Differentiating the impacts of ambient temperature on pneumonia mortality of various infectious causes: a nationwide, individual-level, case-crossover study

Qinglin He; Yunning Liu; Peng Yin; Ya Gao; Haidong Kan; Maigeng Zhou; Renjie Chen; Yanming Li

doi:10.1016/j.ebiom.2023.104854

Differentiating the impacts of ambient temperature on pneumonia mortality of various infectious causes: a nationwide, individual-level, case-crossover study

EBioMedicine. 2023 Dec:98:104854. doi: 10.1016/j.ebiom.2023.104854. Epub 2023 Oct 28.

Authors

Qinglin He¹, Yunning Liu², Peng Yin², Ya Gao¹, Haidong Kan¹, Maigeng Zhou², Renjie Chen³, Yanming Li⁴

Affiliations

¹ School of Public Health, Key Lab of Public Health Safety of the Ministry of Education and NHC Key Laboratory of Health Technology Assessment, Fudan University, Shanghai, 200032, China.
² National Center for Chronic Non-communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, 100050, China.
³ School of Public Health, Key Lab of Public Health Safety of the Ministry of Education and NHC Key Laboratory of Health Technology Assessment, Fudan University, Shanghai, 200032, China. Electronic address: chenrenjie@fudan.edu.cn.
⁴ Department of Respiratory and Critical Care Medicine, Beijing Hospital, National Center of Gerontology, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing, 100730, China. Electronic address: liyanming2632@bjhmoh.cn.

Abstract

Background: It remains unknown how ambient temperature impact pneumonia of various infectious causes.

Methods: Based on the national death registry covering all counties in Chinese mainland, we conducted an individual-level case-crossover study in China from 2013 to 2019. Exposures were assigned at residential addresses for each decedent. Conditional logistic regression model combined with distributed lag non-linear models were used to estimate the exposure-response associations. The attributable fractions due to non-optimum temperature were calculated after accounting for spatial and temporal patterns for the excess risks.

Findings: The exposure-response curves were inversely J-shaped with both low and high temperature increasing the risks, and the effect of low temperature was stronger. Extremely low temperature was associated with higher magnitude of influenza-related pneumonia [relative risk (RR): 2.46, 95% confidence interval (CI): 1.62-3.74], than viral pneumonia (RR: 1.89, 95% CI: 1.55-2.30) and bacterial pneumonia (RR: 1.81, 95% CI: 1.56-2.09). The magnitudes of RRs associated with extremely high temperature were similar among the three categories of pneumonia. The mortality attributable fraction for influenza-related pneumonia (29.78%) was the highest. The effects were stronger in people of low education level or residence in the north.

Interpretation: This nationwide study presents findings on the varied risk and burden of pneumonia mortality of various infectious causes, and highlights the susceptibility of influenza-related pneumonia to ambient low temperature.

Funding: This study is supported by the National Key Research and Development Program (2022YFC3702701), the Shanghai Municipal Science and Technology Commission (21TQ015) and Shanghai International Science and Technology Partnership Project (21230780200).

Keywords: Ambient temperature; Attributable fraction; Case-crossover study; Infectious diseases; Pneumonia.

MeSH terms

China / epidemiology
Communicable Diseases*
Cross-Over Studies
Humans
Influenza, Human* / epidemiology
Pneumonia, Viral*
Temperature