Title |
Changes in Susceptibility to Heat During the Summer: A Multicountry Analysis
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Published in |
American Journal of Epidemiology, May 2016
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DOI | 10.1093/aje/kwv260 |
Pubmed ID | |
Authors |
Antonio Gasparrini, Yuming Guo, Masahiro Hashizume, Eric Lavigne, Aurelio Tobias, Antonella Zanobetti, Joel D. Schwartz, Michela Leone, Paola Michelozzi, Haidong Kan, Shilu Tong, Yasushi Honda, Ho Kim, Ben G. Armstrong |
Abstract |
Few studies have examined the variation in mortality risk associated with heat during the summer. Here, we apply flexible statistical models to investigate the issue by using a large multicountry data set. We collected daily time-series data of temperature and mortality from 305 locations in 9 countries, in the period 1985-2012. We first estimated the heat-mortality relationship in each location with time-varying distributed lag non-linear models, using a bivariate spline to model the exposure-lag-response over lag 0-10. Estimates were then pooled by country through multivariate meta-analysis. Results provide strong evidence of a reduction in risk over the season. Relative risks for the 99th percentile versus the minimum mortality temperature were in the range of 1.15-2.03 in early summer. In late summer, the excess was substantially reduced or abated, with relative risks in the range of 0.97-1.41 and indications of wider comfort ranges and higher minimum mortality temperatures. The attenuation is mainly due to shorter lag periods in late summer. In conclusion, this multicountry analysis suggests a reduction of heat-related mortality risk over the summer, which can be attributed to several factors, such as true acclimatization, adaptive behaviors, or harvesting effects. These findings may have implications on public health policies and climate change health impact projections. |
X Demographics
Geographical breakdown
Country | Count | As % |
---|---|---|
Spain | 25 | 45% |
Chile | 1 | 2% |
United Kingdom | 1 | 2% |
Morocco | 1 | 2% |
Australia | 1 | 2% |
United States | 1 | 2% |
Unknown | 26 | 46% |
Demographic breakdown
Type | Count | As % |
---|---|---|
Members of the public | 42 | 75% |
Scientists | 9 | 16% |
Practitioners (doctors, other healthcare professionals) | 3 | 5% |
Science communicators (journalists, bloggers, editors) | 2 | 4% |
Mendeley readers
Geographical breakdown
Country | Count | As % |
---|---|---|
Unknown | 177 | 100% |
Demographic breakdown
Readers by professional status | Count | As % |
---|---|---|
Student > Ph. D. Student | 38 | 21% |
Researcher | 31 | 18% |
Student > Master | 21 | 12% |
Student > Bachelor | 10 | 6% |
Student > Doctoral Student | 9 | 5% |
Other | 23 | 13% |
Unknown | 45 | 25% |
Readers by discipline | Count | As % |
---|---|---|
Environmental Science | 37 | 21% |
Medicine and Dentistry | 27 | 15% |
Earth and Planetary Sciences | 12 | 7% |
Social Sciences | 10 | 6% |
Nursing and Health Professions | 10 | 6% |
Other | 24 | 14% |
Unknown | 57 | 32% |