Asthma Admission Associated with Meteorological Factors in Taiwan

ISEE-0273 Background: The seasonal variation of asthma deserves extensive studies for the association with weather conditions among areas. This study evaluated the risk of hospitalization incidence for asthma associated with weather from 1997 to 2006. Methods: A cohort of 862,842 individuals insured with the National Health Insurance program in Taiwan was identified in 1997. The first hospitalization rates for asthma were measured by month. Relative risks for asthma admissions were estimated in association with information on temperature, barometric pressure, relative humidity, wind speed, accumulated rainfall, and dew point, provided by the Center of Weather Bureau. Results: During the 10-year study period, all the newly admitted asthma cases (N = 12,536) appeared a J-shape association with the diagnosed months. The highest average rate of 16.6 per 100,000 was in March and the lowest rate of 10.2 per 100,000 in August. The multivariate Poisson regression analysis estimated risk for daily asthma incidence revealed a significant inverse association with temperature after controlling for sex, age, year, and other weather variables. Compared with the daily mean temperature of 25–29°C, the relative risk (RR) of the disease increased to 1.23 (95% confidence interval (CI) = 1.04–1.45) when the mean temperature decreased to < 15°C. The risk was also higher when the atmospheric pressure was < 985 hPa (RR = 1.12, 95% CI 1.05–1.19). The risk was also associated with higher humidity. Conclusions: This study demonstrates that the asthma attack risk in Taiwan is elevated when it is colder, with higher atmospheric pressure and higher relative humidity. Key words: asthma, hospital visits, climate change, meteorology, Taiwan.