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Modifying Effect of Heat Waves on the Relationship between Temperature and Mortality.

Lee WK, Lee HA, Park H - J. Korean Med. Sci. (2016)

Bottom Line: The effect of temperature on mortality was the greatest in 1991-1995 in Seoul; no significant change was observed in Busan.Furthermore, heterogeneity was found in the modifying effect of heat waves on heat-related mortality in inland and coastal cities.The findings of this study help understand relations between temperature and mortality.

View Article: PubMed Central - PubMed

Affiliation: Department of Social and Preventive Medicine, Inha University School of Medicine, Incheon, Korea .

ABSTRACT
Studies conducted to evaluate temporal trends of heat-related mortality have not considered the effects of heat waves; although it is known they can affect mortality and act as a modifying factor. After adjusting for long-term trends and seasonality, the effects of temperature on non-accidental deaths in Seoul and Busan (inland and coastal cities, respectively) were analyzed using a generalized additive model of Poisson distribution. We evaluated temporal trends of heat-related mortalities in four periods (1991-1995, 1996-2000, 2001-2005, and 2006-2012). The effects of temperature on mortality were evaluated according to the occurrence of a heat wave and results were compared in the two cities. The effect of temperature on mortality was the greatest in 1991-1995 in Seoul; no significant change was observed in Busan. When we stratified the study period by heat wave status, the risk increase in mortality was 15.9% per 1℃ during years with a heat wave in Seoul, which was much higher than 0.31% increase observed during years without a heat wave. On the other hand, Busan showed a linear relationship between temperature and mortality and no significant difference between years with or without a heat wave. Variations in the relationship between temperature and mortality could be misunderstood if heat waves are not considered. Furthermore, heterogeneity was found in the modifying effect of heat waves on heat-related mortality in inland and coastal cities. The findings of this study help understand relations between temperature and mortality.

No MeSH data available.


Related in: MedlinePlus

Comparison of temperature-mortality relationships in Seoul and Busan by heat wave status.Heat waves in Seoul: 1994, 2012.Heat waves in Busan: 1994, 1996, 2001, 2006, 2012.
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Figure 3: Comparison of temperature-mortality relationships in Seoul and Busan by heat wave status.Heat waves in Seoul: 1994, 2012.Heat waves in Busan: 1994, 1996, 2001, 2006, 2012.

Mentions: The years with a heat wave were 1994 and 2012 in Seoul and 1994, 1996, 2001, 2006, and 2012 in Busan during the study period. Fig. 3 showed relationships between temperature and mortality during years with or without a heat wave in the two cities. During years with a heat wave, the two cities showed quite different mortality responses to temperature. In Seoul, the increases risk of mortality for a 1℃ increase was 15.9% (95%CI: 13.4-18.5) above 29.2℃, and 0.27% below 29.2℃ during years with a heat wave. In contrast, in Busan, temperature had no impact on mortality during years when heat waves occurred (0.04%, 95%CI: -0.21%–0.29%). However, relationships between daily mean temperature and mortality in Seoul and Busan during years without a heat wave differed slightly. The frequency of non-accidental deaths increased by 0.18% (95%CI: -0.09%–0.71%) for a 1℃ increase in Busan, but to 0.34% (95%CI: 0.26%-0.42%) in Seoul.


Modifying Effect of Heat Waves on the Relationship between Temperature and Mortality.

Lee WK, Lee HA, Park H - J. Korean Med. Sci. (2016)

Comparison of temperature-mortality relationships in Seoul and Busan by heat wave status.Heat waves in Seoul: 1994, 2012.Heat waves in Busan: 1994, 1996, 2001, 2006, 2012.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4835594&req=5

Figure 3: Comparison of temperature-mortality relationships in Seoul and Busan by heat wave status.Heat waves in Seoul: 1994, 2012.Heat waves in Busan: 1994, 1996, 2001, 2006, 2012.
Mentions: The years with a heat wave were 1994 and 2012 in Seoul and 1994, 1996, 2001, 2006, and 2012 in Busan during the study period. Fig. 3 showed relationships between temperature and mortality during years with or without a heat wave in the two cities. During years with a heat wave, the two cities showed quite different mortality responses to temperature. In Seoul, the increases risk of mortality for a 1℃ increase was 15.9% (95%CI: 13.4-18.5) above 29.2℃, and 0.27% below 29.2℃ during years with a heat wave. In contrast, in Busan, temperature had no impact on mortality during years when heat waves occurred (0.04%, 95%CI: -0.21%–0.29%). However, relationships between daily mean temperature and mortality in Seoul and Busan during years without a heat wave differed slightly. The frequency of non-accidental deaths increased by 0.18% (95%CI: -0.09%–0.71%) for a 1℃ increase in Busan, but to 0.34% (95%CI: 0.26%-0.42%) in Seoul.

Bottom Line: The effect of temperature on mortality was the greatest in 1991-1995 in Seoul; no significant change was observed in Busan.Furthermore, heterogeneity was found in the modifying effect of heat waves on heat-related mortality in inland and coastal cities.The findings of this study help understand relations between temperature and mortality.

View Article: PubMed Central - PubMed

Affiliation: Department of Social and Preventive Medicine, Inha University School of Medicine, Incheon, Korea .

ABSTRACT
Studies conducted to evaluate temporal trends of heat-related mortality have not considered the effects of heat waves; although it is known they can affect mortality and act as a modifying factor. After adjusting for long-term trends and seasonality, the effects of temperature on non-accidental deaths in Seoul and Busan (inland and coastal cities, respectively) were analyzed using a generalized additive model of Poisson distribution. We evaluated temporal trends of heat-related mortalities in four periods (1991-1995, 1996-2000, 2001-2005, and 2006-2012). The effects of temperature on mortality were evaluated according to the occurrence of a heat wave and results were compared in the two cities. The effect of temperature on mortality was the greatest in 1991-1995 in Seoul; no significant change was observed in Busan. When we stratified the study period by heat wave status, the risk increase in mortality was 15.9% per 1℃ during years with a heat wave in Seoul, which was much higher than 0.31% increase observed during years without a heat wave. On the other hand, Busan showed a linear relationship between temperature and mortality and no significant difference between years with or without a heat wave. Variations in the relationship between temperature and mortality could be misunderstood if heat waves are not considered. Furthermore, heterogeneity was found in the modifying effect of heat waves on heat-related mortality in inland and coastal cities. The findings of this study help understand relations between temperature and mortality.

No MeSH data available.


Related in: MedlinePlus