A Study on the Association between Ambient Daily Average Temperature and Daily Mortality of Circulatory System Diseases in Shenyang City,1992-2000 / 中国慢性病预防与控制

ABSTRACT

Objective To assess the association between air pollution and daily mortality of circulatory system diseases.Methods All death records of the deceased who lived in urban area of Shenyang and died from circulatory system disease during Jan 1,1992 to Dec 31,2000 were collected.We used the semi-parametric generalized additive model to study the relationship between short-term daily average temperature and daily mortality of circulatory system diseases after controlling the confounding factors of long-term trends,humidity,air pressure,work days and season,etc.Results The optimal temperature for all people was 23.4℃.And it was 23.6℃ for male and 23.2℃ for female.A significant graphically 'V' shape relationship between mortality caused by circulatory diseases and ambient temperature was found.The relationship between the temperature changes and the mortality caused by cardiovascular diseases was significant,but not significant with cerebrovascular diseases.The mortality caused by cardiovascular diseases increased 0.0275/100 000 while the temperature increasing each 1℃ above 23.4℃,and increased 0.0062/100 000 while temperature decreasing each 1℃ below 23.4℃.People over 65 years old were the most sensitive population for temperature changing,their mortality caused by cardiovascular diseases increased 1.1909/100 000 when the temperature increasing each 1℃ from 26.6℃.But people under 65 years old were not sensitive to temperature changing,their mortality caused by cardiovascular diseases was all less than 0.0011/100 000 no matter the temperature was higher or lower 1℃ from the optimal temperature.There was no significant difference of the effect of temperature changing on mortality caused by cardiovascular between male and female.Conclusion The "V" shape relationship between mortality caused by cardiovascular diseases and ambient temperature clues us on that temperature left from the optimal temperature could increase the death rate caused by cardiovascular diseases and temperature closed to the optimal temperature could decrease the death rate caused by cardiovascular diseases.