Rau Austin, Baldomero Arianne K, Bell Jesse E, Rennie Jared, Wendt Chris H, Tarr Gillian A M, Alexander Bruce H, Berman Jesse D
Division of Environmental Health Sciences, University of Minnesota School of Public Health, Minneapolis, Minnesota.
Pulmonary, Allergy, Critical Care, and Sleep Medicine Section, Minneapolis VA Health Care System, Minneapolis, Minnesota.
Environ Epidemiol. 2025 May 1;9(3):e389. doi: 10.1097/EE9.0000000000000389. eCollection 2025 Jun.
Compound extreme weather events are severe weather conditions that can jointly magnify human health risks beyond any single event alone. Drought and heatwaves are extreme weather conditions associated with adverse health, but their combined impact is poorly understood.
We designed a case-crossover study to estimate heatwave-associated mortality stratified by drought conditions in 183,725 US Veteran patients (2016-2021) with chronic obstructive pulmonary disease (COPD). A conditional logistic regression with distributed lag models was applied. Droughts were categorized into binary and categorical metrics, and we further explored the timing of heatwaves as a risk factor.
Our results indicate that drought amplifies heatwaves with hotter temperatures and longer durations during drought conditions, and the percentage of mortality attributable to heatwaves during drought was 7.41% (95% confidence interval [CI]: 2.91, 12.28) compared with 2.91% (95% CI: 0.00, 4.76) for heatwaves during nondrought conditions. Heatwaves that occurred during drought conditions in the late warm season had a larger association with mortality compared with late-season heatwaves during nondrought conditions, 7.41% (95% CI: 1.96, 13.04) of mortality events and 0.99% (95% CI: -1.01, 3.85) of mortality events attributable to these exposures, respectively.
Compound drought and heatwave events trend toward increased mortality risk among patients with COPD and present a growing human health threat under climate change. Existing heat warnings and vulnerability maps may include drought conditions to better capture heat-related public health risks.
复合极端天气事件是指那些严重的天气状况，它们共同加剧的人类健康风险远超任何单一事件的影响。干旱和热浪是与健康不良相关的极端天气状况，但它们的综合影响却鲜为人知。
我们设计了一项病例交叉研究，以估算183,725名患有慢性阻塞性肺疾病（COPD）的美国退伍军人患者（2016 - 2021年）中，按干旱状况分层的热浪相关死亡率。应用了带有分布滞后模型的条件逻辑回归。干旱被分为二元和分类指标，并且我们进一步探究了热浪发生时间作为一个风险因素。
我们的结果表明，干旱会加剧热浪，在干旱期间温度更高且持续时间更长，干旱期间归因于热浪的死亡率百分比为7.41%（95%置信区间[CI]：2.91，12.28），而非干旱期间热浪的这一比例为2.91%（95%CI：0.00，4.76）。与非干旱条件下暖季后期的热浪相比，干旱条件下暖季后期发生的热浪与死亡率的关联更大，这些暴露分别导致7.41%（95%CI：1.96，13.04）和0.99%（95%CI： - 1.01，3.85）的死亡事件。
干旱和热浪复合事件使慢性阻塞性肺疾病患者面临的死亡风险呈上升趋势，并在气候变化下对人类健康构成日益严重的威胁。现有的高温预警和脆弱性地图可能应纳入干旱状况，以更好地捕捉与高温相关的公共卫生风险。
