Effects of extreme temperatures on hospital emergency room visits for respiratory diseases in Beijing, China.

Extreme temperature is closely associated with human health, but limited evidence is available for the effects of extreme temperatures on respiratory diseases in China. The goal of this study is to evaluate the effects of extreme temperatures on hospital emergency room (ER) visits for respiratory diseases in Beijing, China. We used a distributed lag non-linear model (DLNM) coupled with a generalized additive model (GAM) to estimate the association between extreme temperatures and hospital ER visits for different age and gender subgroups in Beijing from 2009 to 2012. The results showed that the exposure-response curve between temperature and hospital ER visits was almost W-shaped, with increasing relative risks (RRs) at extremely low temperature. In the whole year period, strong acute hot effects were observed, especially for the elders (age > 65 years). The highest RR associated with the extremely high temperature was 1.36 (95% CI, 0.96-1.92) at lag 0-27. The longer-lasting cold effects were found the strongest at lag 0-27 for children (age ≤ 15 years) and the relative risk was 1.96 (95% CI, 1.70-2.26). We also found that females were more susceptible to extreme temperatures than males.