The EValuating Interventions in Diabetogenic Environments Through Natural Controlled Experiments (EVIDENCE) Trial
Overview
- Phase
- Not Applicable
- Intervention
- Not specified
- Conditions
- Cardiovascular Diseases
- Sponsor
- Stanford University
- Enrollment
- 313
- Locations
- 2
- Primary Endpoint
- Change in fruit and vegetable consumption
- Status
- Completed
- Last Updated
- 5 years ago
Overview
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.
Investigators
Christopher Gardner
Assistant Professor of Medicine
Stanford University
Eligibility Criteria
Inclusion Criteria
- •Understand English sufficiently to provide informed consent;
- •Provision of signed and dated informed consent form;
- •Stated willingness to comply with all study procedures and availability for the duration of the study;
- •Any gender, aged 21 years or older;
- •Have self-reported income ≤250% of the federal poverty level;
- •Have regular access to a mobile phone;
- •Have a safe and secure mailing address at which to receive vouchers;
- •Be a resident of the Counties of San Francisco or Los Angeles as defined by official municipal boundaries.
Exclusion Criteria
- •Currently participating in any other dietary or nutrition study that would impact his or her normal eating patterns;
- •Currently be enrolled in and receiving EatSF, CHIVES, or Vouchers4Veggies vouchers;
- •Has active diagnosis of cancer or congestive heart failure;
- •Is planning to move out of San Francisco or Los Angeles in the next 12 months;
- •Currently pregnant.
- •Currently live with and share a food budget with a current Vouchers4Veggies, EVIDENCE, or CHIVES study participant.
Outcomes
Primary Outcomes
Change in fruit and vegetable consumption
Time Frame: 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 Outcomes
- Change in SSB consumption(Month 0 to Month 6)
- Change in nutrition quality per HEI score(Month 0 to Month 6)
- Overall percentage of vouchers redeemed(Month 0 to Month 6)
- Change in nutrition quality per AHEI score(Month 0 to Month 6)
- Change in overall caloric intake(Month 0 to Month 6)