UNASSIGNED: We applied a modified OHAT approach and a broader \"narrative\" assessment to assess the level of confidence in a large systematic review on traffic-related air pollution and health outcomes.
UNASSIGNED: We discuss several challenges with the OHAT approach and its implementation and suggest improvements for synthesizing evidence from observational studies in environmental health. We consider the determination of confidence using a formal rating scheme of up- and downgrading of certain factors, the treatment of every factor as equally important, and the lower initial confidence rating of observational studies to be fundamental issues in the OHAT approach. We argue that some observational studies can offer high-confidence evidence in environmental health. We note that heterogeneity in magnitude of effect estimates should generally not weaken the confidence in the evidence, and consistency of associations across study designs, populations, and exposure assessment methods may strengthen confidence in the evidence. We mention that publication bias should be explored beyond statistical methods and is likely limited when large and collaborative studies comprise most of the evidence and when accrued over several decades. We propose to identify possible key biases, their most likely direction, and their potential impacts on the results. We think that the OHAT approach and other GRADE-type frameworks require substantial modification to align better with features of environmental health questions and the studies that address them. We emphasize that a broader, \"narrative\" evidence assessment based on the systematic review may complement a formal GRADE-type evaluation. https://doi.org/10.1289/EHP11532.
我们采用了改进的OHAT方法和更广泛的“叙事”评估,以评估与交通相关的空气污染和健康结果的大型系统审查的信心水平。
■我们讨论了OHAT方法及其实施的几个挑战,并提出了改进措施,以综合环境健康观察研究的证据。我们考虑使用对某些因素进行上调和下调的正式评级方案来确定置信度,对每个因素的处理同样重要,观察性研究的初始置信度较低是OHAT方法中的基本问题。我们认为,一些观察性研究可以为环境健康提供高可信度的证据。我们注意到,效应估计大小的异质性通常不应削弱对证据的信心,以及研究设计之间关联的一致性,人口,暴露评估方法可以增强对证据的信心。我们提到,应该在统计方法之外探索出版偏见,当大型和合作研究包含大部分证据时,当几十年来积累时,出版偏见可能是有限的。我们建议找出可能的关键偏见,他们最有可能的方向,以及它们对结果的潜在影响。我们认为,OHAT方法和其他等级类型的框架需要进行大量修改,以更好地与环境健康问题的特征以及解决这些问题的研究保持一致。我们强调,基于系统评价的“叙述性”证据评估可以补充正式的等级类型评估。https://doi.org/10.1289/EHP11532.