Department of Environment, Climate Change and Health, World Health Organization, Avenue Appia 20, 1202, Geneva, Switzerland.
General Internal Medicine/Public Health/Center for Bioethics and Humanities, University of Colorado-Anschutz Medical Campus, Denver, CO, USA.
Environ Health. 2022 Jul 6;21(1):64. doi: 10.1186/s12940-022-00878-4.
Exposure prevalence studies (as here defined) record the prevalence of exposure to environmental and occupational risk factors to human health. Applying systematic review methods to the synthesis of these studies would improve the rigour and transparency of normative products produced based on this evidence (e.g., exposure prevalence estimates). However, a dedicated framework, including standard methods and tools, for systematically reviewing exposure prevalence studies has yet to be created. We describe the need for this framework and progress made towards it through a series of such systematic reviews that the World Health Organization and the International Labour Organization conducted for their WHO/ILO Joint Estimates of the Work-related Burden of Disease and Injury (WHO/ILO Joint Estimates).We explain that existing systematic review frameworks for environmental and occupational health cannot be directly applied for the generation of exposure prevalence estimates because they seek to synthesise different types of evidence (e.g., intervention or exposure effects on health) for different purposes (e.g., identify intervention effectiveness or exposure toxicity or carcinogenicity). Concepts unique to exposure prevalence studies (e.g., "expected heterogeneity": the real, non-spurious variability in exposure prevalence due to exposure changes over space and/or time) also require new assessment methods. A framework for systematic reviews of prevalence of environmental and occupational exposures requires adaptation of existing methods (e.g., a standard protocol) and development of new tools or approaches (e.g., for assessing risk of bias and certainty of a body of evidence, including exploration of expected heterogeneity).As part of the series of systematic reviews for the WHO/ILO Joint Estimates, the World Health Organization collaborating with partners has created a preliminary framework for systematic reviews of prevalence studies of exposures to occupational risk factors. This included development of protocol templates, data extraction templates, a risk of bias assessment tool, and an approach for assessing certainty of evidence in these studies. Further attention and efforts are warranted from scientific and policy communities, especially exposure scientists and policy makers, to establish a standard framework for comprehensive and transparent systematic reviews of studies estimating prevalence of exposure to environmental and occupational risk factors, to improve estimates, risk assessments and guidelines.
暴露流行率研究（如本文所定义）记录了环境和职业危险因素对人类健康的流行率。将系统评价方法应用于这些研究的综合分析，可以提高基于这些证据（例如，暴露流行率估计值）制定的规范产品的严谨性和透明度。然而，一个专门的框架，包括标准方法和工具，用于系统地审查暴露流行率研究，尚未建立。我们通过世界卫生组织（世卫组织）和国际劳工组织（劳工组织）为其世卫组织/劳工组织联合疾病和伤害工作相关负担估计数（世卫组织/劳工组织联合估计数）进行的一系列此类系统审查，描述了对这种框架的需求以及在这方面取得的进展。我们解释说，现有的环境和职业健康系统评价框架不能直接用于生成暴露流行率估计值，因为它们旨在综合不同类型的证据（例如，对健康的干预或暴露影响）用于不同的目的（例如，确定干预效果或暴露毒性或致癌性）。暴露流行率研究特有的概念（例如，“预期异质性”：由于暴露在空间和/或时间上的变化而导致暴露流行率的真实而非虚假变异性）也需要新的评估方法。一个用于系统评价环境和职业暴露流行率的框架需要适应现有方法（例如，标准方案）和开发新的工具或方法（例如，用于评估偏倚风险和证据体的确定性，包括探索预期异质性）。作为世卫组织/劳工组织联合估计数系列系统评价的一部分，世界卫生组织与合作伙伴合作，为职业危险因素暴露流行率研究的系统评价创建了一个初步框架。这包括制定方案模板、数据提取模板、偏倚风险评估工具以及这些研究中证据确定性评估方法。科学和政策界，特别是暴露科学家和决策者，需要进一步关注和努力，为估计环境和职业危险因素暴露流行率的研究建立一个全面透明的系统评价标准框架，以提高估计值、风险评估和准则。
