Qian Huang

Date of Award

Fall 2022

Document Type

Open Access Dissertation



First Advisor

Susan L. Cutter


COVID-19 has caused significant social, economic, environmental, and political impacts globally and affected communities unequally in the U.S. The pandemic has also sparked interest in age-specific manifestations of infection, for example, studies confirmed the risk of increasing age with COVID-19 severity. However, the nonstationarity effects of health determinants among age groups have not been well examined. This study aims to explore the nonstationarity effects of social, behavioral, environmental, health care access, and political contexts on COVID-19 outcomes. This study poses three broad questions: 1) how did COVID-19 vaccinations align with COVID-19 daily cases and deaths in the United States; 2) given the overall spatial distribution of COVID-19 exposures, what are the differences based on age (children, adults, and older adults), and what are the driving factors of these differences; and 3) among older adults age 60-79 and older adults age 80 and over, are there differences in exposures to COVID-19, and what is the spatial variability in the driving factors producing such outcomes?

To address the research questions, this study examined the spatial and temporal patterns of the relationships between the county-level COVID-19 daily new cases, fatalities, and full vaccinations in the United States. The different effects of health determinants among urban/rural areas confirmed the spatial nonstationarity. Moreover, this dissertation proposed a new type of nonstationarity: age nonstationarity which means health effects of contextual variables vary among age groups. Based on this theory, the study created a community-based COVID-19 spatial disparity model. Specifically, Chapter 3 selected 62 county-level variables for U.S. counties and created an adjustable COVID-19 Exposure Index (ACOVIDPEI) using principal component analysis. In addition, Chapter 4 explored differences in COVID-19 exposures within the older adult group and its driving factors. This dissertation not only extended the evidence of urban-rural disparities in the relationship between COVID-19 outcomes and vaccinations in the U.S., but also affirmed the health determinants’ nonstationarity effect among age groups. This means that varied sociodemographic and contextual factors influence COVID-19 exposure risk among different age groups at varying time-periods during the pandemic. This work helps engage others in conversations about the problems and solutions, guide efforts to promote programs and policies for change, and help local governments and organizations address health disparities in their communities.


© 2022, Qian Huang

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