Designing Food Voucher Programs to Reduce Disparities in Healthy Diets

NCT02843178 | Completed Results DMC

• 1 other identifier: 36763
• Study Type: interventional
• Target: 359
• Locations: 1 country
• Sites: 1

Brief Summary

Improving diets through increased food and vegetable (F\&V) consumption significantly reduces the risk of cardiovascular disease (CVD). Programs increasing the accessibility and affordability of F\&Vs among low-income Americans have been hindered by the food consumption cycle associated with poverty: the tendency to over-consume calories shortly after receiving funds at the beginning of each month, draining the budget for F\&V purchases, or for all food purchases, by month's end. An emerging theory about dietary behavior suggests that providing funds for food in smaller installments distributed throughout the month will smooth the consumption cycle and improve healthy eating-counteracting the tendency to respond to lump sum, once-monthly funding installments by purchasing calorie-dense foods immediately after funds are received. The theory also suggests that funds targeted toward specific healthy foods (e.g., F\&Vs) will improve diets more than untargeted funds, despite the inconvenience of utilizing targeted funds. We will rigorously test both hypotheses in a real-world setting by comparing alternative approaches for delivering food purchasing vouchers. We have established and tested the infrastructure to provide vouchers accepted by numerous food sellers (e.g., supermarkets, corner shops) in low-income neighborhoods. Leveraging this infrastructure, we will conduct a randomized trial with a two-by-two factorial design, comparing $20 of vouchers valid for one month to four $5 vouchers each valid for a sequential week of the month (lump sum versus distributed funding), and comparing vouchers restricted to F\&V purchases to vouchers redeemable for any food (targeted versus untargeted funding). Low-income adults (N=288) recruited through our community partners will be randomized to one of four 6-month interventions: monthly targeted, monthly untargeted, weekly targeted, or weekly untargeted vouchers. Participants will be assessed through efficient verbal 24-hour dietary recalls validated among low-literacy populations, to determine daily consumption of F\&Vs and metrics of overall dietary quality at months 0, 6 and 12 (6 months after vouchers end). Additional surveys will identify moderators and mediators of dietary improvement.

Conditions

Cardiovascular Diseases

Keywords

nutrition; food security; behavioral economics

Outcome Measures

Primary Outcomes (1)

• Change in Cup-equivalents of Fruit and Vegetable Intake From Baseline to Month 6

  Fruit and vegetable intake (measured in Cup-equivalents) at the end of month 6 of the trial, assessed by 24-hour dietary recall

  Baseline and Month 6

Secondary Outcomes (3)

• Change in Cup-equivalents of Fruit and Vegetable Intake From Baseline to Month 12

  Baseline and Month 12

• Change in Healthy Eating Index From Baseline to Month 6

  Baseline and Month 6

• Voucher Utilization Rate

  Months 1-6 of intervention

Other Outcomes (4)

• Voucher Ease of Use Survey

  Month 6

• Self-reported Height Survey

  Month 6

• Food Security Survey

  Baseline, Month 6, and Month 12

Study Arms (4)

1: distributed, targeted vouchers

EXPERIMENTAL

Participants receive four $5 vouchers each valid for a subsequent week of the month (i.e., one voucher valid for week 1 only, a second for week 2 only, a third for week 3 only, and a fourth for week 4 only), starting in month 1 and continuing every month through month 6. The voucher is restricted to pay for fruits and vegetables.

Behavioral: Vouchers

2: lump sum, targeted vouchers

ACTIVE COMPARATOR

Participants receive four $5 vouchers each valid for an entire month, starting in month 1 and continuing every month through month 6. The voucher is restricted to pay for fruits and vegetables.

Behavioral: Vouchers

3: distributed, untargeted vouchers

ACTIVE COMPARATOR

Participants receive four $5 vouchers each valid for a subsequent week of the month (i.e., one voucher valid for week 1 only, a second for week 2 only, a third for week 3 only, and a fourth for week 4 only), starting in month 1 and continuing every month through month 6. The voucher can pay for any food but not tobacco, alcohol or prepared foods.

Behavioral: Vouchers

4: lump sum, untargeted vouchers

ACTIVE COMPARATOR

Participants receive four $5 vouchers each valid for an entire month, starting in month 1 and continuing every month through month 6. The voucher can pay for any food but not tobacco, alcohol or prepared foods.

Behavioral: Vouchers

Interventions

Vouchers BEHAVIORAL

A voucher is given that can be used at the cashier of participating grocery stores, corner stores, and farmer's markets, enabling a participant to have the voucher's value subtracted from their grocery bill.

1: distributed, targeted vouchers; 2: lump sum, targeted vouchers; 3: distributed, untargeted vouchers; 4: lump sum, untargeted vouchers

Eligibility Criteria

• Age: 21 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

Sponsors & Collaborators

• Stanford University: lead
• University of California, San Francisco: collaborator
• University of California, Irvine: collaborator

Study Sites (1)

CHIVES Study Office

San Francisco, California, 94124, United States

Location

Related Publications (4)

• White JS, Basu S. Does the benefits schedule of cash assistance programs affect the purchase of temptation goods? Evidence from Peru. J Health Econ. 2016 Mar;46:70-89. doi: 10.1016/j.jhealeco.2016.01.005. Epub 2016 Jan 29.

  PMID: 26874596 BACKGROUND

• Whittle HJ, Palar K, Hufstedler LL, Seligman HK, Frongillo EA, Weiser SD. Food insecurity, chronic illness, and gentrification in the San Francisco Bay Area: An example of structural violence in United States public policy. Soc Sci Med. 2015 Oct;143:154-61. doi: 10.1016/j.socscimed.2015.08.027. Epub 2015 Aug 20.

  PMID: 26356827 BACKGROUND

• Seligman HK, Bolger AF, Guzman D, Lopez A, Bibbins-Domingo K. Exhaustion of food budgets at month's end and hospital admissions for hypoglycemia. Health Aff (Millwood). 2014 Jan;33(1):116-23. doi: 10.1377/hlthaff.2013.0096.

  PMID: 24395943 BACKGROUND

• Basu S, Gardner CD, White JS, Rigdon J, Carroll MM, Akers M, Seligman HK. Effects Of Alternative Food Voucher Delivery Strategies On Nutrition Among Low-Income Adults. Health Aff (Millwood). 2019 Apr;38(4):577-584. doi: 10.1377/hlthaff.2018.05405.

  PMID: 30933599 RESULT

MeSH Terms

Conditions

Cardiovascular Diseases

Limitations and Caveats

Dietary data are from self-report, via 24-hour dietary recalls. Survey data are from self-reported scales.

Results Point of Contact

• Title: Mandy Murphy Carroll, Study Coordinator
• Organization: Stanford University

mandyiam@stanford.edu

(650) 509-0004

Study Officials

• Sanjay Basu, MD, PhD

  Stanford University

  PRINCIPAL INVESTIGATOR

• Hilary K Seligman, MD, MS

  University of California, San Francisco

  PRINCIPAL INVESTIGATOR

• Christopher D Gardner, PhD

  Stanford University

  PRINCIPAL INVESTIGATOR

Publication Agreements

• PI is Sponsor Employee: No
• Restrictive Agreement: No

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: PREVENTION
• Intervention Model: FACTORIAL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Professor of Medicine

Study Record Dates

• First Submitted: July 20, 2016
• First Posted: July 25, 2016
• Study Start: December 1, 2016
• Primary Completion: October 9, 2018
• Study Completion: October 9, 2018
• Last Updated: August 28, 2019
• Results First Posted: August 28, 2019

Record last verified: 2019-07

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)