Seasonal characteristics of temperature variability impacts on childhood asthma hospitalization in Hefei, China: Does PM2.5 modify the association?

Shuangshuang Yan; Xu Wang; Zhenhai Yao; Jian Cheng; Hong Ni; Zhiwei Xu; Qiannan Wei; Rubing Pan; Weizhuo Yi; Xiaoyu Jin; Chao Tang; Xiangguo Liu; Yangyang He; Yudong Wu; Yuxuan Li; Xiaoni Sun; Yunfeng Liang; Lu Mei; Hong Su

doi:10.1016/j.envres.2021.112078

Seasonal characteristics of temperature variability impacts on childhood asthma hospitalization in Hefei, China: Does PM_2.5 modify the association?

Environ Res. 2022 May 1:207:112078. doi: 10.1016/j.envres.2021.112078. Epub 2021 Sep 29.

Authors

Shuangshuang Yan¹, Xu Wang², Zhenhai Yao³, Jian Cheng¹, Hong Ni², Zhiwei Xu⁴, Qiannan Wei¹, Rubing Pan¹, Weizhuo Yi¹, Xiaoyu Jin¹, Chao Tang¹, Xiangguo Liu¹, Yangyang He¹, Yudong Wu¹, Yuxuan Li¹, Xiaoni Sun¹, Yunfeng Liang¹, Lu Mei¹, Hong Su⁵

Affiliations

¹ Department of Epidemiology and Health Statistics, School of Public Health, Anhui Medical University, Hefei, Anhui, 230032, China; Anhui Province Key Laboratory of Major Autoimmune Disease, China.
² Anhui Provincial Children's Hospital, China.
³ Anhui Public Meteorological Service Center, Hefei, Anhui, 230011, China.
⁴ School of Public Health, Faculty of Medicine, University of Queensland, Brisbane, Australia.
⁵ Department of Epidemiology and Health Statistics, School of Public Health, Anhui Medical University, Hefei, Anhui, 230032, China; Anhui Province Key Laboratory of Major Autoimmune Disease, China. Electronic address: suhong5151@sina.com.

PMID: 34599899
DOI: 10.1016/j.envres.2021.112078

Abstract

Objectives: Evidence of childhood asthma hospitalizations associated with temperature variability (TV) and the attributable risk are limited in China. We aim to use a comprehensive index that reflected both intra- and inter-day TV to assess the TV-childhood asthma relationship and disease burden, further to identify seasonality vulnerable populations, and to explore the effect modification of PM_2.5.

Methods: A quasi-distributed lagged nonlinear model (DLNM) combined with a linear threshold function was applied to estimate the association between TV and childhood asthma hospitalizations during 2013-2016 in Hefei, China. Subgroup analysis was conducted by age and sex. Disease burden is reflected by the attributable fraction and attributable number. Besides, modifications of PM_2.5 were tested by introducing the cross-basis of TV and binary PM_2.5 as an interaction term.

Results: The risk estimates peaked at TV_0-3 and TV_0-4 in the cool and the warm season separately, with RR of 1.051 (95%CI: 1.021-1.081) and 1.072 (95%CI: 1.008-1.125), and the effects lasted longer in the cool season. The school-age children in the warm season and all subgroups except pre-school children in the cool season were vulnerable to TV. It is estimated that the disease burden related to TV account for 6.2% (95% CI: 2.7%-9.4%) and 4% (95% CI: 0.6%-7.1%) during the cool and warm seasons in TV_0-3. In addition, the risks of TV were higher under the high PM_2.5 level compared with the low PM_2.5 level in the cool season, although no significant differences between them.

Conclusions: TV exposure significantly increases the risk and disease burden of childhood asthma hospitalizations, especially in the cool season. More medical resources should be allocated to school-age children. Giving priority to pay attention to TV in the cool season in practice could obtain the greatest public health benefits and those days with high TV and high PM_2.5 need more attention.

Keywords: Attributable risk; Childhood asthma; Effect modification; Seasonality; Temperature variability.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Air Pollutants* / analysis
Air Pollution* / analysis
Asthma* / epidemiology
Child
Child, Preschool
China / epidemiology
Environmental Exposure / analysis
Hospitalization
Humans
Particulate Matter / analysis
Risk Factors
Seasons
Temperature

Substances

Air Pollutants
Particulate Matter