Biddle Louise, Hintermeier Maren, Costa Diogo, Wasko Zahia, Bozorgmehr Kayvan
Department of Population Medicine and Health Services Research, School of Public Health, Bielefeld University, Universitätsstraße 25, 33501, Bielefeld, Germany.
German Socio-Economic Panel, German Institute for Economic Research (DIW Berlin), Mohrenstraße 58, 10117, Berlin, Germany.
EClinicalMedicine. 2023 Sep 18;64:102206. doi: 10.1016/j.eclinm.2023.102206. eCollection 2023 Oct.
Migration health research pays little attention to the places into which people migrate. Studies on health effects of contextual factors are often limited because of the ability of individuals to self-select their environment, but natural experiments may allow for the causal effect of contexts to be examined. The objective was to synthesise the evidence on contextual health effects from natural experiments among migrant groups.
We performed a systematic review of natural experiments among migrant populations in PubMed/MEDLINE, The Cochrane Library, Web of Science, CINAHL and Google Scholar for literature published until 13 October 2022. 5870 articles were screened in duplicate using the following inclusion criteria: quantitative natural experiment design, migrant population, context factor as treatment variable and health or healthcare outcome variable. Synthesis without meta-analysis was performed following quality appraisal using the EPHPP tool for quantitative studies and data extraction (PROSPERO: CRD42020169236).
The 46 included articles provide evidence for negative effects of neighbourhood disadvantage on physical health and mortality, while finding mixed effects on mental health. Articles comparing migrants with those that stayed behind demonstrate detrimental effects of migration and adverse post-migratory contexts on physical health and mortality, while demonstrating favourable effects for mental and child health. Natural experiments of policy environments indicate the negative impacts of restrictive migration and social policies on healthcare utilization, mental health and mortality, as well as the positive health effects when restrictions are lifted.
Natural experiments complement observational studies and provide robust evidence to advocate for more inclusive migration, health and social policies as well as neighbourhood improvement programmes. In order to strengthen the methodological approach, future research utilising natural experiments should be more explicit in the mechanisms underlying the experiment and provide details on potential causal mechanisms for the observed effects.
German Science Foundation (FOR: 2928/GZ: BO5233/1-1).
移民健康研究很少关注人们移民前往的地方。由于个体能够自我选择其环境，关于背景因素对健康影响的研究往往受到限制，但自然实验可能有助于检验背景因素的因果效应。目的是综合移民群体中自然实验关于背景因素对健康影响的证据。
我们对PubMed/MEDLINE、Cochrane图书馆、科学网、护理学与健康领域数据库（CINAHL）和谷歌学术中截至2022年10月13日发表的有关移民人群自然实验的文献进行了系统综述。使用以下纳入标准对5870篇文章进行了重复筛选：定量自然实验设计、移民人群、作为处理变量的背景因素以及健康或医疗结果变量。在使用EPHPP工具对定量研究进行质量评估和数据提取后（国际前瞻性系统评价注册库：CRD42020169236），进行了无荟萃分析的综合。
纳入的46篇文章提供了证据，表明邻里劣势对身体健康和死亡率有负面影响，而对心理健康的影响则喜忧参半。将移民与留在原籍地的人进行比较的文章表明，移民以及移民后的不利背景对身体健康和死亡率有不利影响，而对心理健康和儿童健康有有利影响。政策环境的自然实验表明，限制性移民政策和社会政策对医疗保健利用、心理健康和死亡率有负面影响，而取消限制则对健康有积极影响。
自然实验补充了观察性研究，并提供了有力证据，以倡导更具包容性的移民、健康和社会政策以及邻里改善计划。为了加强方法学方法，未来利用自然实验的研究应更明确实验背后的机制，并提供观察到的效应的潜在因果机制的详细信息。
德国科学基金会（资助编号：FOR: 2928/GZ: BO5233/1-1）
