Guofen Yan, Ph.D.

Assistant Professr
Biostatistics & Epidemiology
Ph.D., Statistics, 2003, Case Western Reserve University

P.O. Box 800717
Tel: 1-434-982-6422
Fax: 1-434-243-5787
Email: guofen.yan@virginia.edu
OMS Room 3887

Expertise:

Specialty Areas Applied to Medical Studies

Design and analysis of Phase III clinical trials;

Linear mixed-effects models for longitudinal data, including joint modeling of longitudinal and cross-sectional associations between clinical markers;

Survival data analysis: recurrent events using counting process, Cox time-dependent regression, Cox regression models incorporating nonparametric smoothing splines, and over-dispersed Poisson regression models;

Nonparametric regression and nonparametric density estimation.

Research Interests:

Bayesian methodology; meta-analysis; longitudinal data analysis; multilevel (hierarchical) models.

Dr. Guofen Yan has been in the Division of Biostatistics and Epidemiology since Fall 2005. Before joining UVA, she had worked in the Department of Quantitative Health Sciences (formerly Department of Biostatistics and Epidemiology) at the Cleveland Clinic Foundation (CCF) for many years. There she collaborated closely with nephrologists in kidney and dialysis-related studies, and had been a primary statistician for several large-scale clinical trials for which CCF served as a Data Coordinating Center, including the Hemodialysis Study (HEMO), the NIH-funded full-scale randomized multi-center clinical trial. Dr. Yan's interests are in both methodological and collaborative research, including design and analysis of phase III clinical trials, longitudinal data analysis, meta-analysis, multilevel modeling, and Bayesian parametric and semi-parametric methods for clinical studies.

Other Information:

Selected Recent Invited Talks/Presentations

Review and Evaluation of Bayesian Diagnostic Techniques for Hierarchical Models, Statistical Engineering Division, National Institute of Standards and Technology, United States Department of Commerce, August 24, 2007.

Bayesian Diagnostics for Detecting Hierarchical Structure, Methodology Section, Washington Statistical Society, March 23, 2007.

Introduction to Multilevel Analysis, Rural Research Methods Workshop, Rural Health Care Research Center, School of Nursing, University of Virginia, October 9, 2006.

Bayesian methodology which accounts for uncertainty about the commonality of a set of small area parameters. Invited paper, ENAR Spring Meeting, 2006.

Selected Conference Presentations

Kirk T, Ghazi, N, Yan G, Baras A, Tiedeman J, Conway B. Errors in Automated Retinal Thickness Measurements by Optical Coherence Tomography in Neovascular Age-Related Macular Degeneration. ARVO Annual Meeting, 2007.

Yan G, Greene T, and Beck G. Developing indices of disease severity in mortality prediction. ENAR Spring Meeting, 2005.

Rocco M, Miskulin D, Unruh M, Yan G, Athienities N, Kusek J, Levey A, Martin A, Meyer K, Ornt D and the HEMO Study Group. Modification of the ICED to Improve Its Predictive Ability for Mortality in Chronic Hemodialysis Patients: Results from the Hemodialysis (HEMO) Study. American Society of Nephrology 37th Annual Meeting, 2004.

Greene T, Yan G, Larive B and the HEMO Study Group. Counterfactuals and models for mean change in longitudinal outcomes in clinical trials with high mortality. Third Joint Meeting of the Society for Clinical Trials and International Society for Clinical Biostatistics, 2003.

Yan G, Greene T, Beck G, Kusek J, Leung J, Levey A, Paranandi L. Bias in longitudinal assessments of protein intake due to seasonal variations in studies of patients with kidney disease. 20th Annual Meeting of the Society for Clinical Trials, 1999.

Recent Publications

Yan G and Greene T. (2008). Investigating the effects of ties on measures of concordance. Statistics in Medicine . In press.

Yan G and Sedransk J. (2008). A Note on Bayesian Residuals in Hierarchical Model Diagnostic. Statistical Papers . In press.

Yan G and Sedransk J. (2007). Bayesian Diagnostic Techniques for Detecting Hierarchical Structure. Bayesian Analysis, 2, 735-760.

Cheung A, Rocco M, Yan G , Leypoldt J, Levin N, Greene T, Agodoa L, Bailey J, Beck G, Clark W, Levey A, Ornt D, Schulman G, Schwab S, Teehan B, Eknoyan G for the HEMO Study Group. (2006). Serum ß2-microglobulin levels predict mortality in dialysis patients: Results of HEMO Study. Journal of the American Society of Nephrology,17:546-555.

Delmez JA, Yan G , Bailey J, Beck GJ, Beddhu S, Cheung AK, Kaysen GA, Levey AS, Sarnak MJ, and Schwab SJ for the Hemodialysis (HEMO) Study Group. (2006). Cerebrovascular disease in maintenance hemodialysis patients: Results from the HEMO Study. American Journal of Kidney Disease, 47:131-138.

Yan G and Sedransk J. (2006). Exploring the use of subpopulation membership in Bayesian hierarchical model assessment. Journal of Data Science 4, 413-424.

Ng YH, Meyer KB, Kuse JW, Yan G, Rocco MV, Kimmel PL, Benz RL, Beddhu S, Dwyer JT, Toto RD, Eknoyan G, and Unruh ML. (2006). Hemodialysis timing, survival, and cardiovascular outcomes in the Hemodialysis (HEMO) Study. American Journal of Kidney Disease. 47(4):614-24.

Yan G and Sedransk J. (2005). Bayesian methodology which accounts for uncertainty about the commonality of a set of estimates: applications to survey sampling. Technical report.

Unruh M, Miskulin D, Yan G, Hays RD, Benz R, Kusek JW, Meyer KB and the HEMO Study Group. (2004). Racial differences in health-related quality of life among hemodialysis patients. Kidney International, 65:1482-1491.

Unruh M, Benz R, Greene T, Yan G, Beddhu S, DeVita M, Dwyer JT, Kimmel PL, Kusek JW, Martin A, Rehm-McGillicuddy J, Teehan BP, Meyer KB. (2004). Effects of hemodialysis dose and membrane flux on health-related quality of life in the HEMO Study. Kidney International, 66:1-12.

Cheung AK, Sarnak M, Yan G, Berkoben M, Heyka R, Kaufman A, Lewis J, Rocco M, Toto R, Windus D, Ornt D, Levey AS, for the HEMO Study Group. (2004). Cardiac diseases in maintenance hemodialysis patients: Results of the HEMO study. Kidney International, 65: 2380-2389.

Unruh M, Yan G , Radeva M, Hays Rd, Benz R, Athienites NV, Kusek J, Levey AS, Meyer KB and the HEMO Study Group. (2003). Bias in assessment of health-related quality of life in a hemodialysis population: a comparison of self-administered and interviewer-administered surveys in the HEMO Study. Journal of the American Society of Nephrology, 14: 2132-2141.

Rocco MV, Yan G, Gassman JJ, Lewis JB, Ornt D, Weiss B, Levey AS and the HEMO Study Group. (2002). Comparison of causes of death using HEMO Study and HCFA ESRD death notification classification systems. American Journal of Kidney Disease, 39(1):146-153.

Allen KL, Miskulin D, Yan G, Dwyer JT, Frydrych A, Leung J, Poole D and the Hemodialysis (HEMO) Study Group. (2002). Association of nutritional markers with physical and mental health in prevalent hemodialysis patients from the HEMO Study. Journal of Renal Nutrition, 12 (3):160-169.

Cheung AK, Yan G , Greene T, Daugirdas JT, Dwyer JT, Levin NW, Ornt DB, Schulman G, Eknoyan G and the HEMO Study Group. (2002). Seasonal variations in clinical and laboratory variables among chronic hemodialysis patients. Journal of the American Society of Nephrology, 13: 2345-2352.