Pediatrics, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
Health Research Methods, Evidence and Impact, McMaster University, Hamilton, Ontario, Canada.
BMJ Open. 2022 Feb 15;12(2):e056991. doi: 10.1136/bmjopen-2021-056991.
Children from low-income households are at an increased risk of social, behavioural and physical health problems. Prior studies have generally relied on dichotomous outcome measures. However, inequities may exist along the range of outcome distribution. Our objective was to examine differences in distribution of three child health outcomes by income categories (high vs low): body mass index (BMI), behaviour difficulties and development.
This was a cross-sectional study using data from a primary care-based research network with sites in three Canadian cities, and 15 practices enrolling participants.
PARTICIPANTS, INDEPENDENT VARIABLE AND OUTCOMES: The independent variable was annual household income, dichotomised at the median income for Toronto (<$C80 000 or ≥$C80 000). Outcomes were: (1) growth (BMI z-score (zBMI) at 5 years, 1628 participants); (2) behaviour (Strengths and Difficulties Questionnaire (SDQ) at 3-5 years, 649 participants); (3) development (Infant Toddler Checklist (ITC) at 18 months, 1405 participants). We used distributional decomposition to compare distributions of these outcomes for each income group, and then to construct a counterfactual distribution that describes the hypothetical distribution of the low-income group with the predictor profile of the higher-income group.
We included data from 1628 (zBMI), 649 (SDQ) and 1405 (ITC) children. Children with lower family income had a higher risk distribution for all outcomes. For all outcomes, thecounterfactual distribution, which represented the distribution of children with lower-income who were assigned the predictor profile of the higher-income group, was more favourable than their observed distributions.
Comparing the distributions of child health outcomes and understanding different risk profiles for children from higher-income and lower-income groups can offer a deeper understanding of inequities in child health outcomes. These methods may offer an approach that can be implemented in larger datasets to inform future interventions.
来自低收入家庭的儿童面临更高的社会、行为和身体健康问题风险。先前的研究通常依赖于二分结局测量。然而，不平等可能存在于结局分布的整个范围内。我们的目的是检查三种儿童健康结局（高收入与低收入）的分布差异：体重指数（BMI）、行为困难和发育。
这是一项使用来自三个加拿大城市的基于初级保健的研究网络的数据进行的横断面研究，有 15 个实践点招募参与者。
参与者、自变量和结局：自变量是家庭年收入，以多伦多中位数收入（<$C80000 或 ≥$C80000）进行二分。结局为：（1）生长（5 岁时 BMI 标准差分数（zBMI），1628 名参与者）；（2）行为（3-5 岁时长处与困难问卷（SDQ），649 名参与者）；（3）发育（18 个月时婴儿-幼儿检查表（ITC），1405 名参与者）。我们使用分布分解来比较每个收入组的这些结局的分布，然后构建一个反事实分布，该分布描述了低收人群体在高收人群体预测特征下的假设分布。
我们纳入了来自 1628 名（zBMI）、649 名（SDQ）和 1405 名（ITC）儿童的数据。家庭收入较低的儿童所有结局的风险分布更高。对于所有结局，反事实分布，代表了收入较低的儿童被分配给较高收入组的预测特征的分布，比他们的实际分布更有利。
比较儿童健康结局的分布，并了解高收入和低收入组儿童的不同风险特征，可以更深入地了解儿童健康结局的不平等。这些方法可能提供一种可以在更大数据集上实施的方法，以告知未来的干预措施。
