Department of Population Health, New York University Grossman School of Medicine, New York, New York.
Perelman School of Medicine, University of Pennsylvania, Philadelphia.
JAMA Netw Open. 2023 Mar 1;6(3):e232371. doi: 10.1001/jamanetworkopen.2023.2371.
Despite recent growth in online redemption of Supplemental Nutrition Assistance Program (SNAP) benefits, no previous work has tested the impact of economic and behavioral economic strategies on food purchasing behaviors in an online grocery retail setting among adults with low income.
To examine the extent to which financial incentives and default shopping cart options influence fruit and vegetable purchases.
DESIGN, SETTING, AND PARTICIPANTS: This randomized clinical trial used an experimental online grocery store for adults who currently or have ever received SNAP benefits. From October 7 to December 2, 2021, participants were instructed to shop for a week's worth of groceries for their household, with a budget tailored to household size; no payment was taken.
Random assignment to 1 of 4 conditions: no intervention, 50% discount on eligible fruits and vegetables, prefilled shopping carts with tailored fruit and vegetable items (ie, default options), or a combination of the discount and default options.
The primary outcome was the percentage of nondiscounted dollars spent on eligible fruit and vegetables per basket.
Of 2744 participants, mean (SD) age was 46.7 (16.0) years, and 1447 (52.7%) identified as women. A total of 1842 participants (67.1%) reported currently receiving SNAP benefits and 1492 (54.4%) reported shopping online for groceries in the previous 12 months. Participants spent a mean (SD) 20.5% (23.5%) of total dollars on eligible fruits and vegetables. Compared with no intervention, those in the discount condition spent 4.7% (98.3% CI, 1.7%-7.7%) of more total dollars on eligible fruits and vegetables; those in the default condition, 7.8% (98.3% CI, 4.8%-10.7%) more; and those in the combination condition, 13.0% (98.3% CI, 10.0%-16.0%) more (P < .001 for all). There was no difference between the discount and the default conditions (P = .06), but the effect in the combination condition was significantly larger than both discount and default conditions (P < .001). Default shopping cart items were purchased by 679 participants (93.4%) in the default condition and 655 (95.5%) in the combination condition, whereas 297 (45.8%) in the control and 361 (52.9%) in the discount conditions purchased those items (P < .001). No variation was observed by age, sex, or race and ethnicity, and results were similar when those who reported never shopping online for groceries were excluded.
In this randomized clinical trial, financial incentives for fruits and vegetables and default options, especially in combination, led to meaningful increases in online fruit and vegetable purchases among adults with low income.
ClinicalTrials.gov Identifier: NCT04766034.
重要性：尽管补充营养援助计划 (SNAP) 福利的在线兑现最近有所增长，但以前没有任何研究测试经济和行为经济学策略对低收入成年人在在线杂货零售环境中购买食品行为的影响。
目的：研究经济激励和默认购物车选项在多大程度上影响水果和蔬菜的购买。
设计、设置和参与者：这是一项使用专为成年人设计的实验性在线杂货店的随机临床试验，这些成年人目前或曾经领取过 SNAP 福利。从 2021 年 10 月 7 日至 12 月 2 日，参与者被指示为家庭购买一周的杂货，预算根据家庭规模定制；不收取任何费用。
干预措施：随机分配到 4 个条件之一：无干预、合格水果和蔬菜 50%折扣、填充有定制水果和蔬菜项目的购物车（即默认选项），或折扣和默认选项的组合。
主要结果和测量：主要结果是每个篮子中非折扣美元在合格水果和蔬菜上的支出百分比。
结果：在 2744 名参与者中，平均（SD）年龄为 46.7（16.0）岁，1447 名（52.7%）为女性。共有 1842 名参与者（67.1%）报告目前正在领取 SNAP 福利，1492 名（54.4%）报告在过去 12 个月中在线购买过杂货。参与者平均（SD）花费总支出的 20.5%（98.3%CI，1.7%-7.7%）用于合格的水果和蔬菜。与无干预相比，折扣条件下的参与者在合格水果和蔬菜上的支出增加了 4.7%（98.3%CI，1.7%-7.7%）；默认条件下增加了 7.8%（98.3%CI，4.8%-10.7%）；组合条件下增加了 13.0%（98.3%CI，10.0%-16.0%）（所有 P 值均<.001）。折扣和默认条件之间没有差异（P=.06），但组合条件的效果明显大于折扣和默认条件（P<.001）。在默认条件下，有 679 名参与者（93.4%）购买了默认购物车项目，在组合条件下有 655 名（95.5%）购买了这些项目，而在对照组中有 297 名（45.8%）和在折扣条件下有 361 名（52.9%）购买了这些项目（P<.001）。在年龄、性别或种族和民族方面没有观察到差异，当排除从未在网上购买过杂货的人时，结果相似。
结论和相关性：在这项随机临床试验中，水果和蔬菜的经济激励和默认选项，尤其是两者的结合，显著增加了低收入成年人在网上购买水果和蔬菜的数量。
试验注册：ClinicalTrials.gov 标识符：NCT04766034。
