Cancer Control Research5R01CA105832-05
Friedman, Robert H.
TRIAL OF 2 TELECOMPUTER DIET CHANGE MAINTENACE PROGRAMS
Health behavior change interventions have focused on obtaining short-term intervention effects; few studies have evaluated mid-term and long-term outcomes, and even fewer have evaluated interventions that are designed to maintain and enhance initial intervention effects. Moreover, behavior theory has not been developed for maintenance or applied to maintenance intervention design to the degree that it has for behavior change initiation. Finally, for both the initiation and maintenance of important health-related behavior, there is a need for population-based interventions that combine the effectiveness of face-to-face professional intervention and the reach of mass-media programs. This may be achieved by telecommunications technology-based interventions that are based on appropriate behavior change theory and the heuristics of trained professionals. The aim of the present proposal is to adapt and evaluate a totally automated, telephone-based dietary behavior change intervention that has been shown to be efficacious in a previous study to the maintenance of dietary change. The study will focus on reducing cancer risk by increasing consumption of fruits and vegetables (F&V) and improving overall diet quality. A representative sample of 1531 adults from a large urban area will be recruited through random digit dialing to participate in a 2-arm RCT with assignment to an efficacious automated dietary behavior change program (Telephone- Linked Care for Diet or TLC-DIET) based on SCT and Goal Setting Theory or to an assessment only control condition. Those participants who respond to the intervention (increase their daily consumption of F&V by > 1 serving) (n=405) will be randomly assigned to one of 3 arms: (1) an assessment only control condition, (2) a maintenance intervention based on SCT and Goal Setting Theory (TLC-EAT.Extended [TCL-EAT.EXT], and (3) a maintenance intervention based on a novel theory (Goal Systems Theory [GST]) (TLC-EAT.Goal Management [TLC-EAT.GM]). GST focuses on the management of other life goals such that the targeted "new" goal (specific dietary behavior) is protected and enhanced. The maintenance interventions will last for 6 months, following by 18 months of observation. All groups are assessed at baseline, 3, 6, 9, 12, 15, 18, and 24 months. The study hypotheses are (1) TLC-EAT.GM > TLC-EAT.EXT > Control at all follow-up time points for F&V consumption and overall diet quality, and (2) intervention effects will be mediated by behavioral factors predicted by SCT (self-efficacy, etc.) and GST (goal shielding, etc.).