Mediators of Health Communication Intervention and Fruit and Vegetable Consumption among Colon Cancer Survivors living in North Carolina

Background: This study investigated information processing of health communication and mediating effects on fruit and vegetable (F&V) consumption among colon cancer survivors in a population-based randomized trial, the North Carolina Strategies to Improve Diet, Exercise, and Screening project (NC STRIDES). NC STRIDES tested the efficacy of two health communication strategies to promote F&V consumption among a population based sample. A conceptual model was developed to investigate if communication variables such as message relevance, trust, and recall mediated the relationship between tailored health communication and F&V consumption.

Methods: 304 colon cancer survivors come from one of four intervention groups: control, tailored print communication (TPC), tailored telephone-based motivational interviewing (TMI), or combined (TPC+TMI). A path model was constructed to observe the mediation pathway between intervention groups and F&V consumption.

Results: The TPC+TMI intervention was indirectly associated with F&V consumption through perception of message relevance and message trust. The final model fit resulted in (Χ²(17, N=304))=25.50, p=0.08, CFI=0.99, TLI=0.99, and RMSEA=0.041. The TPC+TMI influenced message relevance (β=0.46, p=0.023), and relevance improved message trust (β=0.99, p<0.001). Greater trust improved F&V consumption (β=0.71, p=0.040). Greater trust also improved message recall, but greater recall did not improve F&V consumption. The TPC and TMI alone were not directly associated with F&V consumption.

Conclusions: Determining mediators of cancer communication is important for developing more effective interventions. Further research can investigate ways to enhance message relevance and trust in interventions aimed at colon cancer survivors.