Understanding Mechanisms of Health Behavior

This research seeks to examine psychological factors that may impact relationship between incentives and health behavior engagement, specifically fruit and vegetable consumption. Additionally, it will compare the impact of two different incentive schedules on behavior engagement, one providing immediate rewards (i.e. rewards received on a daily basis) and another providing delayed rewards (i.e. rewards received at the end of the study period), with a control condition in which no rewards are offered. Study participants will provide reports of their fruit and vegetable consumption each day for three weeks, and in the two incentive conditions, they will receive small monetary rewards for their fruit and vegetable consumption. Following the three week reporting and reward period, participants will complete two additional assessments, measuring psychological constructs and behavior engagement following the cessation of rewards.

Study Overview

• Status: Completed
• Conditions: Fruit and Vegetable Consumption; Incentive Interventions
• Intervention / Treatment: Behavioral: Self monitoring; Behavioral: Monetary incentives

• Study Type: Interventional
• Enrollment (Actual): 61
• Phase: Not Applicable

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Consume fewer than 5 servings/day of fruits and vegetables
• Daily access to internet for 3 weeks following baseline session
• Have or are willing to create an account on PayPal

Exclusion Criteria:

-

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Control; Daily reporting of fruit and vegetable consumption	Behavioral: Self monitoring
Experimental: Daily reward; Incentives for fruit and vegetable consumption delivered daily	Behavioral: Self monitoring; Behavioral: Monetary incentives
Experimental: Delayed reward; Incentives for fruit and vegetable consumption delivered in a lump sum at the end of the intervention	Behavioral: Self monitoring; Behavioral: Monetary incentives

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Fruit and Vegetable Consumption, servings per week	3 weeks
Perceived Behavioral Control scale score	3 weeks
Attitudes scale score	3 weeks
Intrinsic Motivation scale score	3 weeks
Fruit and vegetable consumption, servings per week	5 weeks
Perceived Behavioral Control scale score	5 weeks
Attitudes scale score	5 weeks
Intrinsic Motivation scale score	5 weeks

Secondary Outcome Measures

Outcome Measure	Time Frame
Perceived Stress Scale score	3 weeks
Perceived Stress Scale score	5 weeks

Collaborators and Investigators

• Sponsor: University of Colorado, Boulder

Publications and helpful links

General Publications

• Gardiner CK, Bryan AD. Monetary Incentive Interventions Can Enhance Psychological Factors Related to Fruit and Vegetable Consumption. Ann Behav Med. 2017 Aug;51(4):599-609. doi: 10.1007/s12160-017-9882-4.

Study record dates

Study Major Dates

• Study Start: February 1, 2015
• Primary Completion (Actual): June 1, 2015
• Study Completion (Actual): June 1, 2015

Study Registration Dates

• First Submitted: October 30, 2015
• First Submitted That Met QC Criteria: October 30, 2015
• First Posted (Estimated): November 3, 2015

Study Record Updates

• Last Update Posted (Actual): August 1, 2023
• Last Update Submitted That Met QC Criteria: July 27, 2023
• Last Verified: July 1, 2023

More Information

Terms related to this study

• Other Study ID Numbers: 14-0684