Fan Xia, PhD
Assistant Professor
Epidemiology & Biostatistics
School of Medicine

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.

• Cigarette smoke-free home adoption attempts among formerly homeless adults living in permanent supportive housing.
  Drug and alcohol dependence reports 2025 Hawes M, Alway J, Chakravarty D, Kushel M, Max W, Xia F, Neyazi N, Vijayaraghavan M
• "Who experiences large model decay and why?" A Hierarchical Framework for Diagnosing Heterogeneous Performance Drift.
  Proceedings of machine learning research 2025 Singh H, Xia F, Gossmann A, Chuang A, Hong JC, Feng J
• Switch to Integrase Strand Transfer Inhibitors During the Menopausal Transition Is Associated With Accelerated Body Composition Change in Women With HIV.
  Clinical infectious diseases : an official publication of the Infectious Diseases Society of America 2025 Abelman RA, Ma Y, Mehta CC, Yang Q, Xia F, Brock JB, Alcaide M, Sharma A, Floris-Moore M, Topper E, Weber KM, Kassaye SG, Gustafson D, Grunfeld C, Lahiri CD, Tien PC
• Championing Hypertension Remote Monitoring for Equity and Dissemination (CHARMED): A multi-site factorial randomized controlled trial protocol.
  Contemporary clinical trials 2025 Lyles CR, Khoong EC, Stern RJ, Abtahi N, Sharma AE, Pletcher MJ, Xia F, Garcia F, Shah ND, Tieu L, Sarkar U, CHARMED consortium
• Tobacco treatment and policies in mental health and substance use treatment facilities in the US.
  Drug and alcohol dependence 2025 Gu D, Xia F, Vijayaraghavan M
• Estimating the effect of pre-exposure prophylaxis in Black men who have sex with men.
  International journal of epidemiology 2024 Meisner A, Xia F, Chan KCG, Mayer K, Wheeler D, Zangeneh S, Donnell D
• The Built Environment, PTSD Symptoms, and Tobacco Use among Permanent Supportive Housing Residents.
  Journal of community health 2024 Hawes MR, Chakravarty D, Xia F, Max W, Kushel M, Vijayaraghavan M
• State Leadership Academies to reduce cigarette smoking among people with behavioral health conditions in the United States.
  Preventive medicine reports 2024 Vijayaraghavan M, Bonniot C, Satterfield J, Clark B, Xia F, Cheng C, Safier J, Pamatmat M, Schroeder SA
• Robust analysis of stepped wedge trials using composite likelihood models.
  Statistics in medicine 2024 Voldal EC, Kenny A, Xia F, Heagerty P, Hughes JP
• Estimated Prevalence and Testing for Albuminuria in US Adults at Risk for Chronic Kidney Disease.
  JAMA network open 2023 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 2022 Kenny A, Voldal EC, Xia F, Heagerty PJ, Hughes JP
• Random effect misspecification in stepped wedge designs.
  Clinical trials (London, England) 2022 Voldal EC, Xia F, Kenny A, Heagerty PJ, Hughes JP
• Defining And Estimating Principal Stratum Specific Natural Mediation Effects With Semi-competing Risks Data
  Statistica Sinica 2022 Fei Gao, Fan Xia, Kwun Chuen Gary Chan
• Decomposition, identification and multiply robust estimation of natural mediation effects with multiple mediators
  Biometrika 2022 Xia, F., Chan, K.C.G.,
• Model misspecification in stepped wedge trials: Random effects for time or treatment.
  Statistics in medicine 2022 Voldal EC, Xia F, Kenny A, Heagerty PJ, Hughes JP
• A Surrogate Measure for Time-Varying Biomarkers in Randomized Clinical Trials
  Mathematics 2022 Zhuang R, Xia F, Wang Y, Chen Y-Q.
• Elucidating Pathways Mediating the Relationship Between Male Sex and COVID-19 Severity.
  Clinical epidemiology 2022 Stalter RM, Atluri V, Xia F, Thomas KK, Lan KF, Greninger AL, Patel RC
• Identification, Semiparametric Efficiency, and Quadruply Robust Estimation in Mediation Analysis with Treatment-Induced Confounding
  Journal of the American Statistical Association 2021 Xia, F., Chan, K.C.G.
• Discussion on "Causal mediation of semicompeting risks" by Yen-Tsung Huang.
  Biometrics 2021 Chan KCG, Gao F, Xia F
• Power and sample size calculation for stepped-wedge designs with discrete outcomes.
  Trials 2021 Xia F, Hughes JP, Voldal EC, Heagerty PJ
• swCRTdesign: An RPackage for Stepped Wedge Trial Design and Analysis.
  Computer methods and programs in biomedicine 2020 Voldal EC, Hakhu NR, Xia F, Heagerty PJ, Hughes JP
• Robust inference for the stepped wedge design.
  Biometrics 2019 Hughes JP, Heagerty PJ, Xia F, Ren Y
• In what circumstances could nondaily preexposure prophylaxis for HIV substantially reduce program costs?
  AIDS (London, England) 2018 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 Gastroesophageal Junction Adenocarcinoma.
  Journal of clinical oncology : official journal of the American Society of Clinical Oncology 2017 Shah MA, Xu RH, Bang YJ, Hoff PM, Liu T, Herráez-Baranda LA, Xia F, Garg A, Shing M, Tabernero J