Fruit and Vegetable Vouchers With and Without an SSB Tax

Not Applicable

Completed

• Conditions: Cardiovascular Diseases
• Interventions: Behavioral: Fruit and vegetable voucher

• Registration Number: NCT03567967
• Lead Sponsor: Stanford University

Brief Summary

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).

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 Timeline

• Study Start: 2018-05-31
• Study First Submitted: 2018-05-31
• Study First Submitted QC: 2018-06-21
• Study First Posted: 2018-06-26
• Primary Completion: 2019-09-09
• Study Completion: 2019-09-09
• Status Verified: 2020-07
• Last Update Submitted: 2020-07-15
• Last Update Posted: 2020-07-17

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 313

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.

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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.

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Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Los Angeles	Fruit and vegetable voucher	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.
San Francisco	Fruit and vegetable voucher	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.

Primary Outcome Measures

Name	Time	Method
Change in fruit and vegetable consumption	Month 0 to Month 6	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).

Secondary Outcome Measures

Name	Time	Method
Change in overall caloric intake	Month 0 to Month 6	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).
Change in SSB consumption	Month 0 to Month 6	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).
Change in nutrition quality per HEI score	Month 0 to Month 6	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).
Overall percentage of vouchers redeemed	Month 0 to Month 6	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.
Change in nutrition quality per AHEI score	Month 0 to Month 6	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).

Trial Locations

Locations (2)

University of California; 🇺🇸 San Francisco, California, United States

Stanford University; 🇺🇸 Stanford, California, United States