Fruit and Vegetable Vouchers With and Without an SSB Tax (EVIDENCE)

The EValuating Interventions in Diabetogenic Environments Through Natural Controlled Experiments (EVIDENCE) Trial

We aim to examine whether a purchasing incentive for healthy foods has the same effect on dietary intake in a community with and a community without a purchasing penalty for unhealthy foods. We will perform a randomized non-inferiority trial in two locations, San Francisco (SF) and Los Angeles (LA) to test whether a voucher for purchasing fresh fruits and vegetables has a similar effect in LA and in SF, where the former does not but the latter does have a tax on sugar-sweetened beverages. Participants will be recruited from 4 neighborhoods (N=312) with 2 SF neighborhoods (exposed to the SSB tax) and 2 LA neighborhoods (not exposed to the SSB tax).

Study Overview

• Status: Completed
• Conditions: Cardiovascular Diseases
• Intervention / Treatment: Behavioral: Fruit and vegetable voucher

Detailed Description

We will test the hypothesis that a positive incentive for healthy foods (fresh fruits and vegetables, F&Vs) will be utilized as effectively in a community without a purchasing penalty for unhealthy foods (a sugar-sweetened beverage [SSB] tax) as in a community with a purchasing penalty for unhealthy foods (a SSB tax). Our experiment will test the empirically-driven hypothesis in a real-world setting through a noninferiority design: comparing the impact of F&V vouchers in two counties, one without (Los Angeles) and one with (San Francisco) a SSB tax.

Each study participant will receive four paper vouchers per month for a total of six months. Each of these vouchers can be redeemed for fresh or frozen fruits and vegetables at a number of specified local corner stores, supermarkets, or farmer's markets.

Half of these participants will receive and spend these vouchers in an environment which has implemented a SSB tax (SF); the other half will receive and spend these same vouchers in a non-tax environment (LA).

Each individual participant will be enrolled in the study for a total of seven months from initial orientation and participant consent (M0) to final data collection during final month of intervention (M6).

We are using a non-inferiority trial design. We are aiming to test whether there is a significant difference in total cup-equivalents of F&V intake in LA participants as compared to SF participants when given F&V vouchers. That is, we aim to test whether the F&V voucher is less effective in LA than in SF. This is important to test because it has been purported that SF has a unique food environment with high accessibility to fresh F&V through farmer's markets and a plethora of corner stores, as well as a SSB tax that discourages less healthy foods, potentially leaving more funds for healthier F&Vs. Thus, we aim to determine the change in consumption of F&V in LA participants is non-inferiority to that of SF participants, when both are given F&V vouchers.

• Study Type: Interventional
• Enrollment (Actual): 313
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • California
    • San Francisco, California, United States, 94158
      • University of California
    • Stanford, California, United States, 94305
      • Stanford University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 21 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

Description

Inclusion Criteria:

1. Understand English sufficiently to provide informed consent;
2. Provision of signed and dated informed consent form;
3. Stated willingness to comply with all study procedures and availability for the duration of the study;
4. Any gender, aged 21 years or older;
5. Have self-reported income ≤250% of the federal poverty level;
6. Have regular access to a mobile phone;
7. Have a safe and secure mailing address at which to receive vouchers;
8. Be a resident of the Counties of San Francisco or Los Angeles as defined by official municipal boundaries.

Exclusion Criteria:

1. Currently participating in any other dietary or nutrition study that would impact his or her normal eating patterns;
2. Currently be enrolled in and receiving EatSF, CHIVES, or Vouchers4Veggies vouchers;
3. Has active diagnosis of cancer or congestive heart failure;
4. Is planning to move out of San Francisco or Los Angeles in the next 12 months;
5. Currently pregnant.
6. Currently live with and share a food budget with a current Vouchers4Veggies, EVIDENCE, or CHIVES study participant.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: San Francisco; Each study participant will receive four paper vouchers per month for a total of six months. Each of these vouchers can be redeemed for fresh or frozen fruits and vegetables at a number of specified local corner stores, supermarkets, or farmer's markets. The San Francisco participants will receive and spend these vouchers in an environment which has implemented a sugar-sweetened beverage tax.	Behavioral: Fruit and vegetable voucher; Participants will receive four vouchers, each dated for a month, to be used on fruits and vegetables at specified local corner stores, supermarkets, and farmer's markets for a duration of six months. Each study participant will have the same intervention, as this is a non-inferiority trial to compare voucher use in LA and test whether the nutritional effects of that use are non-inferior to use in SF.; Other Names: Voucher
Active Comparator: Los Angeles; Each study participant will receive four paper vouchers per month for a total of six months. Each of these vouchers can be redeemed for fresh or frozen fruits and vegetables at a number of specified local corner stores, supermarkets, or farmer's markets. The Los Angeles participants will receive and spend these vouchers in an environment which has NOT implemented a sugar-sweetened beverage tax.	Behavioral: Fruit and vegetable voucher; Participants will receive four vouchers, each dated for a month, to be used on fruits and vegetables at specified local corner stores, supermarkets, and farmer's markets for a duration of six months. Each study participant will have the same intervention, as this is a non-inferiority trial to compare voucher use in LA and test whether the nutritional effects of that use are non-inferior to use in SF.; Other Names: Voucher

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in fruit and vegetable consumption	Change in fruit and vegetable consumption from baseline (BL), i.e., before voucher receipt, to the end of the intervention at the end of month 6 (M6), i.e., during the final month of voucher receipt, measured by two 24-hour recalls at each data collection point (BL and M6).	Month 0 to Month 6

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in nutrition quality per HEI score	Change in nutrition quality of study participants from BL to M6, measured by the Healthy Eating Index (HEI), which is calculated from two 24-hour recalls at each data collection point (BL and M6).	Month 0 to Month 6
Change in nutrition quality per AHEI score	Change in nutrition quality of study participants from BL to M6, measured by the Alternative Healthy Eating Index (AHEI), which is calculated from two 24-hour recalls at each data collection point (BL and M6).	Month 0 to Month 6
Change in SSB consumption	Change in SSB consumption from BL to M6, measured in change in fluid ounces, as measured by two 24-hour recalls at each data collection point (BL and M6).	Month 0 to Month 6
Change in overall caloric intake	Change in overall caloric intake from BL to M6, measured in change in kcal, as measured by two 24-hour dietary recalls at each data collection point (BL and M6).	Month 0 to Month 6
Overall percentage of vouchers redeemed	Overall percentage of vouchers redeemed per participant, measured by how many vouchers each participant redeemed as compared to how many vouchers they received over the 6 month intervention period.	Month 0 to Month 6

Collaborators and Investigators

• Sponsor: Stanford University
• Collaborators: University of California, San Francisco
• Investigators: Principal Investigator: Dean Schillinger, MD, University of California, San Francisco; Principal Investigator: Sanjay Basu, MD, PhD, Assistant Professor of Medicine

Publications and helpful links

Helpful Links

• San Francisco program
• Los Angeles program

Study record dates

Study Major Dates

• Study Start (Actual): May 31, 2018
• Primary Completion (Actual): September 9, 2019
• Study Completion (Actual): September 9, 2019

Study Registration Dates

• First Submitted: May 31, 2018
• First Submitted That Met QC Criteria: June 21, 2018
• First Posted (Actual): June 26, 2018

Study Record Updates

• Last Update Posted (Actual): July 17, 2020
• Last Update Submitted That Met QC Criteria: July 15, 2020
• Last Verified: July 1, 2020

More Information

Terms related to this study

• Keywords: nutrition; sugar-sweetened beverages; fruits and vegetables
• Additional Relevant MeSH Terms: Cardiovascular Diseases
• Other Study ID Numbers: 43831

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No