The correlation between the outbreaks of asthma attack and meteorologic parameters in Okinawa

Abstract

The correlation between the outbreaks of asthma attack and meterologic parameters was analyzed in Okinawa island which belongs to the subtropics. The epidemiologic outbreaks of asthma was investigated for 2 years from the asthma diaries described by 27 patients. The severity of asthma attack was expressed as the asthma score on the basis of asthma diaries. The number of patients carried to hospitals by ambulance on asthma attacks was investigated for 3 years. Two-by-two contingency tables were computed for the meteorologic parameters and analyzed with the method of chi-square test. From the view point of asthma scores, the total scores of 27 patients were increased when a mean and a minimum temperature were respectively higher than each mean value in the period of investigation (p < 0.05, respectively). From the view point of the number of patients carried to hospitals by ambulance on asthma attacks, it was suggested that asthma attacks tended to occur when a mean, a maximum and a minimum temperature, and a vapor pressure were lower than each mean value (p = 0.0001, p = 0.0001, p = 0.0001, p = 0.0002), and a barometric pressure was higher than a mean value in the period of investigation (p = 0.0016). From the further analysis of these data by multiple regression analysis, it was suggested that the number of patients carried to hospitals by ambulance on asthma attacks was influenced by low temperature. In addition, it was suggested that the changes of meteorologic parameters on the passing over of typhoon, especially, the decrease of temperature and barometric pressure, were related to induce asthma attacks.