Fatigue, self-efficacy for physical activity, physical activity, and quality of life in women with breast cancer

This descriptive correlational study was conducted to examine the direct and indirect influences of fatigue, self-efficacy for physical activity, and physical activity on quality of life (QOL) in women with breast cancer. Relationships among these variables were compared between women with breast cancer and a comparison group of women. A theoretical model, philosophically congruent with a health within illness perspective and generated by integrating selected concepts from Pender’s Health Promotion Model and Bandura’s Social Cognitive Theory, was used to guide the study. Instruments used to measure study concepts included the Piper Fatigue Scale to evaluate fatigue; a researcher developed Physical Activity Assessment Inventory to measure self-efficacy for physical activity; the Human Activity Profile to calculate physical activity; and the McGill QOL Questionnaire to assess QOL. Participants (n =128) included 73 women receiving either chemotherapy or hormonal therapy for any stage breast cancer and 55 women in a comparison group with no history of cancer. The participants were primarily Caucasian, educated, and married. Correlational analyses suggested moderately strong relationships among the research model variables (fatigue, self-efficacy for physical activity, physical activity, and QOL) for both groups of women. There was an inverse relationship between fatigue scores and the scores for self-efficacy for physical activity, physical activity, and QOL. There was a direct relationship among the scores for self-efficacy for physical activity, physical activity, and QOL. Women receiving treatment for breast cancer reported higher levels of fatigue and lower levels of self-efficacy for physical activity and physical activity than women in the comparison group did. There was no difference in QOL scores between the groups. Results from path analysis supported the research model, explaining 53% of the variance in QOL scores. Fatigue has direct and indirect influences on QOL that are partially mediated by self-efficacy for physical activity and physical activity. Self-efficacy for physical activity directly influences physical activity, which then directly influences QOL. This research provides knowledge to help guide nursing care of women receiving treatment for breast cancer. Continued research and refinement of the model is required to determine additional influences of QOL in women receiving treatment for breast cancer.