Department of Health Systems and Population Health, University of Washington, Seattle.
Department of Epidemiology, University of Washington, Seattle.
JAMA Netw Open. 2024 May 1;7(5):e2413644. doi: 10.1001/jamanetworkopen.2024.13644.
Sweetened beverage taxes have been associated with reduced purchasing of taxed beverages. However, few studies have assessed the association between sweetened beverage taxes and health outcomes.
To evaluate the association between the Seattle sweetened beverage tax and change in body mass index (BMI) among children.
DESIGN, SETTING, AND PARTICIPANTS: In this longitudinal cohort study, anthropometric data were obtained from electronic medical records of 2 health care systems (Kaiser Permanente Washington [KP] and Seattle Children's Hospital Odessa Brown Children's Clinic [OBCC]). Children were included in the study if they were aged 2 to 18 years (between January 1, 2014, and December 31, 2019); had at least 1 weight measurement every year between 2015 and 2019; lived in Seattle or in urban areas of 3 surrounding counties (King, Pierce, and Snohomish); had not moved between taxed (Seattle) and nontaxed areas; received primary health care from KP or OBCC; did not have a recent history of cancer, bariatric surgery, or pregnancy; and had biologically plausible height and BMI (calculated as weight in kilograms divided by height in meters squared). Data analysis was conducted between August 5, 2022, and March 4, 2024.
Seattle sweetened beverage tax (1.75 cents per ounce on sweetened beverages), implemented on January 1, 2018.
The primary outcome was BMIp95 (BMI expressed as a percentage of the 95th percentile; a newly recommended metric for assessing BMI change) of the reference population for age and sex, using the Centers for Disease Control and Prevention growth charts. In the primary (synthetic difference-in-differences [SDID]) model used, a comparison sample was created by reweighting the comparison sample to optimize on matching to pretax trends in outcome among 6313 children in Seattle. Secondary models were within-person change models using 1 pretax measurement and 1 posttax measurement in 22 779 children and fine stratification weights to balance baseline individual and neighborhood-level confounders.
The primary SDID analysis included 6313 children (3041 female [48%] and 3272 male [52%]). More than a third of children (2383 [38%]) were aged 2 to 5 years); their mean (SE) age was 7.7 (0.6) years. With regard to race and ethnicity, 789 children (13%) were Asian, 631 (10%) were Black, 649 (10%) were Hispanic, and 3158 (50%) were White. The primary model results suggested that the Seattle tax was associated with a larger decrease in BMIp95 for children living in Seattle compared with those living in the comparison area (SDID: -0.90 percentage points [95% CI, -1.20 to -0.60]; P < .001). Results from secondary models were similar.
The findings of this cohort study suggest that the Seattle sweetened beverage tax was associated with a modest decrease in BMIp95 among children living in Seattle compared with children living in nearby nontaxed areas who were receiving care within the same health care systems. Taken together with existing studies in the US, these results suggest that sweetened beverage taxes may be an effective policy for improving children's BMI. Future research should test this association using longitudinal data in other US cities with sweetened beverage taxes.
重要性：含糖饮料税与购买征税饮料的减少有关。然而，很少有研究评估含糖饮料税与健康结果之间的关联。
目的：评估西雅图含糖饮料税与儿童体重指数 (BMI) 变化之间的关系。
设计、地点和参与者：在这项纵向队列研究中，从两个医疗保健系统（Kaiser Permanente Washington [KP] 和西雅图儿童医院 Odessa Brown 儿童诊所 [OBCC]）的电子病历中获取人体测量数据。如果儿童符合以下条件，则将其纳入研究：年龄在 2 至 18 岁之间（2014 年 1 月 1 日至 2019 年 12 月 31 日）；在 2015 年至 2019 年期间，每年至少有 1 次体重测量值；居住在西雅图或周边 3 个县（金、皮尔斯和斯诺霍米什）的城市地区；没有在征税（西雅图）和非征税地区之间迁移；从 KP 或 OBCC 接受初级医疗保健；近期没有癌症、减肥手术或怀孕史；并且具有合理的身高和 BMI（通过体重（公斤）除以身高（米）的平方计算）。数据分析于 2022 年 8 月 5 日至 2024 年 3 月 4 日进行。
暴露：西雅图含糖饮料税（对含糖饮料每盎司征收 1.75 美分）于 2018 年 1 月 1 日实施。
主要结果和测量：主要结果是使用疾病控制与预防中心的生长图表，根据年龄和性别参考人群的 BMIp95（BMI 表示为第 95 个百分位数的百分比；这是一种新推荐的评估 BMI 变化的指标）。在使用的主要（合成差异-差异 [SDID]）模型中，通过重新加权比较样本，优化了在西雅图的 6313 名儿童中，税收前趋势与结果之间的匹配，从而创建了一个比较样本。次要模型是在 22779 名儿童中使用 1 个税收前测量值和 1 个税收后测量值的个体内变化模型，以及使用精细分层权重来平衡基线个体和社区水平的混杂因素。
结果：主要的 SDID 分析包括 6313 名儿童（3041 名女性[48%]和 3272 名男性[52%]）。超过三分之一的儿童（2383 名[38%]）年龄在 2 至 5 岁之间；他们的平均（SE）年龄为 7.7（0.6）岁。在种族和族裔方面，789 名儿童（13%）为亚洲人，631 名（10%）为黑人，649 名（10%）为西班牙裔，3158 名（50%）为白人。主要模型结果表明，与居住在比较地区的儿童相比，西雅图的税收与居住在西雅图的儿童的 BMIp95 下降幅度更大（SDID：-0.90 个百分点[95%CI，-1.20 至 -0.60]；P <.001）。次级模型的结果也相似。
结论和相关性：这项队列研究的结果表明，与居住在附近非征税地区且在同一医疗保健系统内接受护理的儿童相比，西雅图的含糖饮料税与西雅图儿童的 BMIp95 适度下降有关。结合美国现有的研究结果，这些结果表明，含糖饮料税可能是改善儿童 BMI 的有效政策。未来的研究应使用其他有含糖饮料税的美国城市的纵向数据来测试这种关联。
