ABSTRACT
Objective To estimate the impact of cold wave on daily death of cerebra-cardiovascular diseases in Beijing by using case-crossover design. Methods The data of death counts was provided by Beijing Center for Disease Control and Prevention while the meteorological data was provided by Institute of Urban Meteorology,China Meteorological Administration (CMA),Beijing. The impact of six cold waves from Jan 1,1998 to Jun 30,2000 on daily death of cerebra-cardiovascular diseases were analyzed by using 1∶1 one-directional retrospective design and 1∶2 bi-directional symmetry control design. The cases were the people who dead during winter. Controls were the seventh day before or after the date of cases (or the fourteenth day). Results There were six cold waves in the investigation duration. The third cold wave in which minimum temperature declined obviously with decreasing humidity and increasing air pressure had significantly statistical significance in OR and the lag time of this cold wave was 0 day,the OR values were 1.500 (95%CI:1.032-2.181) for cardiovascular disease (CVD),respectively 1.913 (95%CI:1.066-3.432) for acute myocardial infarction,1.679 (95%CI:1.139-2.474) for cerebra-vascular disease(CBD) respectively. The other five cold waves do not have significant impact on cerebra-cardiovascular diseases. Conclusion Most cold waves studied in Beijing do not impact the daily death counts caused by cerebra-cardiovascular diseases. The cold wave with significant increased air pressure may increase the risk of death of cerebra-cardiovascular diseases without any lag time in Beijing.