Seasonality of mortality under a changing climate: a time-series analysis of mortality in Japan between 1972 and 2015.
10.1186/s12199-021-00992-8
- Author:
Lina MADANIYAZI
1
;
Yeonseung CHUNG
2
;
Yoonhee KIM
3
;
Aurelio TOBIAS
4
;
Chris Fook Sheng NG
4
;
Xerxes SEPOSO
4
;
Yuming GUO
5
;
Yasushi HONDA
6
;
Antonio GASPARRINI
7
;
Ben ARMSTRONG
7
;
Masahiro HASHIZUME
8
Author Information
1. Department of Pediatric Infectious Diseases, Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan.
2. Department of Mathematical Sciences, Korea Advanced Institute of Science and Technology, Daejeon, South Korea.
3. Department of Global Environmental Health, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
4. School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki, Japan.
5. Department of Epidemiology and Preventive Medicine, School of Public Health and Preventive Medicine, Monash University, Melbourne, Australia.
6. Faculty of Health and Sport Sciences, University of Tsukuba, Tsukuba, Japan.
7. Department of Public Health, Environments and Society, London School of Hygiene & Tropical Medicine, London, UK.
8. Department of Pediatric Infectious Diseases, Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan. hashizume@m.u-tokyo.ac.jp.
- Publication Type:Journal Article
- Keywords:
Climate change;
Mortality;
Seasonality;
Temperature
- MeSH:
Cardiovascular Diseases/mortality*;
Cause of Death;
Climate Change/mortality*;
Cold Temperature/adverse effects*;
Hot Temperature/adverse effects*;
Humans;
Japan/epidemiology*;
Mortality/trends*;
Regression Analysis;
Respiratory Tract Diseases/mortality*;
Seasons;
Time
- From:Environmental Health and Preventive Medicine
2021;26(1):69-69
- CountryJapan
- Language:English
-
Abstract:
BACKGROUND:Ambient temperature may contribute to seasonality of mortality; in particular, a warming climate is likely to influence the seasonality of mortality. However, few studies have investigated seasonality of mortality under a warming climate.
METHODS:Daily mean temperature, daily counts for all-cause, circulatory, and respiratory mortality, and annual data on prefecture-specific characteristics were collected for 47 prefectures in Japan between 1972 and 2015. A quasi-Poisson regression model was used to assess the seasonal variation of mortality with a focus on its amplitude, which was quantified as the ratio of mortality estimates between the peak and trough days (peak-to-trough ratio (PTR)). We quantified the contribution of temperature to seasonality by comparing PTR before and after temperature adjustment. Associations between annual mean temperature and annual estimates of the temperature-unadjusted PTR were examined using multilevel multivariate meta-regression models controlling for prefecture-specific characteristics.
RESULTS:The temperature-unadjusted PTRs for all-cause, circulatory, and respiratory mortality were 1.28 (95% confidence interval (CI): 1.27-1.30), 1.53 (95% CI: 1.50-1.55), and 1.46 (95% CI: 1.44-1.48), respectively; adjusting for temperature reduced these PTRs to 1.08 (95% CI: 1.08-1.10), 1.10 (95% CI: 1.08-1.11), and 1.35 (95% CI: 1.32-1.39), respectively. During the period of rising temperature (1.3 °C on average), decreases in the temperature-unadjusted PTRs were observed for all mortality causes except circulatory mortality. For each 1 °C increase in annual mean temperature, the temperature-unadjusted PTR for all-cause, circulatory, and respiratory mortality decreased by 0.98% (95% CI: 0.54-1.42), 1.39% (95% CI: 0.82-1.97), and 0.13% (95% CI: - 1.24 to 1.48), respectively.
CONCLUSION:Seasonality of mortality is driven partly by temperature, and its amplitude may be decreasing under a warming climate.
