Confounding mechanisms and adjustment strategies in air pollution epidemiology: a case study assessment with the UK Biobank cohort.

IF 5.9 2区 医学 Q1 PUBLIC, ENVIRONMENTAL & OCCUPATIONAL HEALTH
Jacopo Vanoli, Lina Madaniyazi, Massimo Stafoggia, Chris Fook Sheng Ng, Antonio Gasparrini
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引用次数: 0

Abstract

Background: Cohort studies are instrumental in examining long-term risks associated with environmental exposures but require appropriate control for various confounding effects. In this contribution, we assessed this issue by investigating the relationship between fine particulate matter (PM2.5) exposure and mortality in a UK-based cohort.

Methods: We analysed data from half a million adults in the UK Biobank linked with time-varying individual-level exposure data and followed up during the period 2006-21. The assessment focused on confounding related to spatial and temporal patterns as well as due to measurable variables, including both contextual and individual-level factors. We performed an evaluation consisting of descriptive analyses, specification and interpretation of direct acyclic graphs (DAGs), and comparison of results from survival models.

Results: We found correlations between PM2.5 exposure and mortality rates across time, geographical areas, and categories of measurable variables. The DAG indicated complex causal pathways and the need to adjust for a wide set of potential confounders. The regression analysis confirmed these patterns: the fully adjusted model estimated a hazard ratio (HR) of 1.25 (95% CI: 1.06-1.49) per 10 μg/m3 increments in PM2.5, but the association reversed to 0.82 (0.76-0.87) when excluding control for recruitment centre, suggesting strong spatial confounding. Calendar time showed stronger confounding effects compared to age. Area-level socio-economic indicators were more important than individual-level counterparts, while lack of control for lifestyle factors led to a noticeable overestimation.

Conclusions: This case-study illustration elucidates various confounding mechanisms in cohort studies on environmental risks and offers a critical evaluation of alternative adjustment strategies.

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空气污染流行病学中的混淆机制和调整策略:英国生物银行队列的案例研究评估。
背景:队列研究有助于检查与环境暴露相关的长期风险,但需要适当控制各种混杂效应。在这篇文章中,我们通过调查细颗粒物(PM2.5)暴露与英国队列死亡率之间的关系来评估这一问题。方法:我们分析了英国生物银行中50万成年人的数据,这些数据与随时间变化的个人暴露数据有关,并在2006-21年期间进行了随访。评估的重点是与空间和时间格局有关的混淆以及可测量变量,包括环境因素和个人因素。我们进行了一项评估,包括描述性分析,直接无环图(dag)的说明和解释,以及生存模型结果的比较。结果:我们发现PM2.5暴露与死亡率在不同时间、地理区域和可测量变量类别之间存在相关性。DAG显示了复杂的因果途径,需要对广泛的潜在混杂因素进行调整。回归分析证实了这些模式:完全调整模型估计PM2.5每增加10 μg/m3,风险比(HR)为1.25 (95% CI: 1.06-1.49),但当排除招募中心的控制时,相关系数逆转为0.82(0.76-0.87),表明空间混淆很强。与年龄相比,日历时间显示出更强的混淆效应。地区一级的社会经济指标比个人一级的指标更重要,而由于缺乏对生活方式因素的控制,导致明显的高估。结论:本案例研究阐明了环境风险队列研究中的各种混淆机制,并提供了替代调整策略的关键评估。
本文章由计算机程序翻译,如有差异,请以英文原文为准。
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来源期刊
International journal of epidemiology
International journal of epidemiology 医学-公共卫生、环境卫生与职业卫生
CiteScore
13.60
自引率
2.60%
发文量
226
审稿时长
3 months
期刊介绍: The International Journal of Epidemiology is a vital resource for individuals seeking to stay updated on the latest advancements and emerging trends in the field of epidemiology worldwide. The journal fosters communication among researchers, educators, and practitioners involved in the study, teaching, and application of epidemiology pertaining to both communicable and non-communicable diseases. It also includes research on health services and medical care. Furthermore, the journal presents new methodologies in epidemiology and statistics, catering to professionals working in social and preventive medicine. Published six times a year, the International Journal of Epidemiology provides a comprehensive platform for the analysis of data. Overall, this journal is an indispensable tool for staying informed and connected within the dynamic realm of epidemiology.
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