Department of Social and Behavioral Sciences, Harvard T.H. Chan School of Public Health, Boston, MA, USA.
Department of Public Health Sciences, University of Chicago, IL, USA.
Health Place. 2024 Nov;90:103363. doi: 10.1016/j.healthplace.2024.103363. Epub 2024 Oct 2.
We sought to test the hypothesis that communities with a high degree of income inequality are ill-equipped to deal with crises. Specifically, we tested whether pre-disaster higher income inequality increases the risk of worse mental health conditions in the aftermath of disaster.
We examined the association between pre-disaster community income inequality and post-disaster mental health outcomes in a prospective cohort study of older adults (≥65 years) who survived the 2011 Great East Japan Earthquake. The baseline survey of participants (completed in 2010) predated the disaster by seven months. Survivors completed three waves of post-disaster surveys in 2013, 2016, and 2019. To assess the level of income inequality, the Gini index was calculated using individual income data in 2010 aggregated to 98 communities (range 0.05-0.50: median = 0.32) and categorized into tertiles (low, middle, high). Depressive symptoms and post-traumatic stress symptoms (PTSS) were assessed in the three post-disaster surveys using validated instruments. Multilevel analysis was conducted adjusting for pre-disaster characteristics.
Higher levels of community income inequality were associated with higher PTSS scores across time (2013: β = 0.14, 95%CI = -0.01, 0.29; 2016: β = 0.16, 95%CI = 0.03, 0.29; 2019: β = 0.12, 95%CI = -0.01, 0.24). The association between income inequality and mental health was partly attenuated by adding the change in social capital to the model (2013: β = 0.14, 95%CI = -0.01, 0.29; 2016: β = 0.15, 95%CI = 0.03, 0.28; 2019: β = 0.11, 95%CI = -0.01, 0.22).
Our findings suggest that pre-disaster income inequality may explain PTSS symptoms in the aftermath of a disaster, and the relation may be mediated by disaster-related change. Further study to reveal its mechanism is needed for the policy recommendation.
我们试图验证这样一个假设，即收入不平等程度较高的社区应对危机的能力较差。具体来说，我们检验了灾难前较高的收入不平等是否会增加灾难后心理健康状况恶化的风险。
我们在一项对 2011 年东日本大地震中幸存的老年人（≥65 岁）的前瞻性队列研究中，检验了灾难前社区收入不平等与灾后心理健康结果之间的关系。参与者的基线调查（在 2010 年完成）比灾难早七个月。幸存者在 2013 年、2016 年和 2019 年完成了三次灾后调查。为了评估收入不平等程度，使用 2010 年个人收入数据计算了基尼指数，这些数据被汇总到 98 个社区（范围 0.05-0.50：中位数=0.32），并分为三分位（低、中、高）。使用经过验证的工具在三次灾后调查中评估抑郁症状和创伤后应激症状（PTSS）。在调整了灾难前特征后，进行了多层次分析。
社区收入不平等程度较高与随时间推移的 PTSS 评分较高有关（2013 年：β=0.14，95%CI=-0.01，0.29；2016 年：β=0.16，95%CI=0.03，0.29；2019 年：β=0.12，95%CI=-0.01，0.24）。通过向模型中添加社会资本变化，收入不平等与心理健康之间的关联部分减弱（2013 年：β=0.14，95%CI=-0.01，0.29；2016 年：β=0.15，95%CI=0.03，0.28；2019 年：β=0.11，95%CI=-0.01，0.22）。
我们的研究结果表明，灾难前的收入不平等可能解释了灾难后的创伤后应激症状，这种关系可能是由与灾难相关的变化介导的。需要进一步的研究来揭示其机制，以提出政策建议。
