Smith-Drelich Noah
Stanford Law School,JD,Stanford University,MS - E-IPER (Health Policy),2860 US Highway 51 North,Anna,IL 62906,USA.
Public Health Nutr. 2016 Feb;19(3):520-9. doi: 10.1017/S1368980015001469. Epub 2015 Jun 9.
To measure the impact of a reimbursement-based consumer subsidy on vegetable expenditures, consumption and waste.
Two-arm randomized controlled trial; two-week baseline observation period, three-week intervention period. Participants' vegetable expenditures, consumption and waste were monitored using receipts collection and through an FFQ. During the intervention period, the treatment group received reimbursement of up to 50 US dollars ($) for purchased vegetables.
Participants were solicited from Palo Alto, CA, USA using materials advertising a 'consumer behavior study' and a small participation incentive. To prevent selection bias, solicitation materials did not describe the specific behaviour being evaluated.
One hundred and fifty potential participants responded to the solicitations and 144 participants enrolled in the study; 138 participants completed all five weekly surveys.
Accounting for the control group (n 69) and the two-week baseline period, the intervention significantly impacted the treatment group's (n 69) vegetable expenditures (+$8.16 (sd 2.67)/week, P<0.01), but not vegetable consumption (+1.3 (sd 1.2) servings/week, P=0.28) or waste (-0.23 (sd 1.2) servings/week, P=0.60).
The consumer subsidy significantly increased participants' vegetable expenditures, but not consumption or waste, suggesting that this type of subsidy might not have the effects anticipated. Reimbursement-based consumer subsidies may therefore not be as useful a policy tool for impacting vegetable consumption as earlier studies have suggested. Moreover, moderation analysis revealed that the subsidy's effect on participants' vegetable expenditures was significant only in men. Additional research should seek to determine how far reaching gender-specific effects are in this context. Further research should also examine the effect of a similar consumer subsidy on high-risk populations and explore to what extent increases in participants' expenditures are due to the purchase of more expensive vegetables, purchasing of vegetables during the study period that were consumed outside the study period, or a shift from restaurant vegetable consumption to grocery vegetable consumption.
衡量基于报销的消费者补贴对蔬菜支出、消费和浪费的影响。
双臂随机对照试验；为期两周的基线观察期，为期三周的干预期。通过收据收集和食物频率问卷对参与者的蔬菜支出、消费和浪费情况进行监测。在干预期，治疗组购买蔬菜可获得最高50美元的报销。
使用宣传“消费者行为研究”的材料和少量参与激励措施，从美国加利福尼亚州帕洛阿尔托招募参与者。为防止选择偏差，宣传材料未描述所评估的具体行为。
150名潜在参与者回应了招募，144名参与者纳入研究；138名参与者完成了所有五周的调查。
将对照组（n = 69）和两周基线期考虑在内，干预对治疗组（n = 69）的蔬菜支出产生了显著影响（每周增加8.16美元（标准差2.67），P<0.01），但对蔬菜消费（每周增加1.3份（标准差1.2），P = 0.28）或浪费（每周减少0.23份（标准差1.2），P = 0.60）没有显著影响。
消费者补贴显著增加了参与者的蔬菜支出，但未增加消费或减少浪费，表明此类补贴可能未产生预期效果。因此，基于报销的消费者补贴可能不像早期研究所表明的那样，是影响蔬菜消费的有效政策工具。此外，调节分析显示，补贴对参与者蔬菜支出的影响仅在男性中显著。后续研究应确定在此背景下特定性别的影响范围有多广。进一步的研究还应考察类似消费者补贴对高危人群的影响，并探究参与者支出增加在多大程度上是由于购买了更昂贵的蔬菜、在研究期间购买但在研究期外消费的蔬菜，还是从餐厅蔬菜消费转向杂货店蔬菜消费。
