Skip to:

Robert Erin Weiss

Professor of Biostatistics


DepartmentsType of Faculty
BiostatisticsFull Time
Contact Information

Room 51-269 CHS

Department of Biostatistics

UCLA Fielding School of Public Health

Los Angeles, CA 90095-1772

Areas of Interest: 

My biostatistical research areas include Bayesian methods for modeling data; univariate and multivariate longitudinal data analysis; hierarchical models; and complex non-linear models. I also work in model development, model selection and model checking. Motivation for much of my research comes from the statistical difficulties seen in my collaborative work, particularly in the analysis of human behavior. My colleagues and I study HIV+ and HIV-at-risk individuals, drug abusers, child nutrition in Kenya, Hospital Emergency Department visitors, and meta-analyses of cardiac intervention data among many other areas of application.

I teach classes in Statistical Graphics (Biostat 230), Bayesian Data Analysis (Biostat 234), longitudinal data analysis (Biostat 236 and 411) and multivariate statistics (Biostat 251). My classes have computing and writing components, because statistical practice requires that you calculate inferences and then communicate what you have learned. I particularly like working in an academic environment because of the variety of projects I get to work on and because I get to work with many students on research projects, paper writing, and as dissertation advisor.

PhD (1989), Statistics, University of Minnesota
MS (1987), Statistics, University of Minnesota
BS (1984), Mathematics, University of Minnesota
Selected Courses: 
Biostat M230, Statistical Graphics: Fall 2008, Spring 2011
Biostat M234, Applied Bayesian Inference: Winter 2010, Fall 2011, Fall 2012
Biostat M236, Analysis of Repeated Measures: Winter 2008, 2012, 2014
Biostat 251, Multivariate Biostatistics: Spring 2008, 2009, 2010, 2014
Biostat 411, Correlated Data: Winter 2009, 2011, 2013
Selected Publications: 

Zhu, Yuda and Weiss, Robert E. (2013). Modeling Seroadaptation and Sexual Behavior among HIV+ Participants with a Simultaneously Multilevel and Multivariate Longitudinal Count Model. Biometrics, 69, 214–224.

Hara, Motoaki; Huang, David Y.; Weiss, Robert E.; and Hser, Yih-Ing (2013). Concurrent Lifecourse Trajectories of Employment and Marijuana use: Exploring Interdependence of Longitudinal Outcomes. Journal of Substance Abuse Treatment, to appear.

Hess, Kristen L.; Javanbakht, Marjan; Brown, Joelle M.; Weiss, Robert E.; Hsu, Paul; Gorbach, Pamina M. (2013). Intimate Partner Violence and Anal Intercourse among Young Adult Heterosexual Relationships. Perspectives on Sexual and Reproductive Health, 45, 6–12. doi: 10.1363/4500613

Neumann, Charlotte G.; Bwibo, Nimrod O.; Jiang, Luohua; Weiss Robert E. (2013). School snacks decrease morbidity in Kenyan school children: a cluster randomized, controlled feeding intervention trial. Public Health Nutrition, to appear. doi:10.1017/S1368980013000876

Lam, Marcus; Klein, Sacha; Freisthler, Bridget; Weiss, Robert E. (2013). Child Center Closures: Does Nonprofit Status Provide a Comparative Advantage? Children and Youth Services Review, to appear.

Zhang, Qunfang; Fischer, Heidi J.; Weiss, Robert E.; Zhu, Yifang (2013). Ultrafine Particle Concentrations in and Around Idling School Buses. Atmospheric Environment, 69, 65–75.

Neumann, Charlotte G.; Jiang, Luohua; Weiss, Robert E.; Grillenberger, Monika; Gewa, Constance A.; Siekmann, Jonathan H.; Murphy, Suzanne P.; Bwibo, Nimrod O. (2013). Meat Supplementation Increases Arm Muscle Area in Kenyan Schoolchildren. British Journal of Nutrition, 109, 1230-1240. DOI: 10.1017/S0007114512003121

Sun, Benjamin C.; Hsia, Renee Y.; Weiss, Robert E.; Zingmond, David; Liang, Li-Jung; Han, Weijuan; McCreath, Heather; Asch, Steven M. (2013). Effect of Emergency Department Crowding on Outcomes of Admitted Patients. Annals of Emergency Medicine, 61, 605-611. 

le Roux, Ingrid M.; Tomlinson, Mark; Harwood, Jessica M.; O’Connor, Mary J.; Worthman, Carol M.; Mbewu, Nokwanele; Stewart, Jacqueline; Hartley, Mary; Swendeman, Dallas; Comulada, W. Scott; Weiss, Robert E.; Rotheram-Borus, Mary Jane (2012). Outcomes of Home Visits for Pregnant Township Mothers and their Infants in South Africa: a Cluster Randomised Controlled Trial, AIDS, to appear. doi: 10.1097/QAD.0b013e3283601b53

Pines, Heather A.; Gorbach, Pamina M.; Weiss, Robert E.; Hess, Kristen; Murphy, Ryan; Saunders, Terry; Brown, Joelle; Anton, Peter; Cranston, Ross D. (2012). Acceptability of Potential Rectal Microbicide Delivery Systems for HIV Prevention: A Randomized Crossover Trial. AIDS and Behavior, DOI 10.1007/s10461-012-0358-z.

Jyrala, Aarne; Weiss, Robert E.; Jeffries, Robin A.; Kay, Gregory L. (2012). Is Hypothyroidism Overlooked in Cardiac Surgery Patients? Open Journal of Thoracic Surgery, 2, 29–35.

Gabayan, Gelareh Z.; Asch, Steven M.; Hsia, Renee Y.; Zingmond, David; Liang, Li-Jung; Han, Weijuan; McCreath, Heather; Weiss, Robert E.; Sun, Benjamin C. (2012). Factors Associated with Short-Term Bounce-Back Admissions Following Emergency Department Discharge. Annals of Emergency Medicine, to appear.

Gewa, Constance A.; Murphy, Suzanne P.; Weiss, Robert E.; Neumann, Charlotte G. (2012). A School-Based Supplementary Food Programme in Rural Kenya Did Not Reduce Children’s Intake at Home. Public Health Nutrition, 16, 713-720. doi:10.1017/S1368980012003266

Murphy, Ryan D.; Gorbach, Pamina M.; Weiss, Robert E.; Hucks-Ortiz, Christopher; Shoptaw, Stephen J. (2012). Seroadaptation in a Sample of Very Poor Los Angeles Area Men Who Have Sex with Men. Aids & Behavior, 17, 1862-1872.. DOI 10.1007/s10461-012-0213-2.

Hsia, Renee Y.; Asch, Steven M.; Weiss, Robert E.; Zingmond, David; Liang, Li-Jung; Han, Weijuan; McCreath, Heather; Sun, Benjamin C. (2012). California Hospitals Serving Large Minority Populations Were More Likely Than Others To Employ Ambulance Diversion. Health Affairs, 31(8), 1767–1776.

Hess, Kristen L.; Javanbakht, Marjan; Brown, Joelle M.; Weiss, Robert E.; Hsu, Paul; Gorbach, Pamina M. (2012). Intimate Partner Violence and Sexually Transmitted Infections among Young Adult Women. Sexually Transmitted Diseases, 39, 366–371.

Long, J. K.; Murphy, S. P.; Weiss, R. E.; Nyerere, S.; Bwibo, N. O.; Neumann, C. G. (2012). Meat and Milk Intakes and Toddler Growth: A Comparison Feeding Intervention of Animal Source Foods in Rural Kenya. Public Health Nutrition, 15, 1100–1107.

Gorbach, Pamina M.; Weiss, Robert E.; Fuchs, Edward; Jeffries, Robin A.; Hezerah, Marjan; Brown, Stephen; Voskanian, Alen; Robbie, Edward; Anton, Peter; Cranston, Ross D. (2012). The Slippery Slope: Lubricant Use and Rectal Sexually Transmitted Infections: a Newly Identified Risk. Sexually Transmitted Diseases, 39, 59–64. PMC3244680.

Jilaihawi, Hasan; Chakravarty, Tarun; Weiss, Robert E.; Fontana, Gregory P.; Forrester, James; Makkar, Raj R. (2012). Meta-Analysis of Complications in Aortic Valve Replacement: Comparison of Medtronic-Corevalve, Edwards-Sapien and Surgical Aortic Valve Replacement in 8,536 Patients. Catheterization and Cardiovascular Interventions, 80, 128–138.

Cranston, Ross D.; Murphy, Ryan; Weiss, Robert E.; Da Costa, Maria; Palefsky, Joel; Shoptaw, Steven; Gorbach, Pamina M. (2012). Anal Human Papillomavirus Infection in a Street Based Sample of HIV-Positive Men. International Journal of STD and AIDS, 23, 195-200.

Weiss, Robert E.; Comulada, Scott; Rotheram-Borus, Mary Jane. (2012). How do you deal with longitudinal observations on children nested within families? How do you deal with a covariate that changes over time in one group but not another? In J. Bray, W. Pequegnat and the NIMH Consortium on Families and HIV/AIDS. Statistical Challenges in Studying Complex and Changing Families. AIDS and Behavior, 16, 441-451. DOI 10.1007/s10461-011-9881-6

Cheng, Karen G.; Ortiz, Daniel J.; Weiss Robert E.; Shi, Lu; Ovalle-Bahamón, Ricardo E.; Ernesto, Francisco; Grillo, Michael P.; Bing, Eric G. (2012). Patterns of Alcohol Consumption and Factors Influencing Problematic Drinking among Angolan Soldiers. Journal of Substance Use, 17(2), 138–149 doi:10.3109/14659891.2010.538462.

Ober, Allison J.; Iguchi, Martin Y.; Weiss, Robert E.; Gorbach, Pamina M.; Heimer, Robert; Ouellet, Lawrence J.; Shoptaw, Steven; Anglin, M. Douglas; Zule, William A. (2011). The Relative Role of Perceived Partner Risks in Promoting Condom Use in a Three-City Sample of High-Risk, Low-Income Women. Aids & Behavior, 15(7), 1347-1358. DOI 10.1007/s10461-010-9840-7. PMC3180610

Weiss, Robert E.; Jia, Juan; Suchard, Marc A. (2011). A Bayesian Model for the Common Effects of Predictors on Mixed Outcomes. Interface Focus, 1, 886-894. doi:10.1098/rsfs.2011.0041 PMC3262291

Hsia, Renee Y.; Asch, Steven M.;Weiss, Robert E.; Zingmond, David; Liang, Li-Jung; Han, Weijuan; McCreath, Heather; Sun, Benjamin C. (2011). Hospital Determinants of Emergency Department Left Without Being Seen Rates. Annals of Emergency Medicine, 58(1), 24–32.e3. PMC3126631

Comulada, W. Scott and Weiss, Robert E. (2010). Sample Size and Power Calculations for Correlations between Bivariate Longitudinal Data. Statistics in Medicine, 29, 2811-2824. PMID: 20827714. PMC3154746

Weiss, Robert E. and Wang, Yan (2009). Experimental Design and Sample Size Computations for Longitudinal Models. Frontiers of Statistical Decision Making and Bayesian Analysis — In honor of James O. Berger. Co-Editors: Ming-Hui Chen, Dipak K. Dey, Peter Mueller, Dongchu Sun, and Keying Ye. Springer. pp. 270–276.

Liang, Li-Jung; Weiss, Robert E.; Redelings, Benjamin; Suchard, Marc A. (2009). Improving Phylogenetic Analyses by Incorporating Additional Information from Genetic Sequence Databases. Bioinformatics, 25, 2530–2536. PMID: 19661240 PMCID: PMC2800350

Naik, Hursh; White, Anthony J.; Chakravarty, Tarun; Forrester, James; Fontana, Gregory; Kar, Saibal; Shah, Prediman K.; Weiss, Robert E.; Makkar, Raj (2009). A meta-analysis of 3773 patients treated with percutaneous coronary intervention or surgery for unprotected left main coronary artery stenosis. Journal of the American College of Cardiology: Cardiovascular Interventions Online. 2(8), 739–47. PMID: 19695542

Alber, Susan A. and Weiss, Robert E. (2009). A Model Selection Approach to the Analysis of Variance. Statistics in Medicine, 28, 1821–1840. PMID: 19387975

Jia, Juan and Weiss, Robert E. (2009). Outcome Clustering: Modeling the Common Effects of Predictors on Multiple Longitudinal Outcomes. Statistics in Medicine, 28, 1793–1804. PMID:19360840