Objective: To explore the acute health effect of heat wave on cardiovascular emergency department visits ( EDVs ) in Beijing.
Methods: The bidirectional symmetric cases-crossover design was used to analyze the association between heat wave and EDVs for cardiovascular diseases in three hospitals of Beijing from 2009 to 2011.
Results: During the study period, the heat wave occurred five times, including 33 days with high temperature above 35 degrees C and 23 days heat wave. In the bidirectional symmetric cases-crossover design with 1 : 6 matched pairs, the heat wave at the current day has the highest effect on cardiovascular EDVs. The OR values in EDVs for cardiovascular diseases was 1.834 (95% CI 1.767 - 1.922) along with 1 degrees C increase in the maximum temperature. For the hypertension, ischemia heart disease and cerebrovascular disease, the corresponding OR values were 1.912 (95% CI 1.758 - 2.080), 1.770 (95% CI 1.627 - 1.926) and 1.846 (95% CI 1.725 - 1.976), respectively. The people aged 65 years and older were associated slightly stronger with heat wave than the people under the age of 65 years statistically. After being adjusted the other meteorological factors and air pollutants, the significant associations were also found between the heat wave and cardiovascular EDVs, and all adjusted ORs were positively increased.
Conclusion: The acute health effect of heat wave is significantly associated with EDVs for cardiovascular diseases in Beijing.