Longer-Term Impact of High and Low Temperature on Mortality: An International Study to Clarify Length of Mortality Displacement

Armstrong, Ben,Bell, Michelle L.,de Sousa Zanotti Stagliorio Coelho, Micheline,Leon Guo, Yue-Liang,Guo, Yuming,Goodman, Patrick,Hashizume, Masahiro,Honda, Yasushi,Kim, Ho,Lavigne, Eric,Michelozzi, Pao U.S. Dept. of Health, Education, and Welfare, Publ 2017 Environmental health perspectives Vol.125 No.10

<P><B>Background:</B></P><P>In many places, daily mortality has been shown to increase after days with particularly high or low temperatures, but such daily time-series studies cannot identify whether such increases reflect substantial life shortening or short-term displacement of deaths (harvesting).</P><P><B>Objectives:</B></P><P>To clarify this issue, we estimated the association between annual mortality and annual summaries of heat and cold in 278 locations from 12 countries.</P><P><B>Methods:</B></P><P>Indices of annual heat and cold were used as predictors in regressions of annual mortality in each location, allowing for trends over time and clustering of annual count anomalies by country and pooling estimates using meta-regression. We used two indices of annual heat and cold based on preliminary standard daily analyses: <I>a</I>) mean annual degrees above/below minimum mortality temperature (MMT), and <I>b</I>) estimated fractions of deaths attributed to heat and cold. The first index was simpler and matched previous related research; the second was added because it allowed the interpretation that coefficients equal to 0 and 1 are consistent with none (0) or all (1) of the deaths attributable in daily analyses being displaced by at least 1 y.</P><P><B>Results:</B></P><P>On average, regression coefficients of annual mortality on heat and cold mean degrees were 1.7% [95% confidence interval (CI): 0.3, 3.1] and 1.1% (95% CI: 0.6, 1.6) per degree, respectively, and daily attributable fractions were 0.8 (95% CI: 0.2, 1.3) and 1.1 (95% CI: 0.9, 1.4). The proximity of the latter coefficients to 1.0 provides evidence that most deaths found attributable to heat and cold in daily analyses were brought forward by at least 1 y. Estimates were broadly robust to alternative model assumptions.</P><P><B>Conclusions:</B></P><P>These results provide strong evidence that most deaths associated in daily analyses with heat and cold are displaced by at least 1 y. https://doi.org/10.1289/EHP1756</P>

Heat Wave and Mortality: A Multicountry, Multicommunity Study

Guo, Yuming,Gasparrini, Antonio,Armstrong, Ben G.,Tawatsupa, Benjawan,Tobias, Aurelio,Lavigne, Eric,Coelho, Micheline de Sousa Zanotti Stagliorio,Pan, Xiaochuan,Kim, Ho,Hashizume, Masahiro,Honda, Yasu Environmental Health Perspectives 2017 Environmental health perspectives Vol.125 No.8

<P><B>Background:</B></P><P>Few studies have examined variation in the associations between heat waves and mortality in an international context.</P><P><B>Objectives:</B></P><P>We aimed to systematically examine the impacts of heat waves on mortality with lag effects internationally.</P><P><B>Methods:</B></P><P>We collected daily data of temperature and mortality from 400 communities in 18 countries/regions and defined 12 types of heat waves by combining community-specific daily mean temperature [FORMULA OMISSION], 92.5th, 95th, and 97.5th percentiles of temperature with duration [FORMULA OMISSION], 3, and 4 d. We used time-series analyses to estimate the community-specific heat wave–mortality relation over lags of 0–10 d. Then, we applied meta-analysis to pool heat wave effects at the country level for cumulative and lag effects for each type of heat wave definition.</P><P><B>Results:</B></P><P>Heat waves of all definitions had significant cumulative associations with mortality in all countries, but varied by community. The higher the temperature threshold used to define heat waves, the higher heat wave associations on mortality. However, heat wave duration did not modify the impacts. The association between heat waves and mortality appeared acutely and lasted for 3 and 4 d. Heat waves had higher associations with mortality in moderate cold and moderate hot areas than cold and hot areas. There were no added effects of heat waves on mortality in all countries/regions, except for Brazil, Moldova, and Taiwan. Heat waves defined by daily mean and maximum temperatures produced similar heat wave–mortality associations, but not daily minimum temperature.</P><P><B>Conclusions:</B></P><P>Results indicate that high temperatures create a substantial health burden, and effects of high temperatures over consecutive days are similar to what would be experienced if high temperature days occurred independently. People living in moderate cold and moderate hot areas are more sensitive to heat waves than those living in cold and hot areas. Daily mean and maximum temperatures had similar ability to define heat waves rather than minimum temperature. https://doi.org/10.1289/EHP1026</P>

Mortality burden of diurnal temperature range and its temporal changes: A multi-country study

Lee, Whanhee,Bell, Michelle L.,Gasparrini, Antonio,Armstrong, Ben G.,Sera, Francesco,Hwang, Sunghee,Lavigne, Eric,Zanobetti, Antonella,Coelho, Micheline de Sousa Zanotti Stagliorio,Saldiva, Paulo Hila Elsevier 2018 Environment international Vol.110 No.-

<P><B>Abstract</B></P> <P>Although diurnal temperature range (DTR) is a key index of climate change, few studies have reported the health burden of DTR and its temporal changes at a multi-country scale. Therefore, we assessed the attributable risk fraction of DTR on mortality and its temporal variations in a multi-country data set. We collected time-series data covering mortality and weather variables from 308 cities in 10 countries from 1972 to 2013. The temporal change in DTR-related mortality was estimated for each city with a time-varying distributed lag model. Estimates for each city were pooled using a multivariate meta-analysis. The results showed that the attributable fraction of total mortality to DTR was 2.5% (95% eCI: 2.3–2.7%) over the entire study period. In all countries, the attributable fraction increased from 2.4% (2.1–2.7%) to 2.7% (2.4–2.9%) between the first and last study years. This study found that DTR has significantly contributed to mortality in all the countries studied, and this attributable fraction has significantly increased over time in the USA, the UK, Spain, and South Korea. Therefore, because the health burden of DTR is not likely to reduce in the near future, countermeasures are needed to alleviate its impact on human health.</P> <P><B>Highlights</B></P> <P> <UL> <LI> We analyzed the health burden of diurnal temperature range (DTR) for 10 countries. </LI> <LI> In addition, we estimated the temporal changes in the mortality burden of DTR. </LI> <LI> The excessive risk and attributable risk of DTR was significant in most countries. </LI> <LI> The mortality burden due to DTR has been increased during decades (1972–2013). </LI> <LI> We conclude that the effect of DTR will not decrease in the near future. </LI> </UL> </P>

A multi-country analysis on potential adaptive mechanisms to cold and heat in a changing climate

Vicedo-Cabrera, Ana M.,Sera, Francesco,Guo, Yuming,Chung, Yeonseung,Arbuthnott, Katherine,Tong, Shilu,Tobias, Aurelio,Lavigne, Eric,de Sousa Zanotti Stagliorio Coelho, Micheline,Hilario Nascimento Sal Elsevier 2018 Environment international Vol.111 No.-

<P><B>Abstract</B></P> <P><B>Background</B></P> <P>Temporal variation of temperature-health associations depends on the combination of two pathways: pure adaptation to increasingly warmer temperatures due to climate change, and other attenuation mechanisms due to non-climate factors such as infrastructural changes and improved health care. Disentangling these pathways is critical for assessing climate change impacts and for planning public health and climate policies. We present evidence on this topic by assessing temporal trends in cold- and heat-attributable mortality risks in a multi-country investigation.</P> <P><B>Methods</B></P> <P>Trends in country-specific attributable mortality fractions (AFs) for cold and heat (defined as below/above minimum mortality temperature, respectively) in 305 locations within 10 countries (1985–2012) were estimated using a two-stage time-series design with time-varying distributed lag non-linear models. To separate the contribution of pure adaptation to increasing temperatures and active changes in susceptibility (non-climate driven mechanisms) to heat and cold, we compared observed yearly-AFs with those predicted in two counterfactual scenarios: trends driven by either (1) changes in exposure-response function (assuming a constant temperature distribution), (2) or changes in temperature distribution (assuming constant exposure-response relationships). This comparison provides insights about the potential mechanisms and pace of adaptation in each population.</P> <P><B>Results</B></P> <P>Heat-related AFs decreased in all countries (ranging from 0.45–1.66% to 0.15–0.93%, in the first and last 5-year periods, respectively) except in Australia, Ireland and UK. Different patterns were found for cold (where AFs ranged from 5.57–15.43% to 2.16–8.91%), showing either decreasing (Brazil, Japan, Spain, Australia and Ireland), increasing (USA), or stable trends (Canada, South Korea and UK). Heat-AF trends were mostly driven by changes in exposure-response associations due to modified susceptibility to temperature, whereas no clear patterns were observed for cold.</P> <P><B>Conclusions</B></P> <P>Our findings suggest a decrease in heat-mortality impacts over the past decades, well beyond those expected from a pure adaptation to changes in temperature due to the observed warming. This indicates that there is scope for the development of public health strategies to mitigate heat-related climate change impacts. In contrast, no clear conclusions were found for cold. Further investigations should focus on identification of factors defining these changes in susceptibility.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Evidence on adaptation is crucial for the assessment of climate change impacts. </LI> <LI> Most of the studied countries showed a strong reduction in heat vulnerability. </LI> <LI> We found more diffuse patterns on cold-mortality trends. </LI> <LI> Pace of decrease in heat susceptibility was faster than the observed warming. </LI> <LI> There is scope for development of mitigation strategies of climate change impacts. </LI> </UL> </P>

Predicted temperature-increase-induced global health burden and its regional variability

Lee, Jae Young,Kim, Ho,Gasparrini, Antonio,Armstrong, Ben,Bell, Michelle L.,Sera, Francesco,Lavigne, Eric,Abrutzky, Rosana,Tong, Shilu,Coelho, Micheline de Sousa Zanotti Stagliorio,Saldiva, Paulo Hila Elsevier 2019 Environment international Vol.131 No.-

<P><B>Abstract</B></P> <P>An increase in the global health burden of temperature was projected for 459 locations in 28 countries worldwide under four representative concentration pathway scenarios until 2099. We determined that the amount of temperature increase for each 100 ppm increase in global CO<SUB>2</SUB> concentrations is nearly constant, regardless of climate scenarios. The overall average temperature increase during 2010–2099 is largest in Canada (1.16 °C/100 ppm) and Finland (1.14 °C/100 ppm), while it is smallest in Ireland (0.62 °C/100 ppm) and Argentina (0.63 °C/100 ppm). In addition, for each 1 °C temperature increase, the amount of excess mortality is increased largely in tropical countries such as Vietnam (10.34%p/°C) and the Philippines (8.18%p/°C), while it is decreased in Ireland (−0.92%p/°C) and Australia (−0.32%p/°C). To understand the regional variability in temperature increase and mortality, we performed a regression-based modeling. We observed that the projected temperature increase is highly correlated with daily temperature range at the location and vulnerability to temperature increase is affected by health expenditure, and proportions of obese and elderly population.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Future health burden with respect to CO<SUB>2</SUB> increase was projected in 28 countries. </LI> <LI> Future temperature and mortality were compared across locations. </LI> <LI> Daily temperature range determines the rate of temperature increase. </LI> <LI> Amount of health expenditure determines the vulnerability to temperature change. </LI> </UL> </P>