Diet and exercise intervention adherence and health-related outcomes among older long-term breast, prostate, and colorectal cancer survivors

Abstract

Background: Diet and exercise interventions for cancer survivors result in health benefits; however, few studies have examined health outcomes in relation to adherence.

Purpose: We examined associations between adherence to components of a diet-exercise intervention and survivors' physical and mental health.

Methods: A randomized controlled trial tested a telephone and mailed print intervention among 641 older, overweight, long-term survivors of breast, prostate, and colorectal cancer. Dietary and exercise behaviors were assessed at 14 time points throughout the year-long intervention; health outcomes were examined postintervention.

Results: Telephone session attendance had significant indirect relationships with health outcomes through intervention-period exercise and dietary behavior. Attendance showed positive indirect relationships with physical function (β = 0.11, p < 0.05), basic and advanced lower extremity function (β = 0.10, p < 0.05/β = 0.09, p < 0.05), and mental health (β = 0.05, p < 0.05), and a negative indirect relationship with body mass index (β = -0.06, p < 0.05).

Conclusions: Session attendance is vital in facilitating improvement in health behaviors and attendant outcomes (Clinicaltrials.gov number NCT00303875).

Conflict of interest statement

Authors’ Statement of Conflict of Interest and Adherence to Ethical Standards Authors Joseph G. Winger, Catherine E. Mosher, Kevin L. Rand, Miriam C. Morey, Denise C. Snyder, and Wendy Demark-Wahnefried declare that they have no conflict of interest. All procedures, including the informed consent process, were conducted in accordance with the ethical standards of the responsible committee on human experimentation (institutional and national) and with the Helsinki Declaration of 1975, as revised in 2000.

Figures

Fig. 1

Proposed conceptual model depicting the relationship between adherence to the RENEW diet and exercise intervention and health-related outcomes

Fig. 2

Test of proposed conceptual model depicting the relationship between adherence to the RENEW diet and exercise intervention and health-related outcomes. Gender, age, education, and number of comorbidities were included in each of the pathways as covariates. Although not depicted in the figure, all mediators (i.e., strength and endurance exercise, fruit and vegetable intake, and saturated fat intake) and outcomes were allowed to covary. Paths are depicted with standardized regression coefficients significant at p<0.05; nonsignificant paths are not depicted. χ2 (5, N=641)=5.55, p=0.35, RMSEA=0.01, 90% confidence interval (0.00, 0.06)