Clinical trial NCT03567967: Fruit and Vegetable Vouchers With and Without an SSB Tax
Official title: The EValuating Interventions in Diabetogenic Environments Through Natural Controlled Experiments (EVIDENCE) Trial
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Cardiovascular Diseases
Keywords: nutrition
fruits and vegetables
sugar-sweetened beverages
Lead sponsor: Stanford University
Sponsor class: OTHER
Collaborators: name: University of California, San Francisco
First posted: 2018-06-26
Enrollment: 313
Sex: ALL
Minimum age (years): 21
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: PREVENTION

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.

Eligibility criteria: 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.

Primary outcomes:
measure: Change in fruit and vegetable consumption
timeFrame: Month 0 to Month 6
Secondary outcomes:
measure: Change in nutrition quality per HEI score
timeFrame: Month 0 to Month 6
measure: Change in nutrition quality per AHEI score
timeFrame: Month 0 to Month 6
measure: Change in SSB consumption
timeFrame: Month 0 to Month 6
measure: Change in overall caloric intake
timeFrame: Month 0 to Month 6
measure: Overall percentage of vouchers redeemed
timeFrame: Month 0 to Month 6
Other outcomes:
Locations:
city: San Francisco
country: United States
facility: University of California
state: California
city: Stanford
country: United States
facility: Stanford University
state: California
Study officials:
affiliation: Assistant Professor of Medicine
name: Sanjay Basu, MD, PhD
role: PRINCIPAL_INVESTIGATOR
affiliation: University of California, San Francisco
name: Dean Schillinger, MD
role: PRINCIPAL_INVESTIGATOR
References: