Natural experiment on contextual effects on health and health care among refugees (NEXUS)

许多关于环境健康影响的研究受到成分偏见和选择性迁移到社区的影响。纵向自然实验有可能克服这些限制，但这些是罕见的现象，在公共卫生中没有得到充分利用。移民分散政策有资格作为一个自然实验，因为对社区的分配是由行政原因以准随机的方式发生的。PH-LENS研究单位的这个子项目旨在通过利用分散政策作为自然实验，研究边缘化移民人口的健康不平等与居住地环境特征（如住宿、邻里和区域剥夺）之间的关系。进一步的目标是评估卫生系统如何利用复原力和响应性框架促进、缓解或减少边缘化人群在卫生和卫生保健方面的不平等。NEXUS包括四个工作包（WP）：系统审查移民分散计划研究对健康和社会结果的背景影响（WP1）；对来自60个住宿中心和6个接待中心的560名难民进行纵向自然实验的具有独立横截面的伪面板调查数据的二次分析（WP2）；一项前瞻性自然实验研究，对1,200名寻求庇护者和300名孕妇进行初步数据收集和测量，这些孕妇将在国家接待中心招募，并在分散到44个地区后进行12个月的随访（WP3）；并通过meta分析方法对伪小组和前瞻性研究的结果进行比较，以提高上下文健康研究的方法学知识（WP4）。此外，作为第三次世界卫生行动计划的一部分，将对区域卫生系统的主要利益攸关方进行定性访谈，以制定区域卫生系统行为者的定量调查，旨在衡量所有44个县的复原力。应用的分析方法包括倾向得分匹配，差异分析中的差异，以及贝叶斯和多层次回归。NEXUS应用创新的研究设计来解决这些目标，并通过产生关于“其他”过程的机制和后果以及它们与环境的相互作用的经验知识来为研究单位做出贡献，这些知识可以转移到社会中其他边缘化的社会群体。该分项目还将产生关于区域卫生系统因素在减少或增加卫生不平等方面作用的知识，并加强关于自然实验和复原力测量的方法学知识。NEXUS与子项目ENSURE和TREAT一起采用协同方法收集数据，并与子项目OTHER、DEPRIV、PROREF和LARGE密切合作，为PH-LENS研究单位的总体目标做出贡献。

Many studies on contextual health effects suffer from compositional bias and selective migration into neighbourhoods. Longitudinal natural experiments have the potential to overcome these limitations, but these are rare phenomena and underused in public health. Migrant dispersal policies qualify as a natural experiment as the assignment to neighbourhoods occurs by administrative reasons in quasi-random fashion. This sub-project of the research unit PH-LENS aims to study the relationships between health inequalities and contextual characteristics of the place of residence, such as accommodation, neighbourhood, and regional deprivation, in a marginalised migrant population by exploiting dispersal policies as a natural experiment. Further aims are to assess how health systems contribute to, mitigate, or reduce inequalities in health and health care of marginalised populations using resilience and responsiveness frameworks. NEXUS comprises four work packages (WP): A systematic review on contextual effects on health and social outcomes derived from studies on migrant dispersal programs (WP1); a secondary analysis of survey data from a pseudo-panel with independent cross-sections used to approximate a longitudinal natural experiment among 560 refugees from 60 accommodation centres and six reception centres (WP2); a prospective natural experiment study with primary data collection and measurement of both contextual and individual factors among 1,200 asylum seekers and 300 pregnant women who will be recruited in a state reception centre and followed-up for 12 months after dispersal between 44 districts (WP3); and a comparison between results of the pseudo-panel and the prospective study by meta-analytic approaches to advance methodological knowledge on contextual health research (WP4). Additionally, as part of WP3, qualitative interviews with key stakeholders in regional health systems will be performed to develop a quantitative survey of regional health system actors, aimed at measuring resilience in all 44 districts. The analytical approaches applied comprise propensity score matching, difference in difference analysis, as well as Bayesian and multi-level regression. NEXUS applies innovative research designs to address these objectives, and contributes to the research unit by generating empirical knowledge on mechanisms and consequences of ‘othering’ processes and their interaction with context, which may be transferable to other marginalised social groups in society. The sub-project will also generate knowledge on the role of regional health system factors in reducing or increasing health inequalities and enhance methodological knowledge on natural experiments and measurements of resilience. NEXUS uses a synergistic approach to data collection jointly with the sub-projects ENSURE and TREAT, and closely collaborates with the sub-projects OTHER, DEPRIV, PROREF and LARGE to contribute to the overall goals of the Research Unit PH-LENS.