Temperature Variability and Mortality: A Multi-Country Study.
BACKGROUND
The evidence and method are limited for the associations between mortality and temperature variability (TV) within or between days.


OBJECTIVE
We developed a novel method to calculate TV and investigated TV-mortality associations using a large multicountry data set.


METHODS
We collected daily data for temperature and mortality from 372 locations in 12 countries/regions (Australia, Brazil, Canada, China, Japan, Moldova, South Korea, Spain, Taiwan, Thailand, the United Kingdom, and the United States). We calculated TV from the standard deviation of the minimum and maximum temperatures during the exposure days. Two-stage analyses were used to assess the relationship between TV and mortality. In the first stage, a Poisson regression model allowing over-dispersion was used to estimate the community-specific TV-mortality relationship, after controlling for potential confounders. In the second stage, a meta-analysis was used to pool the effect estimates within each country.


RESULTS
There was a significant association between TV and mortality in all countries, even after controlling for the effects of daily mean temperature. In stratified analyses, TV was still significantly associated with mortality in cold, hot, and moderate seasons. Mortality risks related to TV were higher in hot areas than in cold areas when using short TV exposures (0-1 days), whereas TV-related mortality risks were higher in moderate areas than in cold and hot areas when using longer TV exposures (0-7 days).


CONCLUSIONS
The results indicate that more attention should be paid to unstable weather conditions in order to protect health. These findings may have implications for developing public health policies to manage health risks of climate change.


BACKGROUND
Guo Y, Gasparrini A, Armstrong BG, Tawatsupa B, Tobias A, Lavigne E, Coelho MS, Pan X, Kim H, Hashizume M, Honda Y, Guo YL, Wu CF, Zanobetti A, Schwartz JD, Bell ML, Overcenco A, Punnasiri K, Li S, Tian L, Saldiva P, Williams G, Tong S. 2016. Temperature variability and mortality: a multi-country study. Environ Health Perspect 124:1554-1559; http://dx.doi.org/10.1289/EHP149.
Department of Epidemiology and Biostatistics, School of Public Health, University of Queensland, Brisbane, Australia.
Yuming
Y
Guo
Antonio
A
Gasparrini
Ben G
BG
Armstrong
Benjawan
B
Tawatsupa
Aurelio
A
Tobias
Eric
E
Lavigne
Micheline de Sousa Zanotti Stagliorio
MS
Coelho
Xiaochuan
X
Pan
Ho
H
Kim
Masahiro
M
Hashizume
Yasushi
Y
Honda
Yue Leon
YL
Guo
Chang-Fu
CF
Wu
Antonella
A
Zanobetti
Joel D
JD
Schwartz
Michelle L
ML
Bell
Ala
A
Overcenco
Kornwipa
K
Punnasiri
Shanshan
S
Li
Linwei
L
Tian
Paulo
P
Saldiva
Gail
G
Williams
Shilu
S
Tong