[The impact of air temperature variation on the visits to emergency room in Shanghai].
OBJECTIVE
To assess the association between air temperature and emergency room visits among patients covered by medical care program from 'third-grade' hospitals in Shanghai.


METHODS
Generalized additive model (GAM) was used to analyze time series, and AR(P) was used to deal with auto correlation of time series. After controlling factors as both medium-term and long-term trends, day of the week, vocation, typical pneumonia and pollutants, the association between air temperature and emergency room visits in virtue of quadratic curve and differential coefficient principle were estimated.


RESULTS
When air temperature was below 14.71 degrees C, the increase of 95% confidence interval to relative risk in corresponding emergency room visits along with 1 degree C increase of air temperature, was less than 1. However, when air temperature was above 19.59 degrees C, the relative risk's 95% confidence interval was greater than 1. When air temperature varied at the range of 14.71 degrees C-19.59 degrees C, the 95% confidence interval of the relative risk would include 1. Hence, air temperature range between 14.71 degrees C-19.59 degrees C, was called the optimum temperature range.


CONCLUSIONS
Our findings indicated that the current air temperature had an acute impact on the number of emergency room visits among patients covered by medical care program visiting those third grade hospitals in Shanghai.
Dong
Ying
Y
Department of Preventive Medicine, Shanghai Traditional Chinese Medicine University, Shanghai 201203, China.
Zhao
Nai-Qing
NQ
Wang
Ai-Rong
AR
Jia
Guang-Yi
GY
D002681:China; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data*; D006801:Humans; D015233:Models, Statistical; D010045:Outpatients / Q000706:statistics & numerical data*; D013696:Temperature