The modification effect of the diurnal temperature range on the exposure-response relationship between temperature and pediatric hand, foot and mouth disease

Yifan Hu; Fengfeng Liu; Xing Zhao; Yue Ma; Tianjiao Lan; Fan Yang; Zhaorui Chang; Xiong Xiao; Zhongjie Li

doi:10.1016/j.scitotenv.2020.137921

The modification effect of the diurnal temperature range on the exposure-response relationship between temperature and pediatric hand, foot and mouth disease

Sci Total Environ. 2020 Jun 20:722:137921. doi: 10.1016/j.scitotenv.2020.137921. Epub 2020 Mar 13.

Authors

Yifan Hu¹, Fengfeng Liu², Xing Zhao¹, Yue Ma¹, Tianjiao Lan¹, Fan Yang¹, Zhaorui Chang³, Xiong Xiao⁴, Zhongjie Li²

Affiliations

¹ Department of Epidemiology and Biostatistics, West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, China.
² Division of Infectious Disease & Key Laboratory of Surveillance and Early Warning on Infectious Disease, Chinese Center for Disease Control and Prevention, Beijing, China.
³ Division of Infectious Disease & Key Laboratory of Surveillance and Early Warning on Infectious Disease, Chinese Center for Disease Control and Prevention, Beijing, China. Electronic address: changzr@chinacdc.cn.
⁴ Department of Epidemiology and Biostatistics, West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, China. Electronic address: xiaoxiong.scu@scu.edu.cn.

PMID: 32208268
DOI: 10.1016/j.scitotenv.2020.137921

Abstract

Background: Growing evidence suggests that the diurnal temperature range (DTR) could modify the temperature-disease relationship for those environmentally-related infectious diseases. However, there is a lack of evidence on the hand, foot and mouth disease (HFMD). In this study, we thoroughly examined this hypothesis via a nationwide study.

Method: We collected the daily time series of HFMD cases and meteorological factors of 143 cities in mainland China from 2009 to 2014. For each city, we calculated the arithmetic average of the meteorological factors as a proxy for the climatic differences. We then performed two-stage time series analyses for four different climatic regions. Specifically, a distributed lag nonlinear model was applied to estimate the temperature-HFMD relationship for each city, and then a multivariate meta-regression was implemented to examine whether the DTR could explain the potential heterogeneity as an effect modifier. In addition, we compared the modification effect of the DTR with those of other climatic factors.

Result: We found a significant modification effect of DTR on the temperature-HFMD relationship in the moderate-temperature region. Besides, the modification effect was only observed at hot temperatures. Comparing the maximum temperature (32.2 °C) to the median temperature (11.9 °C), the risk ratio was 1.60 (1.33, 1.92) when DTR was in the 10th percentile (6.8 °C) and 0.81 (0.69, 0.96) when the DTR was in the 90th percentile (11.8 °C). By comparing DTR with other climatic variables, we found that the DTR had the best performance in improving the model fit (ΔQAIC= 10.1) and reducing the heterogeneity (ΔI² = 3.1%) in the multivariate meta-regression.

Conclusion: Our findings verified that DTR can modify the temperature-HFMD relationship. Besides, our findings also implied that DTR could be used as a proxy variable to comprehensively reflect the modification effects of multiple climatic factors.

Keywords: Diurnal temperature range; Hand, foot and mouth disease; Modification effect; Multicity study; Temperature-HFMD association.

MeSH terms

Child
China
Cities
Hand, Foot and Mouth Disease*
Humans
Incidence
Temperature