Degree Name

PhD (Doctor of Philosophy)



Date of Award


Committee Chair or Co-Chairs

Jameson K. Hirsch

Committee Members

Julia Dodd, Kelly Moore, Alyson Chroust


Among persons living with, or recovering from, chronic illness, poor physical health-related quality of life is a concern, as current and residual illness symptoms and treatment side effects may deleteriously impact physical functioning and fulfillment of daily roles. Numerous cognitive, emotional, and behavioral factors may impact perceptions of health status. Optimism, for example, is conceptualized as belief in the occurrence of positive future outcomes, and is beneficially associated with physical health-related quality of life. Further, optimism may contribute to enhanced perceptions of control and efficacy over disease symptoms and general health, manifesting as proactive health behaviors (e.g., wellness behaviors; treatment adherence) and, in turn, improved health-related quality of life. Across independent samples of persons living with remitted cancer (N = 164) or fibromyalgia (N = 508), we examined the serial mediating effects of health-related self-efficacy and proactive health behaviors in the relation between dispositional optimism and physical health-related quality of life. Participants completed online self-report measures, including the Life Orientation Test – Revised, Control Beliefs Inventory, Multidimensional Health Profile – Health Functioning Index, Wellness Behaviors Inventory, Medical Outcomes Study General Treatment Adherence Scale, and the Short-Form Health Survey. Significant serial mediation was observed across samples; higher dispositional optimism was associated with greater health-related self-efficacy and, in turn, greater engagement in proactive health behaviors and better physical health-related quality of life. For persons with remitted cancer, absence of other specific indirect effects indicates a need to consider the potential impact of unique aspects of disease, such as late effects of treatment or fear of recurrence, that may limit the beneficial effects of optimism exclusively through health-related self-efficacy or wellness behaviors. For persons with fibromyalgia, we found specific indirect effects through each mediating variable, lending support for the decoupling of cognitive and behavioral factors, consistent with pathophysiological and psychosomatic explanations of illness symptoms and approaches to treatment. Interventions designed to enhance optimism (e.g., cognitive-behavioral therapy; best possible self exercise) or self-efficacy (e.g., exercise skills training) may have positive downstream effects on health behavior engagement and perceptions of physical health-related quality of life among individuals living with remitted cancer or fibromyalgia.

Document Type

Dissertation - unrestricted


Copyright by the authors.