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Open Access Publications from the University of California

Scholarly Works (4 results)

  • Thesis
  • Peer Reviewed
UC Santa Barbara Electronic Theses and Dissertations (2024)

This dissertation presents four distinct applications in Population and Health Geography. While varied, in each of these applications I center geographic constructs (space, time, exposure and scale), and implement a specific study design (often with novel methods and/or measures) to elucidate these themes in context. In particular, I trace the challenges of measuring exposure, effects, and uncertainty through each application. In the first application I use historical wildfire evacuation zones to identify wildfire exposed populations and investigate the relationship between wildfire exposure and cardiovascular events. For the second application, I describe and test a new time use data collection method in the context of existing tools and simulation models. In the third application I introduce a statistical model into wildfire vulnerability index construction and discuss implications for spatial variability. For the final application I construct a novel indirect measure of school climate and combine multiple data sources to explore mental health variation across school districts in New York City. Together these applications demonstrate the natural partnership of Geography and Statistics in social science.

    Cover page: Statistical Applications in Population, Health and Geography: At Home in the Twilight Zone
    • Article
    • Peer Reviewed
    UC Santa Barbara Previously Published Works (2024)
    In practice, survival analyses appear in pharmaceutical testing, procedural recovery environments, and registry-based epidemiological studies, each reasonably assuming a known patient population. Less commonly discussed is the additional complexity introduced by non-registry and spatially-referenced data with time-dependent covariates in observational settings. In this short report we discuss residual diagnostics and interpretation from an extended Cox proportional hazard model intended to assess the effects of wildfire evacuation on risk of a secondary cardiovascular events for patients of a specific healthcare system on the California's central coast. We describe how traditional residuals obscure important spatial patterns indicative of true geographical variation, and their impacts on model parameter estimates. We briefly discuss alternative approaches to dealing with spatial correlation in the context of Bayesian hierarchical models. Our findings/experience suggest that careful attention is needed in observational healthcare data and survival analysis contexts, but also highlights potential applications for detecting observed hospital service areas.
      Cover page: Residuals in space: Potential pitfalls and applications from single-institution survival analysisCreative Commons 'BY' version 4.0 license
      • Article
      • Peer Reviewed
      UC Santa Barbara Previously Published Works (2023)
        Cover page: Wildfire, evacuation, and cardiovascular events: A spatial exposure approachCreative Commons 'BY' version 4.0 license
        • Article
        • Peer Reviewed
        UC Santa Barbara Previously Published Works (2025)

        Background

        As rates of depression and anxiety continue to rise, prevention, and treatment of poor mental health in adolescents is a major challenge for population health. Within the US context, a growing body of literature is examining the relationship between school climate and student mental health.

        Methods

        We extend the notion of school climate and mesosystem effects by creating an emergency department visit intensity, a novel indirect summary measure related to both the prevalence of depressive symptoms and district policy/resources. The intensity measure is linked to 3 years of the New York City Youth Risk Behavior Survey (2015, 2017, 2019), and we test the intensity measure in three models sequentially constructed from individual-, school-, and district-level covariates across survey years with district-level fixed effects.

        Results

        We find strong evidence for a relationship between the prevalence of self-reported depressive symptoms and individual and school climate indicators across all years, and document large differences in the prevalence of depressive symptoms and ED utilization by sex.

        Implications for school health policy, practice, and equity

        Within the US context, adolescents spend much of their days in a school environment; our findings suggest that interventions could focus on female adolescents' experiences as well as the school (and district) to improve school climate and depressive symptoms indirectly.
          Cover page: Depressive Symptoms, Emergency Care, and School Climate: An Ecological Analysis of Linked Administrative and Survey Data in New York CityCreative Commons 'BY' version 4.0 license
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