Byeongyeob Choi, Ph.D.
Assistant Professor of Biostatistics
My research interests are in methodological problems and issues in causal inference. I am particularly interested in the development and application of causal inference methods such as propensity scores and instrumental variables for detecting and controlling confounding bias in observation studies. I am currently active at the Mays Cancer Center as a member of the Protocol Review Committee.
- 2015 - PhD - Biostatistics - University of North Carolina at Chapel Hill
- 2008 - MS - Statistics - Korea University
- 2006 - BS - Environmental Science and Ecological Engineering - Korea University
- 2006 - BS - Statistics (Double major) - Korea University
- 4/2019 - Adjunct Assistant Professor - University of Texas Health Science Center at Houston, School of Public Health in San AntonioSan Antonio
- 11/2016 - Assistant Professor - University of Texas Health Science Center at San Antonio, Epidemiology and Biostatistics, San Antonio
Instruction & Training
- 1/2019 - Present, Introduction to Biostatistics in Public Health (UT Health at Houston)
- 8/2017 - Present, Patient Orient Clin Res Method, The University of Texas Health Science Center
- 1/2017 - Present, Patient-Orient Clin Res Method, The University of Texas Health Science Center
Research & Grants
Comparative effectiveness research
My expertise is in methodological development in the areas of causal inference using instrumental variable analysis and negative control outcome calibration. My current interests are in estimating causal effects of treatments using propensity score and instrumental variable methods in observational studies. I am also experienced in applications and methodological development of prediction models to microarray data, metabolomics data and medication adherence data.
Funding Agency NIH-National Institute on Aging Title Identification of a missing key element underlying apoE2 neuroprotection in Alzheimer?s disease and the aging brain Status Active Period 9/2018 - 6/2023 Role Co-Investigator Grant Detail Funding Agency NIH/NCI Title (PQ3) Novel Tumor Intrinsic PD-L1 Signals Direct Tumor Status Active Period 6/2017 - 6/2022 Role Co-Investigator Grant Detail Assist in the analysis of data from ERβ-centered signaling axis indicating a previously unrecognized molecular handle for mobilizing tumor-extrinsic antitumor activity of ERβ in immune cells Funding Agency Department of Defense Title Early detection of castration-resistant prostate cancer by assessing interactions between circulating tumor cells and accompanying immune cells Status Active Period 9/2018 - 8/2021 Role Co-Investigator Grant Detail To develop a procedure to early identify CR patients with a risk score based on mechanical/ immunocytochemical profiling of blood-isolated cells. For its future clinical use, collection and analysis of cells? mechanical parameters, vetted for essentiality in this study, will be condensed into a bed side device. Specific Aims: 1 ? We will determine the role of EMT in mechanical fitness of CTCs by measuring their mechanical properties with atomic force microscopy (AFM). We will recapitulate the EMT in cell culture to follow mechanical fitness related biophysical and gene expression changes in model CTCs. Aim 2 ? We will define the role of CTC-macrophage interactions in mechanical fitness of CTCs. We will classify the macrophage populations and determine mechanical and gene expression phenotypes of interacting CTCs. We will recapitulate the interactions in cell culture and follow phenotypic changes in model CTCs contacting macrophages. Aim 3 - We will construct a model for patients? stratification predicting the risk of castration resistance based on the mechanical fitness of CTCs collected before the start of ADT. Funding Agency NIH, NCI Title Cancer Therapy & Research Center at UTHSCSA, P30 Status Active Period 8/1997 - 7/2019 Role Co-Investigator Grant Detail Support research efforts of Cancer Center investigators. Funding Agency NIH-Diabetes/Digestive/Kidney Diseases Title Sglt2 Inhibition and Stimulation of Endogenous Glucose Status Active Period 7/2016 - 6/2018 Role Consultant Grant Detail We and others have demonstrated that glucosuria produced by inhibition of the renal sodium-glucose transporter-2 (SGLT2) lowers the fasting plasma glucose (FPG) concentration but causes a ?paradoxical? increase in endogenous glucose production (EGP). Although the increase in EGP can be viewed as a compensatory mechanism that opposes urinary glucose loss and prevents the development of hypoglycemia in NGT individuals, in T2DM individuals it occurs while the plasma glucose concentration is still in the hyperglycemic range. Moreover, it offsets by ~50% the urinary glucose loss produced by SGLT2 inhibitors and attenuates their glucose lowering ability. The increase in EGP following SGLT2 inhibition is associated with an increase in plasma glucagon concentration and decrease in plasma insulin concentration. Because renal glucose production is stated to be unresponsive to an increase in the plasma glucagon concentration, it is likely that the liver contributes, at least in part, to the increase in EGP [which is triggered by glucosuria]. However, an increase in glucose production by the kidney cannot be excluded. We hypothesize that there is a previously unrecognized, [completely novel] ?reno-hepatic? interaction that participates in the regulation of plasma glucose concentration. Funding Agency NIH/NCATS Title Institute for Integration of Medicine & Science: A Partnership to Improve Health (Clinical and Translational Science Award) Status Active Period 5/2013 - 4/2018 Role Co-Investigator Grant Detail This Clinical and Translational Science Award (CTSA) provides a broad range of infrastructure support across the institution and its CTSA partners. This UL1 component provides all CTSA support except for the KL2 Career Development Award and TL1 Training Award, which are listed separately. I served as the NIH Contact PI and Director of the IIMS. Note that this 2013-2018 CTSA comprises a new award (with a different grant number) from the 2008-2013 CTSA, due to a change in the NIH sponsoring center from NCRR to NCATS. Also note that due to NIH delays the period from 05/2013 to 09/2013 was funded by an extension of the prior award, but for consistency those funds are included in the first year amount reported here.
Funding Agency V Foundation Title A novel therapeutic approach for endocrine resistant breast cancer by inhibiting a targeted epigenetic program Status Active Period 11/2017 - 10/2020 Role Co-Investigator Grant Detail Develop a novel therapeutic approach for endocrine resistant breast cancer by inhibiting a targeted epigenetic program.
Funding Agency Cancer Prevention Research Institute of Texas (CPRIT) Title Mechanisms and treatment of hippocampal cognitive impairment associated with androgen deprivation therapy for prostate cancer Status Active Period 3/2018 - 2/2021 Role Co-Investigator Grant Detail This project will identify mechanisms of cognitive impairment after ADT that may be viable therapeutic targets, inform a potential new use for vortioxetine in treating it, and ultimately improve the quality of life of prostate cancer survivors treated by ADT.
Funding Agency NIH-Diabetes/Digestive/Kidney Diseases Title Durability of Early Combination Therapy vs Conventional Status Active Period 9/2015 - 8/2018 Role Consultant Grant Detail The hypothesis is that the initiation of combination therapy with a glucagon-like peptide-1 analogue (liraglutide) plus a thiazolidinedione (pioglitazone) in type 2 diabetic subjects poorly controlled blood glucose levels on metformin plus sulfonylurea (SU) will achieve superior and more durable glycemic control with fewer side effects compared to basal-bolus insulin. Accordingly we will compare the efficacy and safety of initiating combination therapy with liraglutide plus pioglitazone versus basal (glargine) plus premeal insulin in type 2 diabetic subjects who are suboptimally controlled (HbA1c > 7.0%) with metformin plus SU on the achievement of optimal glycemic control (HbA1C
Desai PA, Kakarla S, Saksena A, Choi B, Goros M, Miller FR, Karnad AB, Cervantez SR. Pretreatment obesity prolongs survival in elderly patients (≥ 65 years) with head and neck cancer (HNC); 2019 May. (Journal of Clinical Oncology; vol. 37, no. 15). Wang W, Shim YK, Michalek JE, Barber E, Saleh LM, Choi BY, Wang C-P, Ketchum N, Costello R, Marti GE, Vogt R, Landgren O, Calvo KR. Measurement of Serum microRNAs in US Veterans with Monoclonal Gammopathy of Undetermined Significance; 2018 Jan. (Blood; vol. 132).
Wang W, Shim YK, Michalek JE, Barber E, Saleh LM, Choi BY, Wang CP, Ketchum N, Costello R, Marti G, Vogt RF, Landgren O, Calvo KR. Serum microRNA profiles among dioxin exposed veterans with monoclonal gammopathy of undetermined significance Journal of Toxicology and Environmental Health, Part A 2020 Apr;83(7):269-278. Ramirez A, Choi BY, Munoz E, Perez A, Gallion K, Moreno P, Penedo F. Assessing the Effect of Patient Navigator Assistance to Psychosocial Support Services on Health-Related Quality of Life in a Randomized Clinical Trial in Latino Breast, Prostate, Colorectal Cancer Survivors Cancer 2020 Mar;126(5):1112-1123. Kaushik D, Shi Z, Liss MA, Wang H, Jha RP, Choi BY, Pruthi DK, Ha CS, Mansour AM, Svatek RS. Screening Logs from a Pilot Randomized Controlled Trial of Radical Cystectomy Versus Chemoradiation Therapy for Muscle-Invasive Bladder Cancer Urologic Oncology: Seminars and Original Investigations 2020 Jan;38(1):4.e1-4.e6. McLaughlin JE, Choi BY, Liu Q, Gelfond JA, Robinson RD, Chang TA, Knudtson JF. Does Assisted Hatching Affect Live Birth in Fresh, First Cycle In-vitro Fertilization in Good and Poor Prognosis Patients? Journal of Assisted Reproduction and Genetics 2019 Dec;36(12):2425-2433. Khan HI, Franks NJ, Liu Q, Choi BY, Smith ER, Daskovich TJ, Liss MA. Online Reviews of American Urologists and Opportunities for Improvement Urology Practice (Accepted) 2019 Dec;. Choi BY, Lee JW. The Isotonic Regression Approach for an Instrumental Variable Estimation of the Potential Outcome Distributions for Compliers Computational Statistics and Data Analysis 2019 Nov;139:134-144. Lopera JE, Arthur J, Nemeh F, Liu Q, Choi B, Walker J, Garza-Berlanga A, Kroma G, Suri R. Microwave Ablation in Hepatocellular Carcinoma. Single US Center Long-Term Imaging and Clinical Follow-up Results Current Research in Surgery 2019 Oct;2(1):8-15. Choi BY, Gelfond J. The Validity of Propensity Score Analysis Using Complete Cases with Partially Observed Covariates European Journal of Epidemiology (Accepted) 2019 Jul;. Choi BY, Wang C-P, Michalek J, Gelfond J. Power Comparison for Propensity Score Methods Computational Statistics 2019 Jun;34(2):743-761. Choi BY, Fine JP, Brookhart MA. On Two-Stage Estimation of Structural Instrumental Variable Models Biometrika 2017 Dec;104(4):881-899. Choi BY, Bair E, Lee JW. Nearest Shrunken Centroids via Alternative Genewise Shrinkages PLoS ONE 2017 Feb;12(2).