Abstract: Background　Asthma is a major global health concern，and changes in environmental and meteorological conditions are its important triggers.Objective　To evaluate the effect of environmental comfort in Shijiazhuang on the outpatient volume of asthma in children.Methods　The data of childhood asthma admissions from 2012 to2015 were collected from Children's Hospital of Hebei Province.The average daily temperature（T），relative humidity（RH），wind speed（F） and air pressure（AP） of Shijiazhuang between 2012 and 2015 were provided by Hebei Meteorological Information Center.And data of average daily concentration of PM2.5，SO2 and NO2 were provided by Hebei Provincial Environmental Protection Bureau.The time-series relationship between environmental comfort and daily outpatient volume of childhood asthma was explored by using Poisson Generalized Additive Model（GAM） with Poisson distribution.The smooth spline function was used to control the annual change，seasonal effect and holiday effect，and to eliminate the mixed effects of air pressure，wind speed and air pollutants（PM2.5，SO2 and NO2） on childhood asthma.Compared to comfort level，relative risk（RR） and 95% confidence interval（95%CI） of other hot/cold discomfort levels with childhood asthma admissions were calculated.The Akaike's Information Criterion（AIC） was used to determine the degree of freedom（df） and optimal lag time of the selected factors.Results　A total of 38 429 children afflicted with asthma were selected;Daily average outpatient volume of childhood asthma was（28.2±18.1），and there were more patients in winter but fewer in summer.The average daily temperature varied widely in winter and summer.Air pollution monitoring from 2013 to 2015 showed a higher concentration of PM2.5 in winter，followed by autumn.Compared with comfort, the increased risk of physical cold for asthma in boys, girls and children aged 0-6 ranks first..RR（95%CI） of extremely hot discomfort on the volume of childhood asthma was 1.01（0.91，1.12），but other thermal discomfort didn't increase the risk.The effect of cold discomfort on the volume of childhood asthma admissions was the largest in the 3-day-lag.The effect of hot discomfort on the outpatient volume of childhood asthma was the strongest in the lag of 3 days.Conclusion　Comfort level has an effect on the daily outpatient volume of childhood asthma，while the main effects was caused by cold discomfort，followed by thermal discomfort.According to the comfort level forecast given by meteorological department，people can take measures to prevent childhood asthma.

Key words: Asthma, Environment and public health, Child, Time series, Ambulatory care

摘要： 背景　支气管哮喘（简称哮喘）是一个全球性的主要健康问题，环境气象条件变化是其重要触发因素。目的　评价石家庄环境舒适度对儿童哮喘日门诊量的影响。方法　收集2012—2015年河北省儿童医院儿童哮喘门诊的患儿资料，2012—2015年石家庄的日平均气温（T）、相对湿度（RH）、风速（F）、气压（AP）、降水（R）由河北省气象信息中心提供，2013—2015年PM2.5、二氧化硫（SO2）、二氧化氮（NO2）日均浓度资料由河北省环保局提供。通过泊松分布的广义相加模型（GAM）分析环境舒适度与儿童哮喘日门诊人数的时间序列关系。采用平滑样条函数控制年变化、季节效应、节假日效应，消除F、AP和大气污染物PM2.5、SO2、NO2浓度对儿童哮喘的混杂影响，计算相对于舒适等级，其他冷热不舒适等级对儿童哮喘门诊人数的相对危险度（RR）及95%可信区间（95%CI）。根据赤池信息量（AIC）最小准则，确定入选各因子的自由度（df）及最佳滞后时间。结果　入选哮喘患儿38 429人次；儿童哮喘日均门诊人数（28.2±18.1）人次，冬季较多，夏季较少；冬夏气温相差悬殊；2013—2015年大气污染监测显示冬季PM2.5浓度较高，其次是秋季。相对于舒适，体感寒冷对男、女、0~6岁儿童哮喘门诊人数增加的风险均居于第一位。极热不舒适对儿童哮喘门诊人数增加的RR（95%CI）为1.01（0.91，1.12），其他热不舒适未发现风险增加。冷不舒适对儿童哮喘门诊人数影响在滞后3 d效应值最大。热不舒适对儿童哮喘门诊人数影响在滞后3 d效应值最大。结论　舒适度等级对儿童哮喘日门诊人数有影响，以冷不舒适等级效应为主，热不舒适等级效应为辅，根据气象部门舒适度预报，可对儿童哮喘的防御提供帮助。

关键词: 哮喘, 环境和公共卫生, 儿童, 时间序列, 门诊医疗