Research

Click here for my Research Gate profile and here for Google scholar.

Grants

Active Grants

• National Institutes of Health, National Institute of Drug Abuse, Proposal R01DA052214, "Spatio-temporal Methods for Surveillance of the Opioid Syndemic" Role: MPI (with David Kline - WFUHS).

• Los Alamos National Laboratory, Laboratory Directed Research & Development grant, Project 20220209ER, “Assessing Environmental and Health Impacts of Airborne Particulates,” 10/1/2021 - 9/30/2024, Role: co-I (PI Kimberly Kaufeld - LANL).

• National Science Foundation, Computational & Data-Enabled Science and Engineering in Mathematical and Statistical Sciences, Proposal 2151881, “Scalable Models, Fast Computation and Predictability for Ordinal Spatio-temporal Data,” 7/1/2022 - 6/30/2025, Role: co-PI (PI Rob Erhardt - WFU).

Completed Grants

• National Institutes of Health, National Institute of Drug Abuse R21DA045236, "A Bayesian Spatio-temporal Approach for Estimating County-Level Opioid Misuse Rates in Ohio," 2018 - 2021.

Publications

Submitted Papers

• Dong, Q.*, Kline, D., Hepler, S.A., "A Bayesian Spatio-temporal Model to Optimize Allocation of Buprenorphine in North Carolina." 

• Kline, D., Waller, L.A., McKnight, E., Bonny, A., Miller, W.C., Hepler, S.A. "A dynamic spatial factor model to describe the opioid syndemic in Ohio."

• McKnight, E., Dong, Q.*, Brook, D.L., Hepler, S.A., Kline, D.M., Bonny, A. "A descriptive study of opioid misuse prevalence and office-based buprenorphine access in Ohio: a call for a targeted and flexible approach."

• Hepler, S., Erhardt, R. "multiocc: An R package for spatio-temporal occupancy models for multiple species."

• Erhardt, R., Hepler, S.A., Wolodkin, D.*, Greene, A.+, "Spatio-Temporal Forecasting for the U.S. Drought Monitor."

• Kline, D., Hepler, S.A., Krawczyk, N., Waller, L., Cerda, M., "A multivariate multiple change point model to describe opioid overdose deaths across the United States."

• Hepler, S.A., Kline, D., McKnight, E., Bonny, A., Waller, L.A., "An integrated abundance model for estimating county-level prevalence of opioid misuse in Ohio."

•  Anderson, T.M., Hepler, S.A., Holdo, R., Donaldson, J., Erhardt, R., Hopcraft, G., Hutchinson, M., Huebner, S., Morrison, T., Muday, J., Palmer, M., Pansu, J., Pringle, R.,  Sketch, R.*, Packer, C., "Body-size dependent grazing during migration generates facilitation and promotes savanna stability." 

Published and Accepted Papers

• Hepler, S.A., Kaufeld, K., Liu, X.+ Kline, D., (2022) "Integrating public health surveillance and environmental data to inform spatial risk of exposure to Histoplasma." Epidemiology, 33(5), 654-659.

• Kline, D., Ji, Y.*,  Hepler, S.A., (2021) "A multivariate spatio-temporal model of the opioid epidemic in Ohio: A factor model approach." Health Services and Outcomes Research Methodology, 21, 42-53. (Link).

• Kline, D., Pan, Y., Hepler, S.A., (2021) "Spatio-temporal trends in opioid overdose deaths by race for counties in Ohio," Epidemiology, 32 (2), 295-302. (Link).

• Hepler, S.A., Erhardt, R., (2021) "A spatiotemporal model for multivariate occupancy data," Environmetrics, 32 (2). (Link).

• Hepler, S.A., Waller, L.A., Kline, D., (2021) "A multivariate spatio-temporal change point model of opioid overdose deaths in Ohio," Annals of Applied Statistics, 15(3), 1329-1342. (Link).

• Kline, D., Hepler, S.A., (2021) "Estimating the burden of the opioid epidemic for adults and adolescents in Ohio counties," Biometrics,  77(2). (Link).

• Kline, D., Hepler, S.A., McKnight, E., Bonny, A. (2019) “A joint spatial model of opioid associated deaths and treatment admissions in Ohio,” Annals of Epidemiology, 33, 19-23. (Link).

• Hepler, S.A., McKnight, E., Bonny, A., and Kline, D. (2019) “A latent spatial factor approach for synthesizing opioid associated deaths and treatment admissions in Ohio counties,” Epidemiology, 30(3), 365-370. (Link).

• Hepler, S.A., Erhardt, R., Anderson, T.M. (2018) “Identifying drivers of spatial variability with Bayesian occupancy models,” Ecology, 99(10), 2152-2158. (Link)

• Hepler, S.A., Herbei, R. (2017) “A Monte Carlo approach to quantifying discrepancies between intractable probability distributions,”  Journal of Statistical Computation and Simulation, 87, 8, 1666-1683. (Link)

• Anderson, T.M., White, S.A., Davis, B.*, Erhardt, R., Palmer, M., Packer C. (2016) “The spatial and temporal distribution of African savannah herbivores: species associations and habitat occupancy in a landscape context,”  Philosophical Transactions of the Royal Society B, 371: 20150314.(Link)

• White, S.A., Herbei, R. (2015) “A Monte Carlo approach to model error quantification in Bayesian parameter estimation,” Computational Statistics and Data Analysis, 83, 168 – 181. (Link)

* Master's Degree Student, + Undergraduate student

Possible Student Projects

I frequently work with both undergraduate and graduate students on research projects related to applications in environmental, ecological, and epidemiological statistics. Click HERE for a brief presentation of some possible student research topics. 

Snapshot Serengeti

You can learn more about the Snapshot Serengeti project and help out by classifying camera-trap images by clicking here.