Waterlander Wilma E, Blakely Tony, Nghiem Nhung, Cleghorn Christine L, Eyles Helen, Genc Murat, Wilson Nick, Jiang Yannan, Swinburn Boyd, Jacobi Liana, Michie Jo, Ni Mhurchu Cliona
National Institute for Health Innovation, School of Population Health, University of Auckland, Auckland, New Zealand.
Department of Public Health, University of Otago, Wellington, New Zealand.
BMC Public Health. 2016 Jul 19;16:601. doi: 10.1186/s12889-016-3277-5.
There is a need for accurate and precise food price elasticities (PE, change in consumer demand in response to change in price) to better inform policy on health-related food taxes and subsidies.
METHODS/DESIGN: The Price Experiment and Modelling (Price ExaM) study aims to: I) derive accurate and precise food PE values; II) quantify the impact of price changes on quantity and quality of discrete food group purchases and; III) model the potential health and disease impacts of a range of food taxes and subsidies. To achieve this, we will use a novel method that includes a randomised Virtual Supermarket experiment and econometric methods. Findings will be applied in simulation models to estimate population health impact (quality-adjusted life-years [QALYs]) using a multi-state life-table model. The study will consist of four sequential steps: 1. We generate 5000 price sets with random price variation for all 1412 Virtual Supermarket food and beverage products. Then we add systematic price variation for foods to simulate five taxes and subsidies: a fruit and vegetable subsidy and taxes on sugar, saturated fat, salt, and sugar-sweetened beverages. 2. Using an experimental design, 1000 adult New Zealand shoppers complete five household grocery shops in the Virtual Supermarket where they are randomly assigned to one of the 5000 price sets each time. 3. Output data (i.e., multiple observations of price configurations and purchased amounts) are used as inputs to econometric models (using Bayesian methods) to estimate accurate PE values. 4. A disease simulation model will be run with the new PE values as inputs to estimate QALYs gained and health costs saved for the five policy interventions.
The Price ExaM study has the potential to enhance public health and economic disciplines by introducing internationally novel scientific methods to estimate accurate and precise food PE values. These values will be used to model the potential health and disease impacts of various food pricing policy options. Findings will inform policy on health-related food taxes and subsidies.
Australian New Zealand Clinical Trials Registry ACTRN12616000122459 (registered 3 February 2016).
需要准确且精确的食品价格弹性（PE，即消费者需求随价格变化的改变），以便为与健康相关的食品税和补贴政策提供更充分的信息。
方法/设计：价格实验与建模（Price ExaM）研究旨在：I）得出准确且精确的食品PE值；II）量化价格变化对各类食品购买量和质量的影响；III）模拟一系列食品税和补贴对健康和疾病的潜在影响。为实现这一目标，我们将采用一种新颖的方法，该方法包括随机虚拟超市实验和计量经济学方法。研究结果将应用于模拟模型，使用多状态生命表模型估计人群健康影响（质量调整生命年[QALYs]）。该研究将包括四个连续步骤：1. 我们为虚拟超市中的1412种食品和饮料产品生成5000个具有随机价格变化的价格集。然后，我们为食品添加系统性价格变化，以模拟五种税和补贴：果蔬补贴以及对糖、饱和脂肪、盐和含糖饮料的税。2. 使用实验设计，1000名成年新西兰购物者在虚拟超市完成五次家庭食品杂货店购物，每次他们被随机分配到5000个价格集中的一个。3. 输出数据（即价格配置和购买量的多次观测值）用作计量经济学模型（使用贝叶斯方法）的输入，以估计准确的PE值。4. 将运行一个疾病模拟模型，以新的PE值作为输入，估计五项政策干预措施所获得的QALYs和节省的健康成本。
Price ExaM研究有潜力通过引入国际上新的科学方法来估计准确且精确的食品PE值，从而加强公共卫生和经济学科。这些值将用于模拟各种食品定价政策选项对健康和疾病的潜在影响。研究结果将为与健康相关的食品税和补贴政策提供信息。
澳大利亚新西兰临床试验注册中心ACTRN12616000122459（2016年2月3日注册）。
