Designing Food Voucher Programs to Reduce Disparities in Healthy Diets

摘要 通过增加食物和蔬菜（F&V）消费来改善饮食，可显著降低心血管疾病（CVD）的风险。提高低收入人群获得F& V的机会和负担能力的方案 美国人受到与贫困相关的食品消费周期的阻碍：倾向于 在每个月初收到资金后不久就过度消耗卡路里，耗尽预算， F&V采购，或所有食品采购，到月底。仅仅增加粮食援助资金并不能 解决这个问题，但一个关于饮食行为的新兴理论表明， 在整个月分发的小额分期付款将平滑消费周期， 健康的饮食-抵消倾向，以应对一次性，每月一次的资金分期付款， 在收到资金后立即购买高热量食品。该理论还表明，针对特定健康食品的资金（例如，F& V）将改善饮食比非目标资金，尽管在- 使用目标资金的便利。我们的初步数据支持这两种假设，我们将在现实世界中通过比较提供食品购买券的替代方法来严格测试。 我们已经建立并测试了基础设施，以提供所有主要食品商店都接受的代金券（例如， 超市，街角商店）在两个低收入社区。利用这种创新的基础设施， 目的1：我们提出了一个随机试验，采用2 × 2析因设计，比较20美元的代金券有效期为 一个月至四张5美元的代金券，每张代金券在当月的连续一周内有效（一次总付与分发 资金），并将仅限于F&V购买的代金券与可兑换任何食品的代金券进行比较（针对 与无针对性的供资相比）。通过我们的社区合作伙伴招募的低收入成年人（N=288）将被随机分配到四个为期6个月的干预措施之一：每月有针对性的，每月无针对性的，每周有针对性的，或每周无针对性的代金券。参与者将通过有效的口头24小时饮食回忆进行评估， 在低文化程度的人群中，确定F& V的每日消费量和整体饮食质量的指标 在第0、6和12个月（凭单结束后6个月）。其他调查将确定主持人和调解人 改善饮食的方法。在目标2中，我们将计算代金券计划的成本效益。券 和其他支持健康饮食的干预措施减少了人口水平的CVD差异， 几十年因此，不可能通过直接观察这些干预措施的全部成本和收益， 有时间限制的审判。根据最近NIH的政策声明，我们将通过应用创新的、经过验证的微观模拟建模方法--一种整合试验结果的系统科学方法--来克服这个问题 提供了关于饮食变化对整个生命过程中CVD风险和成本影响的全面数据。我们将 确定哪些代金券交付策略具有成本效益地降低CVD风险-解决一个关键的科学问题 健康饮食干预研究的不确定性。

Abstract 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. Increasing food assistance funding alone does not resolve this problem, but 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 in- convenience of utilizing targeted funds. Our preliminary data support both hypotheses, which we will rigorously test 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 all major food stores (e.g., supermarkets, corner shops) in two low-income neighborhoods. Leveraging this innovative infrastructure, in Aim 1 we propose 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. In Aim 2, we will calculate the cost-effectiveness of the voucher programs. Vouchers and other interventions that support healthy diets reduce population-level CVD disparities over the course of decades. Hence, the full costs and benefits of such interventions are not possible to directly observe through time-limited trials. Following recent NIH policy statements, we will overcome this problem by applying an innovative, validated microsimulation modeling approach—a systems science method that integrates trial results with comprehensive data on the effect of dietary changes on CVD risks and costs over the life course. We will identify which voucher delivery strategies cost-effectively reduce CVD disparities—addressing a key scientific uncertainty in healthy eating intervention research.