Eva Murphy

Eva Murphy

Assistant Professor

Baylor University

Hi there!

I’m an Assistant Professor in the Department of Statistical Sciences at Baylor University. Prior to joining Baylor, I was a postdoctoral fellow at Wake Forest University, where I worked with Dr. Staci Hepler. I received my Ph.D. in Statistics from Clemson University under the advisement of Dr. Whitney Huang. My research interests lie at the intersection of environmental and public health, with a particular focus on developing statistical methods for causal inference with observational data, especially in settings where outcomes evolve across space and time. I develop methods that use latent factor models to represent unobserved, time- and space-varying processes and confounders that influence outcomes, allowing for flexible dependence structures and more credible counterfactual comparisons. My work integrates Bayesian modeling, spatial statistics, and causal methods to address complex questions in environmental and public health.

Interests

  • Environmental science
  • Public Health
  • Spatio-Temporal statistics
  • Latent variable models
  • Causal inference

Education

  • PhD in Mathematical and Statistical Sciences

    Clemson University

  • Master's in Mathematical Sciences

    University of West Florida

  • Bachelor's in Mathematical Sciences

    Babes-Bolyai University

Publications

Impact of Hurricane Florence on buprenorphine transactions for opioid use disorder: A dual-perspective synthetic control study

with Collin Cademartori, David Kline, Robert Hurley, Jae Yong, Cara L. McDonnell, Staci A. Hepler, Meredith C.B. Adams

  • Estimate the effect of Hurricane Florence (2018) on buprenorphine transactions for opioid use disorder in southeastern coastal North Carolina using a Bayesian generalized synthetic control approach.

  • Compare two perspectives on access: transactions grouped by where patients live versus where pharmacies are located.

  • Use streamflow data to capture flooding conditions during the hurricane.

  • Find disruptions in both patient- and pharmacy-level transactions, with the largest pharmacy-level decrease (about 22%) during the evacuation week.

  • Link to the publication.

Integrating data at multiple spatial scales to estimate the local burden of the opioid syndemic

with David Kline, Erin McKnight, Andrea Bonny, William C. Miller, Lance Waller, Staci A. Hepler

April 2024 – October 2024
  • Integrate spatially misaligned data from counties and ZIP codes to analyze the complex interactions of five opioid-related outcomes.

  • Apply GIS methods to align ZIP codes with ZIP Code Tabulation Areas (ZCTAs) for a more detailed exploration of the opioid epidemic, revealing critical localized impacts.

  • Emphasize the need for both granular and county-level data to avoid misinterpretations, particularly in rural and urban regions.

  • Link to the publication.

Understanding the Opioid Syndemic in North Carolina: A Novel Approach to Modeling and Identifying Factors

with David Kline, Kathleen L. Egan, Kathryn E. Lancaster, William C. Miller, Lance Waller, Staci A. Hepler

September 2023 – May 2024
  • Examine trends and relationships among different outcomes believed to reflect opioid misuse.

  • Employ a Bayesian dynamic spatial factor model to capture the interrelated dynamics within six different county-level outcomes related to opioid misuse in North Carolina.

  • Investigate trends and relationships among illicit opioid overdose deaths, emergency department visits, opioid use disorder treatments, buprenorphine prescriptions, and hepatitis C and HIV cases.

  • Develop a novel technique within a Markov chain Monte Carlo algorithm to overcome challenges in loadings matrix estimation, enhancing model identifiability.

  • Provide a deeper understanding of the opioid epidemic's dynamics across time and space to inform public health strategies.

  • Poster presentation / A brief video presentation
  • Link to the publication.

Modeling of wind speed and wind direction through a conditional approach

with Dr. Whitney Huang, Dr. Julie Bessac, Dr. Jiali Wang, Dr. Rao Kotamarthi

June 2021 – May 2023
  • Develop a directional wind speed distribution using a Weibull distribution in such a way that the parameters of the distribution depend on wind direction.

  • Construct the dependence of the parameters of the Weibull distribution on wind direction using harmonic regression via weighted least squares.

  • Analyze the changes in wind speed and wind direction from present to future climate scenarios.

  • Poster presentation / A brief video presentation
  • Link to the publication.

Manuscripts in Progress

Modeling Directional Seasonal Wind Speed Extremes Using a Two-Stage Extreme Value Periodic Regression Approach

with Dr. Whitney Huang, Dr. Brook Russell

Submitted to Environmetrics
  • Utilize methods from extreme value theory, namely the block maxima method and peaks-over-threshold method, to investigate the potential enhancement of estimating extreme wind speeds.

  • Block maxima, peaks-over-thresholds, and point process methods are utilized to model the upper tail of the conditional distribution of the extreme wind speed given wind direction.

  • Simulation studies, analysis of output from climate model simulation, and model comparisons are discussed.

Evacuation, Displacement, and Medication Access: Analysis of Hurricane Florence on Long-Term Opioid Therapy

with Collin Cademartori, David Kline, Lucy D'Agostino McGowan, Robert Hurley, Jae Yong, Cara L. McDonnell, Staci A. Hepler, Meredith C.B. Adams

In preparation
  • Estimate the effect of Hurricane Florence on weekly buprenorphine dispensing for patients on long-term opioid therapy across North Carolina three-digit ZIP code (ZIP3) regions.

  • Develop a hierarchical Bayesian synthetic control model that expresses the effect as the product of the proportion of the population displaced and the change in dispensing per unit increase in that proportion.

  • Use displacement estimates from the North Carolina Governor's Office to inform the prior for the displaced proportion, helping regularize estimates where the dispensing data alone carry limited information.

Causal Inference for Continuous Environmental Exposures: A Multi-Method Framework for Opioid-Related Health Outcomes

with Gifty Osei, Jaechoul Lee

In preparation
  • Develop a framework that brings together several causal inference methods to study how continuous environmental exposures relate to opioid-related health outcomes.

  • Part of the IMSI–NISS Ideas Lab: Data Science at the Intersection of Public Health and the Environment.

Spatio-temporal modeling of wind speed

with Dr. Whitney Huang, Dr. Ting Fung Ma

In preparation
  • Decompose the complex structure of the spatio-temporal wind speed process into smaller components that can be estimated more easily. Then combine these components to obtain an estimate of the overall process.

  • A smooth space-time function is used to capture the first-order mean structure, taking into account periodicity in time, and a combination of empirical orthogonal functions (EOFs) and a first-order dynamical Gaussian process is employed to characterize the potentially complex second-order covariance structure.

  • A crucial aspect of the proposed model is its utilization of the annual "circularity" concept, which introduces spatio-temporal replicates allowing for flexible nonstationary space-time modeling.

Experience

Assistant Professor

Baylor University

Waco, TX, USA

Postdoctoral Fellow

Wake Forest University

Winston-Salem, NC, USA

Graduate Research Assistant

Clemson University

Clemson, SC, USA
Awards:
  • Outstanding Graduate in Research Award
  • ENVR Student Paper Award
  • Dr. Kenyon Fairey Graduate Fellowship
  • Call Me Doctor Dissertation Completion Fellowship

Graduate Teacher of Record

Clemson University

Clemson, SC, USA

Teacher of Mathematics

Mid-Carolina High School / Wade Hampton High School

Newberry / Varnville, SC
High School Teacher of Mathematics

Adjunct Instructor

Piedmont Technical College

Online - Instructor

Adjunct Instructor

Midlands Technical College

Columbia, SC

Near to Peer Mentor

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