ABSTRACT
Objective To investigate the influence of meteorological factors on the number of patients and the time patients visiting the emergency department for medical care.Methods The data of meteorological variation and air pollution associated with the characteristics of distribution of time when the patients visited the emergency department in a tertiary grade A class hospital in Shanghai were collected in 2016.Quasi Poisson generalized additive model (GAM) applied for time series analysis was used to find the correlation between daily temperature and number of patients visiting emergency department,and with the distributed lag nonlinear model (DLNM) the relationship between the temperature and humidity was established and the confounding factors related with time visiting the emergency department was controlled in this model.Results In 2016,the average number of emergency visits in a tertiary grade A class hospital in Shanghai was 1027.The peak flow of patients occurred between 18:00 to-22:00 and trough emerged between 2:00 to-8:00.The number of visits in winter was greater than that in spring and autumn,and the number of patients on weekends and holidays was more than that on weekdays.The response of temperature exposure to the change of emergency volume in the hospital showed a J shape distribution.The low temperature and high temperature caused increase in visits,and the low temperature effect could last more than 2 weeks.The lowest number of visits occurred when the temperature (that is the lowest suitable temperature for medical treatment) was about 7 degrees Celsius,and the daily number of patients in emergency internal medicine was increased to 1.09 times (95％CI:1.03～1.16) compared with the optimum temperature.Compared with the optimum temperature,the daily visits increased to 1.27 times (95％CI:1.08～1.50) in the highest temperature.When the suitable temperature decreased by 1 degree,the visiting quantity increased by 2.43％ (95％CI:0.83％～4.18％),and the number of visits increased by 0.96％ (95％CI:0.31％～1.64％) every 1 degree rise.Conclusions There was a difference in the number of emergency visits between different times,and low temperature and high temperature had an obvious influence on the amount of emergency visits,and the effect of low temperature on the volume of visits was more lasting.
ABSTRACT
BACKGROUND AND PURPOSE: There is conflicting evidence for whether or not the incidence of stroke is influenced by the daily temperature. The association between daily temperature and incidence of stroke is largely unknown in Korea. This study attempted to evaluate whether the maximum or minimum daily temperature is associated with increased numbers of strokes and stroke subtypes among Seoul residents. METHODS: We obtained the maximum and minimum daily temperatures in Seoul from the Korean Meteorological Administration between January 2005 and December 2014. Consecutive patients with acute stroke were registered who visited the emergency room or outpatient clinic in Soonchunhyang University Hospital, Seoul. The residential addresses of cases were restricted to within a 2-kilometer radius of this hospital. The stroke events were prospectively recorded with onset time, and were classified by subtypes. The categories of daily temperature were divided by 10℃ from the mean temperature. The mean daily number of strokes was calculated during the study period. One-way analysis of variance and Duncan's post-hoc test were applied to compare the number of strokes among the temperature groups. RESULTS: In total, 2,313 acute strokes were identified during the period: 1,643 ischemic strokes and 670 hemorrhagic strokes. The number of cases was significantly higher when the maximum daily temperature was >32℃ or ≤3℃ (p=0.048) or the minimum daily temperature was ≤-11.0℃ (p=0.020). The lowest maximum daily temperature was associated with increased instances of intracerebral hemorrhage (p=0.029) and small-vessel occlusion (p=0.013), while the highest maximum daily temperature was associated with an increased instance of large-artery atherosclerosis (p=0.045). CONCLUSIONS: The daily temperature had measurable and different associations with the number of strokes and strokes subtypes in Seoul, Korea.