Caitlin Ward

Caitlin Ward

Assistant Professor

University of Minnesota

About

Welcome! I am an assistant professor at the University of Minnesota Division of Biostatistics and Health Data Science. My methodological research focuses on the development of Bayesian models in settings with complex or correlated data, such as infectious disease modeling, spatio-temporal disease mapping, and spatial analysis of multiplex proteomics imaging data. Prior to joining the faculty at Minnesota, I completed a CANSSI distinguished postdoctoral fellowship at the University of Calgary studying behavioral change in infectious disease systems under the supervision of Dr. Rob Deardon and Dr. Alexandra Schmidt. I received my PhD in Biostatistics from the University of Iowa in May 2021, working with Dr. Grant Brown and Dr. Jacob Oleson. In my thesis I developed novel Bayesian methods for infectious disease modeling at both the individual and population-level.

One of my favorite parts of being a biostatistician is the ability to collaborate with researchers across many disciples. While at the University of Iowa, I worked in the Biostatistics Consulting Center for four years, and was privileged to collaborate with researchers in nursing, radiology, and communication sciences, among others. Recently, much of my collaborative efforts have focused on analyzing the effects of nurse elderspeak on resistiveness to care in hospitalized persons living with dementia, in efforts to improve person-centered dementia care. Some of my other collaborations have used machine learning methods and radiomics data for tumor classification. I have also worked on projects using longitudinal methods, survival and network analysis, as well as more traditional regression modeling.

In my free time, I enjoy spending time with family, baking, and all things volleyball related.

Download my CV.

Interests
  • Spatio-temporal modeling
  • Spatial omics analysis
  • Bayesian statistics
  • Infectious diseases
  • Cancer
  • Dementia care
Education
  • PhD in Biostatistics, 2021

    University of Iowa

  • MS in Biostatistics, 2018

    University of Iowa

  • BS in Statistics, 2016

    Iowa State University

Selected Recent Publications

The Iowa Coding Scheme for Elderspeak: Development and Validation

Featured in the New York Times: Honey, Sweetie, Dearie: The Perils of Elderspeak

Background and Objectives

Elderspeak is communication that sounds like babytalk and is a common form of communication often used in dementia care. The purpose of this research was to develop and validate the Iowa Coding for Elderspeak (ICodE) scheme, as a means of standardizing the coding of elderspeak across studies.

Research Design and Methods

The ICodE categorizes communicative interactions by nursing staff into 5 states that encompass who is speaking, who is being addressed, and in what manner. ICodE also captures different attributes of elderspeak, such as vocabulary usage and prosodic modifications. Intra-rater and inter-rater reliability were evaluated for each communication state. Convergent validity was evaluated by comparing the use of elderspeak to ratings of emotional tone by 31 community-dwelling older adults and to the occurrence of rejection of care during 88 observations of hospital dementia care.

Results

Inter-rater and intra-rater reliability were excellent for each communication state with confidence intervals ranging from moderate to excellent. Convergent validity with the emotional tone ratings was established for 10 of the 11 elderspeak attributes, indicating that older adults perceive these attributes as more patronizing and/or less respectful than neutral speech. Convergent validity with rejection of care was established for 8 of the attributes, suggesting that these aspects of elderspeak were also negatively perceived by individuals living with dementia.

Discussion and Implications

The ICodE is an evidence-based coding scheme that can reliably and validly document the use of elderspeak by nursing staff and that will facilitate uniformity in elderspeak research going forward.

Ruminant-dense environments increase risk of reported Shiga toxin-producing Escherichia coli infections independently of ruminant contact

Cattle and other domestic ruminants are the primary reservoirs of O157 and non-O157 Shiga toxin-producing Escherichia coli (STEC). Living in areas with high ruminant density has been associated with excess risk of infection, which could be due to both direct ruminant contact and residual environmental risk, but the role of each is unclear. We investigated whether there is any meaningful risk to individuals living in ruminant-dense areas if they do not have direct contact with ruminants. Using a Bayesian spatial framework, we investigated the association between the density of ruminants on feedlots and STEC incidence in Minnesota from 2010 to 2019, stratified by serogroup and season, and adjusting for direct ruminant contact. For every additional head of cattle or sheep per 10 acres, the incidence of O157 STEC infection increased by 30% (incidence rate ratio [IRR] 1.30; 95% credible interval [CrI] 1.18, 1.42) or 135% (IRR 2.35; 95% CrI 1.14, 4.20), respectively, during the summer months. Sheep density was also associated with O157 STEC risk during winter (IRR 4.28; 95% CrI 1.40, 8.92). The risk of non-O157 STEC infection was only elevated in areas with goat operations during summer (IRR 19.6; 95% CrI 1.69, 78.8). STEC risk associated with ruminant density was independent of direct ruminant contact across serogroups and seasons. Our findings demonstrate that living in a ruminant-dense area increases an individual’s risk of O157 and non-O157 STEC infection even without direct ruminant contact, indicating that prevention efforts need to extend to community strategies for averting indirect transmission from local ruminant populations.

Melanoma-Derived Extracellular Vesicles Induce CD36-Mediated Pre-Metastatic Niche

CD36 expression in both immune and non-immune cells is known to be directly involved in cancer metastasis. Extracellular vesicles (EVs) secreted by malignant melanocytes play a vital role in developing tumor-promoting microenvironments, but it is unclear whether this is mediated through CD36. To understand the role of CD36 in melanoma, we first analyzed the SKCM dataset for clinical prognosis, evaluated the percentage of CD36 in lymphatic fluid-derived EVs (LEVs), and tested whether melanoma-derived EVs increase CD36 expression and induce M2-macrophage-like characteristics. Furthermore, we performed a multiplex immunofluorescence (MxIF) imaging analysis to evaluate the CD36 expression and its colocalization with various other cells in the lymph node (LN) of patients and control subjects. Our findings show that cutaneous melanoma patients have a worse clinical prognosis with high CD36 levels, and a higher percentage of CD36 in total LEVs were found at baseline in melanoma patients compared to control. We also found that monocytic and endothelial cells treated with melanoma EVs expressed more CD36 than untreated cells. Furthermore, melanoma-derived EVs can regulate immunosuppressive macrophage-like characteristics by upregulating CD36. The spatial imaging data show that cells in tumor-involved sentinel LNs exhibit a higher probability of CD36 expression than cells from control LNs, but this was not statistically significant. Conclusively, our findings demonstrated that CD36 plays a vital role in controlling the immunosuppressive microenvironment in the LN, which can promote the formation of a protumorigenic niche.

Projects

An Intuitive, Interactive, Introduction to Biostatistics

An Intuitive, Interactive, Introduction to Biostatistics

Open Educational Resource for introductory biostatistics.

BayesSEIR

BayesSEIR

An R package to implement Bayesian SEIR models.