目的: 分析不同季节不同度量方式的臭氧(ozone, O₃)浓度对儿童哮喘门诊就诊人次的影响,探讨该影响在不同类型人群中的差异。方法: 收集兰州市三所三级甲等综合医院2014年1月1日至2017年12月31日儿童哮喘门诊的就诊资料,收集同期空气污染数据和气象数据,考虑到O₃浓度与儿童哮喘门诊就诊人次及气象因素之间的非线性关系,利用广义相加时间序列模型分析O₃浓度变化与儿童哮喘门诊就诊人次的短期关联性,同时进一步对性别、年龄进行分层分析,考虑到O₃在1 d内浓度变化情况,同时采用每日1 h最大值浓度(O₃max1h)、每日8 h最大值浓度(O₃8h)以及每日24 h均值浓度(O₃24h)这三种O₃暴露的不同度量方式作为O₃短期暴露指标,并分别开展模型分析。结果: 夏季时,O₃短期暴露水平的升高对于儿童哮喘门诊就诊人次的增加有显著影响。在滞后当天(lag0)的情况下,大气O₃max1h浓度每增加10 μg/m³,儿童哮喘门诊就诊人次增加3.351% (95%CI:1.231%~5.516%);O₃8h浓度每增加10 μg/m³,儿童哮喘门诊就诊人次增加3.320% (95%CI:0.197%~3.829%);O₃24h浓度每增加10 μg/m³,夏季儿童哮喘门诊就诊人次增加6.600% (95%CI:0.914%~12.607%);此外,O₃max1h暴露增加也会引起0~5岁儿童及男性哮喘门诊就诊人次的显著增加。结论: 兰州市夏季时O₃短期暴露水平的升高对于儿童哮喘门诊就诊风险的增加有显著影响,O₃max1h与儿童哮喘门诊就诊人次增加的关联更密切。

Objective: To analyze the effects of ozone (O₃) concentrations measured with different approaches across different seasons on the total number of childhood asthma-related clinical visits, as well as the differentiation of such effects across different groups of patients. Methods: The outpatient data of three grade A tertiary hospitals in Lanzhou City spanning from 1 January 2014 to 31 December 2017, as well as air pollution and meteorological data during the same period were collected. Considering the nonlinear relationship between O₃ concentrations and the total number of childhood asthma-related clinical visits and meteorological factors, a generalized additive temporal sequence model was employed to analyze the short-term association between changes in O₃ concentrations and the total number of childhood asthma-related clinical visits. Taking into account of the variations in O₃ concentrations within 1 day, this study adopted different measurement approaches to address the three types of O₃ exposures, namely, the maximum 1 h daily concentration (O₃max1h), the maximum 8 h daily concentration (O₃8h) and the mean 24 h daily concentration (O₃24h) as the short term exposure indicators to O₃, followed by a model-based analysis. Results: The increase in short-term exposure levels to O₃ in summer had a significant effect on the increase in the total number of childhood asthma-related clinical visits. With lag0 for the current day, every 10 μg/m³ increase in atmospheric concentration of O₃max1h was associated with an increase in the total number of childhood asthma-related clinical visits by 3.351% (95%CI: 1.231%-5.516%); for every 10 μg/m³ increase in O₃8h concentration, the total number of childhood asthma-related clinical visits increased by 3.320% (95%CI: 0.197%-3.829%); for every 10 μg/m³increase in O₃24h concentration, the total number of childhood asthma-related clinical visits in summer increased by 6.600% (95%CI: 0.914%-12.607%); moreover, an increase in exposure to O₃max1h also led to a significant rise in the total number of childhood asthma-related clinical visits among the males. Conclusion: The increase in short-term exposure levels to O₃ in summer in Lanzhou City has a significant effect on the increase in the total number of childhood asthma-related clinical visits; O₃max1h is more closely correlated with the increase in the total number of childhood asthma-related clinical visits.