Mel and Enid Zuckerman College of Public Health, University of Arizona, Tucson, AZ, United States.
Front Public Health. 2022 Jul 5;10:863402. doi: 10.3389/fpubh.2022.863402. eCollection 2022.
Poorly soluble low toxicity particles such as carbon black and titanium dioxide have raised concern about possible nonmalignant and malignant pulmonary effects. This paper illustrates application of causal inference analysis to assessing these effects. A framework for analysis is created using directed acyclic graphs to define pathways from exposure to potential lung cancer or chronic airflow obstruction outcomes. Directed acyclic graphs define influences of confounders, backdoor pathways, and analytic models. Potential mechanistic pathways such as intermediate pulmonary inflammation are illustrated. An overview of available data for each of the inter-node links is presented. Individual empirical epidemiologic studies have limited ability to confirm mechanisms of potential causal relationships due to the complexity of causal pathways and the extended time course over which disease may develop. Therefore, an explicit conceptual and graphical framework to facilitate synthesizing data from several studies to consider pulmonary inflammation as a common pathway for both chronic airflow obstruction and lung cancer is suggested. These methods are useful to clarify potential bona fide and artifactual observed relationships. They also delineate variables which should be included in analytic models for single study data and biologically relevant variables unlikely to be available from a single study.
像炭黑和二氧化钛这样的难溶性低毒性颗粒引起了人们对可能的非恶性和恶性肺部影响的关注。本文说明了应用因果推理分析来评估这些影响的方法。使用有向无环图创建了一个分析框架，以定义从暴露到潜在肺癌或慢性气流阻塞结果的途径。有向无环图定义了混杂因素、后门途径和分析模型的影响。中间性肺部炎症等潜在的机制途径也进行了说明。还介绍了每个节点间链接的可用数据概述。由于因果途径的复杂性以及疾病可能发展的时间延长，单个经验性流行病学研究由于确认潜在因果关系机制的能力有限。因此，建议采用明确的概念和图形框架，将来自几项研究的数据综合起来，将肺部炎症作为慢性气流阻塞和肺癌的共同途径进行考虑。这些方法有助于澄清潜在的真实和人为观察到的关系。它们还描绘了分析模型中应包括的变量以及单个研究中可能无法获得的生物学相关变量。
