Fatigue, Self-efficacy, Physical Activity, and Quality of Life in Women With Breast Cancer

Background: More than 192 000 US women faced the challenge of living with breast cancer in 2009. Although exercise may help combat treatment-related symptoms, cancer-related fatigue has been identified as a potential barrier to engaging in physical activity. Self-efficacy has been proposed to mediate the impact of cancer-related fatigue on physical activity and subsequently improve quality of life (QOL). Objective: The purpose of this study was to determine the linkages among the concepts of an introductory model of fatigue related to cancer, self-efficacy for physical activity, physical activity, and QOL in women being treated for breast cancer. Interventions/Methods: Women currently receiving treatment for breast cancer were asked to complete 5 instruments: demographic profile, Piper Fatigue Scale, Physical Activity Assessment Inventory, Human Activity Profile, and McGill QOL Questionnaire. Structural equation modeling of the data was performed to determine the direct and indirect influences of study variables on QOL. Results: The model was tested based on responses of 73 participants. All paths between variables were significant. The model explained 53% of the variance in QOL scores, 28% of the variance in physical activity, and 31% of the variance in self-efficacy. Conclusions: Although fatigue is most commonly thought of as a physical problem requiring physical intervention, this study provides emerging evidence to suggest there may be potential interventions to improve self-efficacy that may mediate the effect of fatigue on QOL. Implications for Practice: Interventions to improve self-efficacy may contribute to increased physical activity and improved QOL in this population.