Testing a theoretical model of perceived self-efficacy for cancer-related fatigue self-management and optimal physical functional status

Abstract

Background: Critical gaps exist in the understanding of cancer symptoms, particularly for cancer-related fatigue (CRF). Existing theories and models do not examine the key role perceived self-efficacy (PSE) plays in a person's ability to manage symptoms.

Objectives: The objective of this study was to test the hypothesis that physical functional status (PFS) is predicted through patient characteristics, CRF, other symptoms, and PSE for fatigue self-management in persons with cancer.

Methods: This study is a secondary data analysis from the baseline observation of two randomized control trials. The combined data set includes 298 participants who were undergoing a course of chemotherapy. Key variables included physiological and contextual patient characteristics, the severity from CRF and other symptoms, PSE, and PFS. Path analysis examined the relationships among the variables in the proposed theoretical model.

Results: Persons with cancer reported CRF as the most prevalent symptom among a mean of 7.4 other concurrent symptoms. The severity from CRF had a direct and indirect effect on PFS, with CRF having a direct adverse impact on PFS (t = -7.02) and an indirect adverse effect as part of the severity from the other symptoms (t = 9.69), which also adversely impacted PFS (t = -2.71). Consistent with the proposed theoretical model, PSE had a positive effect on the PFS (t = 2.87) of persons with cancer while serving as a mediator between CRF severity and PFS.

Discussion: Cancer-related fatigue is prevalent and related to the presence of other symptoms, and PSE for fatigue self-management is an important factor influencing CRF and PFS. A foundation is provided for future intervention studies to increase PSE to achieve optimal PFS in persons with cancer.

Figures

Figure 1

Hypothesized Theoretical Model

1. Asterisk (*) means there are more than one variable in certain patient characteristic categories. See details of each patient characteristic in the Measures Section of the manuscript.

2. Dashed line means the relationship between perceived self-efficacy for fatigue self-management and symptom self-management behaviors is an untested assumption of the theoretical framework and assessing symptom self-management behaviors was beyond the scope of this study.

Figure 2

Final Parsimonious Theoretical Model: Satorra-Bentler Scaled Chi-Square 17.76; p = .22; df = 14; RMSEA = .03; RMSEA lower bound 90% CI = 0.00; RMSEA upper bound 90% CI = 0.068; CFI = .99; GFI = 0.99; and AIC 79. • Solid line means a significant direct path (t > -/+ 2.0). • Dashed line means a nonsignificant direct path (t < 2.0). • The numerical values represent standardized path coefficients. • Not depicted in the Figure 2, standardized significant indirect path coefficient from CRF severity to PFS of -0.14.