a 2026 IMS New Researcher Travel Award.
  • Presented “Advancing Timely and Reliable Evidence Synthesis in Rapidly Evolving Research Areas through the Inclusion of Preprints” at ENAR 2026.
  • Presented “Advancing Timely and Reliable Evidence Synthesis in Rapidly Evolving Research Areas through the Inclusion of Preprints” at CFE-CMStatistics 2025.
  • Presented “Statistical Innovations Using Real World Data for Health System Performance Assessment with Perspectives on AI” at the 2025 IQVIA Institute Research Forum.
  • Presented “Unlocking Efficiency in Real-world Collaborative Studies: A Multi-site International Study with COLA-GLMM” at the 2025 IMS New Researchers Conference.
  • Joined the Johns Hopkins Data Science and AI Institute as a faculty member.
  • Two papers published: risk of neuropsychiatric conditions after SARS-CoV-2 infection, in Nature Communications; and the one-shot lossless GLMM algorithm, in npj Digital Medicine.
  • Affiliated appointment in the Division of Biomedical Informatics and Data Science, JHU School of Medicine.
  • Presented “Unlocking Efficiency in Real-world Collaborative Studies: A Multi-site International Study with COLA-GLMM” at ENAR 2025.
  • Presented “Statistical Innovations Using Real World Data for Health System Performance Assessment” at “Unlocking Insights from Electronic Health Record Data with Statistics and AI” at Brown University.
  • Presented “A One-shot and Lossless Federated Generalized Linear Mixed Effect Model” at the 2024 OHDSI Global Symposium.
  • Became a core faculty member of the Hopkins Business of Health Initiative.
  • Joined the Department of Biostatistics at Johns Hopkins Bloomberg School of Public Health as an Assistant Professor (announcement).
  • Completed my PhD in Biostatistics at the University of Pennsylvania.

Publications

* Equal contribution

PDA (Privacy-Preserving Distributed Algorithms) in action: ten principles for high-quality multi-site clinical evidence generation

Yong Chen*, Jiayi Tong*, Yiwen Lu*, Rui Duan, Chongliang Luo, Marc A. Suchard, Patrick B. Ryan, Andrew E. Williams, John H. Holmes, Jason H. Moore, Hua Xu, Yun Lu, Raymond J. Carroll, Scott L. Zeger, George Hripcsak, Martijn J. Schuemie
Journal of the American Medical Informatics Association (JAMIA), 2026

Sets out 10 best-practice principles for multi-site studies that use privacy-preserving distributed algorithms (PDA), from study preparation and protocol development to analysis and reporting.

Incorporating preprints in systematic reviews: a preliminary study of a novel method for rapid evidence synthesis

Jiayi Tong, Yifei Sun, Rebecca A. Hubbard, M. Elle Saine, Hua Xu, Xu Zuo, Lifeng Lin, Chunhua Weng, Christopher H. Schmid, Stephen E. Kimmel, Craig A. Umscheid, Adam Cuker, Yong Chen
Journal of the American Medical Informatics Association (JAMIA), 2025

A two-stage method for including preprints in meta-analyses: weight them by a confidence score, then adjust for publication or reporting bias; shown on two COVID-19 treatments.

Risk of neuropsychiatric and related conditions associated with SARS-CoV-2 infection: a difference-in-differences analysis

Yiwen Lu*, Jiayi Tong*, Dazheng Zhang*, Jiajie Chen, Lu Li, Yuqing Lei, Ting Zhou, Leyna V. Aragon, Michael J. Becich, Saul Blecker, Nathan J. Blum, Dimitri A. Christakis, Mady Hornig, Maxwell M. Hornig-Rohan, Ravi Jhaveri, W. Schuyler Jones, Amber Brown Keebler, Kelly Kelleher, Susan Kim, Abu Saleh Mohammad Mosa, Kathleen Pajer, Jonathan Platt, Hayden T. Schwenk, Bradley W. Taylor, Levon H. Utidjian, David A. Williams, Raghuram Prasad, Josephine Elia, Christopher B. Forrest, Yong Chen
Nature Communications, 2025

In EHR data from 25 RECOVER institutions, children and youths with SARS-CoV-2 infection had higher risks of neuropsychiatric conditions, including anxiety, than matched COVID-19-negative peers.

Unlocking efficiency in real-world collaborative studies: a multi-site international study with one-shot lossless GLMM algorithm

Jiayi Tong, Jenna M. Reps, Chongliang Luo, Yiwen Lu, Lu Li, Juan Manuel Ramirez-Anguita, Milou T. Brand, Scott L. DuVall, Thomas Falconer, Alex Mayer Fuentes, Xing He, Michael E. Matheny, Miguel A. Mayer, Bhavnisha K. Patel, Katherine R. Simon, Marc A. Suchard, Guojun Tang, Benjamin Viernes, Ross D. Williams, Mui van Zandt, Fei Wang, Jiang Bian, Jiayu Zhou, David A. Asch, Yong Chen
npj Digital Medicine, 2025

COLA-GLMM fits generalized linear mixed models across sites in one communication round without loss of accuracy; validated on eight international databases for COVID-19 mortality risk factors.

Advancing Interpretable Regression Analysis for Binary Data: A Novel Distributed Algorithm Approach

Jiayi Tong*, Lu Li*, Jenna Marie Reps, Vitaly Lorman, Naimin Jing, Mackenzie Edmondson, Xiwei Lou, Ravi Jhaveri, Kelly J. Kelleher, Nathan M. Pajor, Christopher B. Forrest, Jiang Bian, Haitao Chu, Yong Chen
Statistics in Medicine, 2024

ODAP-B, a one-shot distributed algorithm for relative risks of rare binary outcomes, gives less biased estimates than two-step meta-analysis, shown with data from eight medical centers.

Evaluating site-of-care-related racial disparities in kidney graft failure using a novel federated learning framework

Jiayi Tong, Yishan Shen, Alice Xu, Xing He, Chongliang Luo, Mackenzie Edmondson, Dazheng Zhang, Yiwen Lu, Chao Yan, Ruowang Li, Lianne Siegel, Lichao Sun, Elizabeth A. Shenkman, Sally C. Morton, Bradley A. Malin, Jiang Bian, David A. Asch, Yong Chen
Journal of the American Medical Informatics Association (JAMIA), 2024

A federated framework with counterfactual modeling that assesses how site of care contributes to racial disparities in kidney graft failure across 73 U.S. transplant centers.

Confidence score: a data-driven measure for inclusive systematic reviews considering unpublished preprints

Jiayi Tong, Chongliang Luo, Yifei Sun, Rui Duan, M. Elle Saine, Lifeng Lin, Yifan Peng, Yiwen Lu, Anchita Batra, Anni Pan, Olivia Wang, Ruowang Li, Arielle Marks-Anglin, Yuchen Yang, Xu Zuo, Yulun Liu, Jiang Bian, Stephen E. Kimmel, Keith Hamilton, Adam Cuker, Rebecca A. Hubbard, Hua Xu, Yong Chen
Journal of the American Medical Informatics Association (JAMIA), 2024

A data-driven "confidence score," estimated with a survival cure model, for weighting preprints in systematic reviews and meta-analyses; validated on 146 COVID-19 therapeutics preprints.

Real-World Effectiveness of BNT162b2 Against Infection and Severe Diseases in Children and Adolescents

Qiong Wu*, Jiayi Tong*, Bingyu Zhang, Dazheng Zhang, Jiajie Chen, Yuqing Lei, Yiwen Lu, Yudong Wang, Lu Li, Yishan Shen, Jie Xu, L. Charles Bailey, Jiang Bian, Dimitri A. Christakis, Megan L. Fitzgerald, Kathryn Hirabayashi, Ravi Jhaveri, Alka Khaitan, Tianchen Lyu, Suchitra Rao, Hanieh Razzaghi, Hayden T. Schwenk, Fei Wang, Margot I. Gage Witvliet, Eric J. Tchetgen Tchetgen, Jeffrey S. Morris, Christopher B. Forrest, Yong Chen
Annals of Internal Medicine, 2024

Estimates the real-world effectiveness of the BNT162b2 vaccine against infection and severe disease in children and adolescents in PEDSnet during the Delta and Omicron periods.

Quantifying and correcting bias due to outcome dependent self-reported weights in longitudinal study of weight loss interventions

Jiayi Tong, Rui Duan, Ruowang Li, Chongliang Luo, Jason H. Moore, Jingsan Zhu, Gary D. Foster, Kevin G. Volpp, William S. Yancy Jr., Pamela A. Shaw, Yong Chen
Scientific Reports, 2023

A framework to detect self-reported weights that are missing not at random and correct the resulting bias, applied to the Keep It Off trial of financial incentives for weight-loss maintenance.

Identifying Clinical Risk Factors for Opioid Use Disorder using a Distributed Algorithm to Combine Real-World Data from a Large Clinical Data Research Network

Jiayi Tong*, Zhaoyi Chen*, Rui Duan*, Wei-Hsuan Lo-Ciganic, Tianchen Lyu, Cui Tao, Peter A. Merkel, Henry R. Kranzler, Jiang Bian, Yong Chen
American Medical Informatics Association (AMIA) Annual Symposium Proceedings, 2020

Applies the one-shot distributed algorithm ODAL to OneFlorida data to identify risk factors for opioid use disorder, with better estimates than meta-analysis.

Honors & Awards

Teaching

  • Instructor, 140.669: Leveraging Electronic Health Records (EHR) Data: Opportunities and Challenges for Evidence Generation, Johns Hopkins Bloomberg School of Public Health, Summer 2025, 2026
  • Instructor, 140.850: Introduction to Statistical Analysis and Evidence Generation with Electronic Health Records (EHR) Data, Johns Hopkins Bloomberg School of Public Health, Spring 2025, 2026