Kyoto University School of Public Health, Kyoto, Japan.
Front Public Health. 2023 Sep 22;11:1184963. doi: 10.3389/fpubh.2023.1184963. eCollection 2023.
Heatstroke mortality is highest among older adults aged 65 years and older, and the risk is even doubled among those aged 75 years and older. The incidence of heatstroke is expected to increase in the future with elevated temperatures owing to climate change. In the context of a super-aged society, we examined possible adaptation measures in Japan that could prevent heatstroke among older people using an epidemiological survey combined with mathematical modeling.
To identify possible interventions, we conducted a cross-sectional survey, collecting information on heatstroke episodes from 2018 to 2019 among people aged 75 years and older. Responses were analyzed from 576 participants, and propensity score matching was used to adjust for measurable confounders and used to estimate the effect sizes associated with variables that constitute possible interventions. Subsequently, a weather-driven statistical model was used to predict heatstroke-related ambulance transports. We projected the incidence of heatstroke-related transports until the year 2100, with and without adaptation measures.
The risk factor with the greatest odds ratio (OR) of heatstroke among older adults was living alone (OR 2.5, 95% confidence interval: 1.2-5.4). Other possible risk factors included an inability to drink water independently and the absence of air conditioning. Using three climate change scenarios, a more than 30% increase in the incidence of heatstroke-related ambulance transports was anticipated for representative concentration pathways (RCP) 4.5 and 8.5, as compared with a carbon-neutral scenario. Given 30% reduction in single living, a 15% reduction in the incidence of heatstroke is expected. Given 70% improvement in all three risk factors, a 40% reduction in the incidence can be expected.
Possible adaptation measures include providing support for older adults living alone, for those who have an inability to drink water and for those without air conditioning. To be comparable to carbon neutrality, future climate change under RCP 2.6 requires achieving a 30% relative reduction in all three identified risks at least from 2060; under RCP 4.5, a 70% reduction from 2050 at the latest is needed. In the case of RCP 8.5, the goal of heatstroke-related transports approaching RCP 1.9 cannot be achieved.
老年人中，65 岁及以上人群的中暑死亡率最高，而 75 岁及以上人群的中暑风险甚至增加了一倍。随着气候变化导致气温升高，预计未来中暑的发病率将会增加。在超老龄化社会的背景下，我们使用流行病学调查和数学建模相结合的方法，研究了日本可能采取的预防老年人中暑的适应措施。
为了确定可能的干预措施，我们进行了一项横断面调查，收集了 2018 年至 2019 年 75 岁及以上人群中暑发作的信息。共分析了 576 名参与者的回复，并采用倾向评分匹配来调整可测量的混杂因素，并用于估计与可能的干预措施相关的变量的效应大小。随后，使用天气驱动的统计模型来预测与中暑相关的救护车转运。我们预测了 2100 年之前，在没有和有适应措施的情况下，与中暑相关的救护车转运的发病率。
老年人中暑的最大优势比（OR）风险因素是独居（OR 2.5，95%置信区间：1.2-5.4）。其他可能的风险因素包括无法独立饮水和没有空调。使用三种气候变化情景，与碳中性情景相比，代表浓度路径（RCP）4.5 和 8.5 预计中暑相关救护车转运的发病率将增加 30%以上。如果独居人口减少 30%，预计中暑发病率将降低 15%。如果所有三个风险因素都得到 70%的改善，则预计发病率将降低 40%。
可能的适应措施包括为独居的老年人、无法饮水的老年人和没有空调的老年人提供支持。为了与碳中性相比，在 RCP 2.6 下未来的气候变化需要至少从 2060 年开始将所有三个确定的风险降低 30%；在 RCP 4.5 下，最晚需要从 2050 年开始降低 70%。在 RCP 8.5 的情况下，不可能实现与 RCP 1.9 相关的中暑相关转运目标。
