Change in self-efficacy partially mediates the effects of the FRESH START intervention on cancer survivors' dietary outcomes

Abstract

Objective: This study examined change in self-efficacy as a mediator of the effects of a mailed print intervention on the dietary and exercise practices of newly diagnosed breast and prostate cancer survivors.

Method: A total of 543 breast and prostate cancer patients were recruited from 39 states and two provinces within North America. Participants were randomly assigned to receive a 10-month program of tailored mailed print materials that aimed to increase fruit and vegetable consumption, reduce fat intake, and/or increase exercise or a 10-month program of publically available materials on diet and exercise. Telephone surveys conducted at baseline and 1 year assessed dietary practices, physical activity, and self-efficacy for engaging in these health behaviors.

Results: Results indicated that changes in self-efficacy for fat restriction and eating more fruits and vegetables were significant mediators of the intervention's effects on dietary outcomes at 1-year follow-up. The intervention did not significantly affect self-efficacy for exercise; however, a significant, positive relationship was found between self-efficacy for exercise and exercise duration at follow-up.

Conclusions: Findings are largely consistent with Social Cognitive Theory and support the use of strategies to increase self-efficacy in health promotion interventions for cancer survivors.

Conflict of interest statement

Authors’ Disclosures of Potential Conflicts of Interest

The authors indicated no potential conflicts of interest.

Copyright (c) 2008 John Wiley & Sons, Ltd.

Figures

Figure 1

Model depicting the effects of intervention condition (coded 0 = attention control, 1 = FRESH START intervention) on diet quality and mediators, adjusting for baseline mediator and dependent variables. Unstandardized regression coefficients are shown outside of the parentheses, and standardized coefficients are reported in the parentheses. F&V = fruits and vegetables. *p < .05. **p < .01. ***p < .001.

Figure 2

Figures 2a–c. Model depicting the effects of intervention condition (coded 0 = attention control, 1 = FRESH START intervention) on exercise and dietary outcomes and mediators, adjusting for baseline mediator and dependent variables. Unstandardized regression coefficients are shown outside of the parentheses, and standardized coefficients are reported in the parentheses. F&V = fruits and vegetables. **p < .01. ***p < .001.