Department of Geomatics, National Cheng Kung University, Tainan, Taiwan.
Institute of Population Health Sciences, National Health Research Institutes, Miaoli County, Taiwan.
Front Public Health. 2022 Jul 5;10:902480. doi: 10.3389/fpubh.2022.902480. eCollection 2022.
This study applied an ecological-based analysis aimed to evaluate on a global scale the association between greenness exposure and suicide mortality.
Suicide mortality data provided by the Institute for Health Metrics and Evaluation and the Normalized Difference Vegetation Index (NDVI) were employed. The generalized additive mixed model was applied to evaluate with an adjustment of covariates the association between greenness and suicide mortality. Sensitivity tests and positive-negative controls also were used to examine less overt insights. Subgroup analyses were then conducted to investigate the effects of greenness on suicide mortality among various conditions.
The main finding of this study indicates a negative association between greenness exposure and suicide mortality, as greenness significantly decreases the risk of suicide mortality per interquartile unit increment of NDVI (relative risk = 0.69, 95%CI: 0.59-0.81). Further, sensitivity analyses confirmed the robustness of the findings. Subgroup analyses also showed a significant negative association between greenness and suicide mortality for various stratified factors, such as sex, various income levels, urbanization levels, etc.
Greenness exposure may contribute to a reduction in suicide mortality. It is recommended that policymakers and communities increase environmental greenness in order to mitigate the global health burden of suicide.
本研究采用基于生态学的分析方法，旨在从全球范围评估绿色暴露与自杀死亡率之间的关联。
本研究采用了自杀死亡率数据，这些数据来自健康指标与评估研究所和归一化植被指数（NDVI）。采用广义加性混合模型，在调整协变量的情况下，评估绿色与自杀死亡率之间的关联。还进行了敏感性测试和正负对照，以检验不太明显的见解。然后进行了亚组分析，以调查绿色对不同条件下自杀死亡率的影响。
本研究的主要发现表明，绿色暴露与自杀死亡率之间呈负相关，因为绿色每增加一个 NDVI 四分位间距单位，自杀死亡率的风险就会显著降低（相对风险=0.69，95%CI：0.59-0.81）。此外，敏感性分析证实了研究结果的稳健性。亚组分析还表明，绿色与自杀死亡率之间存在显著的负相关，这种关联在性别、各种收入水平、城市化水平等各种分层因素中都存在。
绿色暴露可能有助于降低自杀死亡率。建议政策制定者和社区增加环境绿色度，以减轻全球自杀带来的健康负担。
