Trial of 2 TeleComputer Diet Change Maintenance Programs

Trial of 2 TeleComputer Diet Change Maintenance Programs

Principal Investigator: Robert H. Friedman, M.D.

Boston Medical Center

Abstract:

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.).

Specific Aims:

This proposed study will evaluate the effectiveness of two totally automated interventions for maintaining previously achieved improvements in dietary behaviors related to the primary prevention of cancer, as compared to each other and to an assessment-only comparison group. The study consists of two linked randomized clinical trials (RCTs). In the first trial, the “behavioral change acquisition study,” subjects who consume less than recommended levels of fruits and vegetables (F&V) will use an automated, telephone-based intervention for 6 months, designed to increase their consumption of F&V and improve their overall diet quality. This intervention, called Telephone-Linked Care for Eating (TLC-EAT), has been shown to be efficacious in a previous RCT (see Section C.2). Those subjects in the first trial who have a positive response to the TLC-EAT intervention (increase their consumption of F&V by >1 serving/day), will enter the second trial, the “behavior change maintenance study”. They will be randomly assigned to one of two dietary behavior change maintenance interventions based on TLC-EAT for 6 months, or to a control condition.

The 3 interventions (TLC-EAT and the 2 maintenance interventions) will use a telecommunications technology called Telephone-Linked Care, or TLC, which has successfully been used to promote behavior change for a variety of health-related behaviors in many populations. Each intervention is structured by behavior theory. TLC-EAT uses Social Cognitive Theory (SCT) and Goal Setting Theory. One of the two TLC behavior maintenance interventions (TLC-EAT. Extended or TLC-EAT.EXT) uses SCT and goal setting to focus on long-term maintenance, whereas the other maintenance intervention (TLC-EAT. Goal Management or TLC-EAT.GM) uses a novel theory, Goal Systems Theory (GST), to structure a dietary behavior maintenance intervention. The major innovation of this theory is to focus the intervention on the management of other life goals in such a way that dietary behavior goals established during the TLC-EAT “acquisition” intervention are protected and enhanced. To our knowledge, this is both a novel application of this theory and a novel theoretical approach to health behavior change maintenance.

The specific aims of this project are to:

Modify an interactive computer telephony intervention (TLC-EAT) to create two different versions (TLC-EAT.EXT and TLC-EAT.GM), each based on different behavior theories, to promote the long-term maintenance of healthy eating behaviors.
In a three-arm randomized clinical trial, compare the effectiveness of the two interventions, TLC-EAT.EXT and TLC-EAT.GM, to an assessment-only condition and to each other in the maintenance of increased fruit and vegetable consumption.
Systematically measure and explore the phenomena of the maintenance of dietary behavior change to add to the understanding of the subject, as well as to evaluate the validity of the theoretical approaches that are the bases of the tested interventions.