Statistician

Curriculum Vitae

Ja Kook Gu

Statistician/Biostatistician/Data Analyst

*** ******** **

Morgantown, WV 26505-2888

Phone: 304-***-**** (Cell), E-mail: ********@*****.***

Citizenship: US Citizen

Education

M.S. in Biostatistics, December 1997, University of South Carolina, Columbia, South Carolina

B.S. in Mathematics, May 1994, University of North Carolina at Charlotte, Charlotte, North Carolina

Professional Certification

SAS Advanced Programming Certification by SAS Institute

SAS Base Programming Certification by SAS Institute

Professional Experience

Sep. 2007 – Jun. 2025 Statistician

Bioanalytics Branch, Health Effects Laboratory Division

National Institute for Occupational Safety & Health (NIOSH), CDC, Morgantown, WV

Duties:

Providing statistical consultation and advice on optimal design and analysis that

enhance scientific quality of laboratory, clinical or epidemiologic research

Identifying appropriate analytical methods and statistical programs to address study objectives, providing summary of analytic results and appropriate interpretation

Developing statistical analysis plan as a collaborative effort

Verifying and documenting data to ensure suitability for proposed analysis

Documenting analytical results and verifying their accuracy

Summarizing, interpreting, and reporting research findings to collaborators.

Preparing research findings for presentation at seminars, scientific meetings, and for publication in peer-reviewed journals.

Contributes to or develops statistical relevant sections of a presentation or peer-reviewed publication.

Reviewing research plans, suggesting appropriate improvements and providing advice on population, study design, sample size and duration

Performing data conversion, cleaning, and documentation for BCOPS studies

Conducted quality control analyses for the clinical chemistry data

Reviewer for manuscripts submitted for clearance and for journal publication

Providing technical support in SAS programming for co-workers

Conducting epidemiological research for branch studies

Gene expression data analysis.

Projects participated in:

Buffalo Cardio-Metabolic Occupational Police Stress Study (BCOPS) in Baseline study (2004-2009), 1st follow-up study (2011-2015), and 2nd follow-up study (2016-2019).

Buffalo Police Heart Rate Variability Study

Buffalo Police Mortality / Cancer Incidence Study

Buffalo Police Microvascular study – Retinal Examination

Longitudinal study of Work Stress and Cardiovascular Disease in Police Officers (2023-2026)

Occupational Exposures and Autism Study

Longitudinal Examination of Mental and Physical Health among Police Associated with COVID-19

Assessment of First Responder Well-being in Northwest Tribal Community (2023-2025)

BCOPS cancer incidence study

Software: SAS 9.4, R 3.3, RStudio, SUDAAN 11, SPSS 15.0 (statistics software), Adobe Acrobat X Pro, MS Office (Word, Access, Excel, PowerPoint, Outlook), OCMAP (Occupational Cohort Mortality Analysis Program)

Nov. 2000 – Aug. 2007 SAS Programmer & Biostatistician

Department of Biostatistics, Bioinformatics, and Epidemiology,

Medical University of South Carolina, Charleston, SC.

Duties:

SAS programming and data processing with data cleaning and weighting

Data analysis with regression analysis, general linear model, analysis of variance, categorical data analysis, survival analysis

Data evaluation of incidence, prevalence, and sensitivity

Reporting South Carolina TBI/TSCI data to CDC annually

Database development and management in MS Access

Participation of measurements of abstracted questionnaire and interview survey questionnaire

Assistance with statistical analysis for publications and presentations

Programming in SAS for manipulating/creating new data sets

Creating output files with SAS/ODS, graphs, and tables

Collaboration with other agencies to produce timely reports

Projects participated in:

South Carolina Traumatic Brain Injury (TBI) Registry and Follow-up Study

South Carolina Traumatic Spinal Cord Injury (TSCI) Follow-up Study

South Carolina TBI/TSCI Hospital Discharge Data Surveillance System

South Carolina TBI/TSCI Emergency Department Data Surveillance System

Health Outcome on Epilepsy and Seizures in South Carolina

Software: SAS V6 V7 V8 V9, Epi-info6, Visual Slick, MS Word, MS Access, FrontPage

2000, MS Excel, MS PowerPoint, Winzip, Internet Explore.

Sept. 1999–Oct. 2000 Biostatistician & Data Analyst

Office of Prevention, Department of Disabilities and Special Needs (DDSN), State of South Carolina, Columbia, SC.

Duties:

SAS programming and statistical analysis of South Carolina Head And Spinal

Cord Injury (SCHASCI) morbidity and mortality data

Collaboration with other agencies to produce timely reports relative to SCHASCI

Cleaning, modifying, and analysis of abstracted hospital discharge and emergency department visit data in accordance with NETSS format to provide CDC with SC surveillance data

Participation in a grant proposal to establish the surveillance system with funding

opportunities for in-depth research

Software: SAS V6, Epi-info6, Visual Slick, MS Word, MS Excel, MS PowerPoint,

Netscape, Internet Explore.

Jan. 1998–Aug. 1999 SAS Programmer

Computer Consulting Group, Spartanburg, SC.

Duties:

Renovation of Year 2000 millennium problems in commercial SAS programs

Checking all program statements and statistical procedures

Identifying date sensitive variables and changing the codes properly in Year 2000

Creating JCL and data sets to do program test on Year 2000

Software: Mainframe SAS V6.8, PC SAS V6.12, LOTUS WordPro, LOTUS Approach

Computer Skills

SAS Software: SAS/BASE, SAS/MACRO, SAS/SQL, SAS/STAT, SAS/IML, SAS/GRAPH,

SAS/INSIGHT.

Statistical Software: SUDAAN, R, RStudio, S-Plus, SPSS, Minitab, Epi-Info,

OCMAP (Occupational Cohort Mortality Analysis Program)

Other Software: MS Office (Word, Excel, Access, PowerPoint, Outlook, Lync), Adobe Acrobat

Programming: SAS/BASE, SAS/MACRO, SAS/SQL, R, S-Plus, Python

Operating system: MS-Windows 10, Mac OS, UNIX

Statistical Analysis Skills

Descriptive analysis: Univariate analysis (means, standard deviation, normality, confidence interval),

Frequency distributions, Graphs of bar and plot.

Categorical analysis: Chi-square test, McNemar’s test, Mantel-Haenszel Chi-square test,

Odds Ratio, Relative Risk

Longitudinal analysis: Calculations for date related, Frequency distribution, T-test

Regression, Pearson/Spearman correlation, Logistic Regression-dichotomous response

Survey analysis: Survey means, survey frequencies, survey regression, weighting

Survival analysis: Hazard rate, Log-Rank test, Life test for survival time, Proportion-hazard regression

Experimental analysis: One-way/two-way ANOVA, generate randomized design with PROC PLAN,

n-way factorial design, Power analysis for sample allocation, Repeated measures design,

Nonparametric analysis

Nonparametric analysis: Sign test, Wilcoxon test, Kruskal-Wallis test

Others: Kappa test – a measure of interrater reliability.

Cronbach's alpha - a measure of internal consistency/reliability.

Stat. SAS Procedures: MEANS, FREQ, UNIVARIATE, FORMAT, CORR, TTEST, NPAA1WAY,

REG, GLM, LOGISTIC, CATMOD, ANOVA, LIFEREG, LIFETEST, PHREG,

MIXED for linear mixed models, GLIMMIX for generalized linear mixed models,

NLMIXED for nonlinear mixed models,

SURVEYMEANS, SURVEYFREQ, SURVEYREG, SURVEYLOGISTIC, SURVEYPHREG,

Stat. SUDAAN Procedures: CROSSTAB, DESCRIPT, RATIO, REGRESS, LOGISTIC, MULTLOG, LOGLINK, SERVIVAL.

R / RStudo:

Machine Learning packages:

bkmr (Bayesian Kernel Machine Regression), randomForest,

CARTs (Classification and Regression Trees)

Statistical modeling packages:

jomo (multilevel joint modeling), ordinal (regression models for ordinal data),

survival (Survival Analysis), poLCA (polytomous variable Latent Class Analysis),

Genetic analyses packages:

lumi, limma, HardyWeinberg,

Visual graphics packages:

graphics,tidyverse, ggplots, markdown

Exploratory Data Analysis packages:

tidyverse, modelr (pattern), ggplots, markdown

Data imports packages:

tibble, readr, tidyr

Data transformation packages:

tidyverse, tidyr, foreign, haven, dplyr (splitting and combining data), gdata

Dates and Times packages:

lubridate

Publications (selected the publications in 2019-2025)

Gu JK, Charles LE, Lim CS, Mnatsakanova A, Anderson S, Dzubak L, McCanlies EC. Serum Concentration of Selected Per- and Polyfluoroalkyl Substances (PFAS) by Industry and Occupational Groups among US Adult Workers, NHANES 2005-2014. Am. J of Ind Med, submitted December 18, 2024

McCanlies EC, Gu JK, Ma CC, Sanderson WT, Ludeña-Rodriguez YJ, Hertz-Piccioto I. The Effects of Parental Occupational Exposures on Autism Spectrum Disorder Severity and Skills in Cognitive and Adaptive Domains. International Journal of Hygiene and Environmental Health, submitted January 10, 2025.

Lim C, Gu J, Ma Q. The ETS domain-containing hematopoietic transcription factor PU.1 mediates the induction of arachidonate 5-lipoxygenase by multi-walled carbon nanotubes in macrophages in vitro. Archives of Toxicology 2025;99:597-610. https://doi.org/10.1007/s00204-024-03925-w

Charles LE, Gu JK, Violanti JM. Impact of Shiftwork on Retinal Vasculature Diameters over a 5-Year Period: A Preliminary Investigation Using the BCOPS Study Data. Int. J Env Res & Public Health, 2024, 21,439. https://doi.org/10.3390/

McCanlies EC, Gu JK, Kashon M, Yucesoy B, Ma CC, Sanderson WT, Kim K, Ludena-Rodriguesz Y, Hertz-Piccioto I. Parental occupational exposure to solvents and autism spectrum disorder: An exploratory look at gene-environment interactions. Environmental Research, 2023;228:115769. DOI: 10.1016/j.envres.2023.115769

Charles L, Gu J, Violanti JM [2024]. Impact of Shiftwork on Retinal Vasculature Diameters over a 5-Year Period: A Preliminary Investigation Using the BCOPS Study Data. Int. J. Environ. Res. Public Health.

Gu JK, Charles LE, Allison P, Violanti JM, Andrew ME. Mental health treatment reported by US workers before and during the COVID-19 pandemic: United States (2019-2020). Int. J. Environ. Res. Public Health 2023, 20(1), 651; https://doi.org/10.3390/ijerph20010651

Gu JK, Allison P, Charles LE, Ma CC, Groenewold M, Andrew ME, Luckhaupt SE. Prevalence of Self-Reported Prescription Opioid Use and Illicit Drug Use among U.S. Adult Workers: NHANES 2005-2016. JOEM, 2022;64(01):39-45. doi:10.1097/JOM.0000000000002328

Gu JK, Charles LE, Violanti JM, Andrew ME. Association between the metabolic syndrome and retinal microvascular diameters among police officers. JOEM, 2022;64(9)748-758. doi: 10.1097/JOM.0000000000002569.

Naimo M, Gu JK. The Relationship between Resistance Training Frequency and Muscle. Int J Environ Res Public Heath, 2022, 19(13), 8099; https://doi.org/10.3390/ijerph19138099

Gu JK, Charles LE, Fekedulegn D, Allison P, Ma CC, Violanti JM, Andrew ME. Temporal trend of CVD and risk factors among US older workers: NHIS 2004-2018, Annals of Epidemiology, 2021;55:78-720, https://doi.org/10.1016/j.annepidem.2020.10.002, PMID: 33049395

Violanti JM, Gu JK, Charles LE, Fekedulegn D, Andrew ME. Dying for the job: Police Mortality, 1950-2018. Policing; An International Journal, 44(6) 1014-1030, October 22, 2021. https://doi.org/10.1108/PIJPSM-06-2021-0085

Gu JK, Charles LE, Fekedulegn D, Ma CC, Violanti JM, Andrew ME. Occupational Injury and Psychological Distress among U.S. Workers: The National Health Interview Survey, 2004-2016, Journal of Safety Research, 2020;74:207-217. doi: 10.1016/j.jsr.2020.06.002

Ma CC, Gu JK, Ruchi B, Charles LE, Violanti JM, Fekedulegn D, Andrew ME. Associations of objectively measured sleep characteristics and incident hypertension among police officers: the role of obesity. J Sleep Res., 2020;29:e12988. DOI: https://dio.org/10.1111/jsr.12988

Gu JK, Charles LE, Millen AE, Violanti JM, Ma CC, Jenkins E, Andrew ME. Associations between Adiposity Measures and 25(OH)D and Comparison of Adiposity Measures as Predictors of 25(OH)D Insufficiency among Police Officers. American Journal of Human Biology, 2019;e23264. https://doi.org/10.1002/ajhb.23274

Shi M, Gu J, Hartley T, Violanti J, Andrew M, Fekedulegn M. Shift work and ideal cardiovascular health among law enforcement officers. Annals of Epidemiology 40:39. (published the abstract)

many

Presentations (selected the most recent five presentations)

Ja K. Gu, Erin McCanlies, John M. Violanti, Anna Mnatsakanova, Samantha Services, Penelope Allison, Luenda E. Charles. Mixtures Effect of Police Stressors on Psychological Health, a Machine Learning Approach. 2025 Society for Epidemiologic Research (SER) Conference, Boston, MA, June 10-13, 2025

JK Gu, LE Charles, S Anderson, L Dzubak, A Mnatsakanova, E McCanlies. Serum concentration of selected per-and poly-fluoroalkyl substances (PFAS) by industry and occupational groups among US adult workers, NHANES 2005-14. 2024 American College of Epidemiology (ACE) Conference, Columbus, OH, September 8-11, 2024

Ja K. Gu, Luenda E. Charles, Desta Fekedulegn, Samantha Service, John M. Violanti. Identifying Comorbidity Patterns among Police Officers using medications: a Latent Class Analysis, 2023 Society for Epidemiologic Research (SER), June 13-16, 2023, Portland, OR.

Ja K. Gu, Luenda E. Charles, Penelope Allison, John M. Violanti, Michael E. Andrew. Mental health treatment before and during COVID-19 pandemic. 2022 American College of Epidemiology (ACE) Annual Meeting, September 8-11, 2022, Scottsdale, AZ.

Ja K. Gu, Luenda E. Charles, Violanti, Michael E. Andrew. Mental health treatment before and during COVID-19 pandemic. 3rd International Symposium to Advance Total Worker Health, October 11-14, 2022, National Institutes of Health Natcher Conference Center, Bethesda, Maryland.

many

Honors and Awards

Alice Hamilton Award, CDC/NIOSH (2023)

Alice Hamilton Award, CDC/NIOSH (2021)

Alice Hamilton Award Nominee, CDC/NIOSH (2020)

Charles C. Shepard Science Award, CDC (2016)

Professional Organizations

Member of Society of American Statistics since 2010

Editor in Journal of Police Science since 2023

Member of CDC SAS User Group since 2013

Member of CDC R User Group since 2015

Member of NIOSH AI Interest Group since 2025

References

Oliver Wirth PhD, Psychologist, Branch Chief, 304-***-****, *****.******@*******.***

Michael Andrew PhD, Statistician, former Branch Chief, 204-***-****, ********@*******.***

Dest Fekedulegn PhD, Statistician, Leader of statistical team, 304-***-****, *********@*****.***

Erin McCanlies PhD, Epidemiologist, Project leader, 304-***-****, ********@*****.***

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