Fan Xia, PhD

Assistant Professor
Epidemiology & Biostatistics

Most of my past and current research is oriented around causal mediation analysis. A part of my work provides a comprehensive guide to applied statisticians and epidemiologists that can help them navigate the philosophical subtleties and abundant methodology in causal inference. Another part of my work is to develop methodologies for complex causal mediation structures, including mediation analysis with treatment-induced confounding, mediation analysis with multiple mediation pathways, and mediation analysis for longitudinal data, using rigorous statistical theories for semiparametric inference.
In addition to causal mediation analysis, my research involves causal discovery, which is another important topic in causal inference, and cluster randomized trials with stepped wedge designs, which are related to model-based causal inference with longitudinal data.


Estimated Prevalence and Testing for Albuminuria in US Adults at Risk for Chronic Kidney Disease.

JAMA network open

Chu CD, Xia F, Du Y, Singh R, Tuot DS, Lamprea-Montealegre JA, Gualtieri R, Liao N, Kong SX, Williamson T, Shlipak MG, Estrella MM

Analysis of stepped wedge cluster randomized trials in the presence of a time-varying treatment effect.

Statistics in medicine

Kenny A, Voldal EC, Xia F, Heagerty PJ, Hughes JP

Random effect misspecification in stepped wedge designs.

Clinical trials (London, England)

Voldal EC, Xia F, Kenny A, Heagerty PJ, Hughes JP

Model misspecification in stepped wedge trials: Random effects for time or treatment.

Statistics in medicine

Voldal EC, Xia F, Kenny A, Heagerty PJ, Hughes JP

Elucidating Pathways Mediating the Relationship Between Male Sex and COVID-19 Severity.

Clinical epidemiology

Stalter RM, Atluri V, Xia F, Thomas KK, Lan KF, Greninger AL, Patel RC

swCRTdesign: An RPackage for Stepped Wedge Trial Design and Analysis.

Computer methods and programs in biomedicine

Voldal EC, Hakhu NR, Xia F, Heagerty PJ, Hughes JP

Robust inference for the stepped wedge design.


Hughes JP, Heagerty PJ, Xia F, Ren Y

In what circumstances could nondaily preexposure prophylaxis for HIV substantially reduce program costs?

AIDS (London, England)

Mitchell KM, Dimitrov D, Hughes JP, Xia F, Donnell D, Amico KR, Bokoch K, Chitwarakorn A, Bekker LG, Holtz TH, Mannheimer S, Grant RM, Boily MC

HELOISE: Phase IIIb Randomized Multicenter Study Comparing Standard-of-Care and Higher-Dose Trastuzumab Regimens Combined With Chemotherapy as First-Line Therapy in Patients With Human Epidermal Growth Factor Receptor 2-Positive Metastatic Gastric or Gast

Journal of clinical oncology : official journal of the American Society of Clinical Oncology

Shah MA, Xu RH, Bang YJ, Hoff PM, Liu T, Herráez-Baranda LA, Xia F, Garg A, Shing M, Tabernero J