Kino Shiho, Aida Jun, Kondo Katsunori, Kawachi Ichiro
Department of Oral Health Promotion, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan.
Department of Social Preventive Medical Sciences, Chiba University, Center for Preventive Medical Sciences, Chiba, Japan.
Int J Disaster Risk Reduct. 2023 Nov;98. doi: 10.1016/j.ijdrr.2023.104071. Epub 2023 Oct 19.
Disasters can exacerbate socioeconomic health disparities because of differential exposure (e.g., socioeconomically disadvantaged groups are more likely to be exposed to disaster-related trauma) and differential vulnerability (disadvantaged groups are more likely to suffer health consequences of exposure to trauma). We sought to test whether health disparities among older adults widened in the area which was directly affected by the 2011 Great East Japan Earthquake & Tsunami compared to areas which largely escaped tsunami damage. We used data from a cohort of community-dwelling older adults who were directly affected by the 2011 disaster (the Iwanuma Study) and municipalities that were not directly affected (the JAGES parent cohort excluding Iwanuma city). The Iwanuma Study gathered pre-disaster information from participants in 2010 (seven months before the disaster) as well as post-disaster information in 2013, 2016 and 2019 (2.5, 5.5 and 8.5 years after the disaster). Our outcomes were depressive symptoms (GDS) and instrumental activities of daily living (IADL). We examined the pre- versus post-disaster trends in socioeconomic health disparities using the slope index and relative index of inequality. We then conducted a difference-in-difference analysis comparing the pre/post disaster change in health disparities in the "exposed" city (Iwanuma) compared to "control" cities. We found clear pre-disaster socioeconomic inequalities in both GDS and IADL in both the exposed and control cities. However, the magnitude of these inequalities did not change after the disaster on either the absolute or relative scales. The 2011 disaster in northeastern Japan did not exacerbate pre-existing patterns of health inequalities in the older population.
灾害会加剧社会经济方面的健康差距，这是因为暴露情况存在差异（例如，社会经济地位不利的群体更有可能遭受与灾害相关的创伤）以及脆弱性不同（弱势群体更有可能承受遭受创伤所带来的健康后果）。我们试图检验，与基本未受海啸破坏的地区相比，2011年东日本大地震及海啸直接影响地区的老年人健康差距是否有所扩大。我们使用了两组数据，一组来自于2011年灾害直接影响的社区居住老年人队列（石卷研究），另一组来自未受直接影响的市町村（日本老年学和老年医学学会（JAGES）的总体队列，不包括石卷市）。石卷研究收集了2010年（灾害发生前七个月）参与者的灾前信息以及2013年、2016年和2019年（灾害发生后2.5年、5.5年和8.5年）的灾后信息。我们的研究结果指标为抑郁症状（老年抑郁量表（GDS））和日常生活工具性活动能力（IADL）。我们使用不平等斜率指数和相对指数，研究了灾前与灾后社会经济健康差距的变化趋势。然后，我们进行了双重差分分析，比较了“受影响”城市（石卷）与“对照”城市在健康差距方面的灾后与灾前变化。我们发现，在暴露组城市和对照组城市中，灾前在老年抑郁量表和日常生活工具性活动能力方面均存在明显的社会经济不平等。然而，无论是从绝对尺度还是相对尺度来看，这些不平等的程度在灾后均未改变。2011年日本东北部的灾害并未加剧老年人群中先前存在的健康不平等模式。
