MRC Centre for Environment and Health, Department of Epidemiology and Biostatistics, School of Public Health, Imperial College London, London, UK
National Heart and Lung Institute, Imperial College London, London, UK.
Thorax. 2023 Sep;78(9):875-881. doi: 10.1136/thorax-2022-219901. Epub 2023 Apr 17.
Previous studies have reported an association between warm temperature and asthma hospitalisation. They have reported different sex-related and age-related vulnerabilities; nevertheless, little is known about how this effect has changed over time and how it varies in space. This study aims to evaluate the association between asthma hospitalisation and warm temperature and investigate vulnerabilities by age, sex, time and space.
We retrieved individual-level data on summer asthma hospitalisation at high temporal (daily) and spatial (postcodes) resolutions during 2002-2019 in England from the NHS Digital. Daily mean temperature at 1 km×1 km resolution was retrieved from the UK Met Office. We focused on lag 0-3 days. We employed a case-crossover study design and fitted Bayesian hierarchical Poisson models accounting for possible confounders (rainfall, relative humidity, wind speed and national holidays).
After accounting for confounding, we found an increase of 1.11% (95% credible interval: 0.88% to 1.34%) in the asthma hospitalisation risk for every 1°C increase in the ambient summer temperature. The effect was highest for males aged 16-64 (2.10%, 1.59% to 2.61%) and during the early years of our analysis. We also found evidence of a decreasing linear trend of the effect over time. Populations in Yorkshire and the Humber and East and West Midlands were the most vulnerable.
This study provides evidence of an association between warm temperature and hospital admission for asthma. The effect has decreased over time with potential explanations including temporal differences in patterns of heat exposure, adaptive mechanisms, asthma management, lifestyle, comorbidities and occupation.
先前的研究报告称，温暖的气温与哮喘住院之间存在关联。这些研究报告了不同性别和年龄相关的脆弱性；然而，对于这种效应随时间的变化以及在空间上的变化方式，我们知之甚少。本研究旨在评估哮喘住院与高温之间的关联，并研究年龄、性别、时间和空间方面的脆弱性。
我们从 NHS Digital 检索了 2002 年至 2019 年期间英格兰夏季哮喘住院的个体水平数据，具有高时间（每日）和空间（邮政编码）分辨率。从英国气象局检索了 1 公里×1 公里分辨率的每日平均温度。我们重点关注滞后 0-3 天。我们采用病例交叉研究设计，并拟合贝叶斯分层泊松模型，以考虑可能的混杂因素（降雨量、相对湿度、风速和全国性假日）。
在考虑混杂因素后，我们发现夏季环境温度每升高 1°C，哮喘住院风险增加 1.11%（95%可信区间：0.88%至 1.34%）。对于 16-64 岁的男性和我们分析的早期，这种影响最大，为 2.10%（1.59%至 2.61%）。我们还发现随着时间的推移，效应呈下降线性趋势的证据。约克郡和亨伯地区以及东米德兰兹和西米德兰兹的人口最脆弱。
本研究提供了温暖气温与哮喘住院之间存在关联的证据。随着时间的推移，这种效应已经减弱，可能的解释包括热暴露模式的时间差异、适应机制、哮喘管理、生活方式、合并症和职业。
