Short-term Effects Of Heat Wave And Cold Spell On Admission Of Children With Allergic Rhinitis In Hefei Area

Background: In recent years,due to change of global climate,especially the frequent occurrence of extreme weather,the impact of extreme temperature events on respiratory diseases has drawn increasing attention.As an allergic respiratory disease,allergic rhinitis is more susceptible to extreme temperature events.Previous studies have found that high and low temperature are associated with admission to children with allergic rhinitis,and studies on the association between extreme temperature events and children with allergic rhinitis are scarced.Objectives:(1)By fitting different definitions of heat waves and cold spells to the admission of children with allergic rhinitis,to find out the optimal definition of heat wave and cold spell in Hefei,and provide an important reference for disease warning;(2)Quantitatively assessing the short-term effects of heat wave and cold spell on the admission of children with allergic rhinitis,and further identifying potential susceptible populations.Methods: This study collected admission information of patients with allergic rhinitis aged 0-14 years of Anhui Children’s Hospital from January 1,2014 to December 31,2016,including: admission date,age,gender,residential address,Parenting form,disease diagnosis,etc.At the same time,the meteorological data from the Hefei Meteorological Bureau and the air pollutants from the Hefei Environmental Protection Bureau were collected.Poisson’s generalized linear regression model combined with distributed lag nonlinear model was used to investigate the effects of heat wave and cold spell on the admission of children with allergic rhinitis,while controlling the potential confounding effects of relative humidity,air pollutants,seasonality,long-term trends of time,holidays and DOW.Results:(1)Except that defined as the daily average temperature is greater than the 97 th percentile score and the duration is greater than or equal to three days,the other three definitions of heat wave show that the heat wave has a statistically significant effect on the admission of children with allergic rhinitis,and it have hysteresis effect and the trend is similar.Under the optimal definition of heat wave,compared with non-heat wave periods,heat wave can significantly increase the admission of children with allergic rhinitis,and in a certain,there is hysteresis effect,which is from the lag 2 day to the lag 4 day,and the maximum lag effect is 1.051(95%CI: 1.022-1.081)at the lag 3 day,the cumulative effect is 1.101(95%CI: 1.001-1.211),which only occurs at the lag 0-4 days.(2)Under the different definition of cold spells,the cold spell has a certain impact on the admission of children with allergic rhinitis,and the trend of its lag effect is similar.Under the optimal definition of cold spell,compared with non-cold spell periods,the cold spell has a significant effect on the admission of children with allergic rhinitis,and in a certain,there is hysteresis effect.The effect is 1.116(95%CI: 1.053-1.182)on the lag0,and then gradually decreasing,the cumulative effect appeared from lag 0-1 days,then gradually increased to 1.308(95%CI: 1.089-1.571)at lag 0-8 days.(3)subgroup analysis of gender,age,and parenting patterns showed that male children,children aged 5-14 years,and non-scattered children were susceptible to allergic rhinitis on heat wave and cold spell days.Conclusion:(1)Heat wave and cold spell can significantly increase the admission of allergic rhinitis in children’s outpatient clinic,and it has short-term acute hysteresis effect,and the effect caused by cold spell is more larger than heat wave;(2)During the heat wave and cold wave periods,the susceptible population of allergic rhinitis are male children,children aged 5-14 years and non-scattered children;(3)The optimal heat wave in the region is defined as the daily average temperature is greater than the 97 th percentile of the average temperature and the duration is greater than or equal to two days.The optimal cold spell is defined as the daily average temperature below the 10 th percentile of the average temperature and the duration is greater than or equal to two days,which will provide an important reference for early warning of disease in the region.