[Time-series analysis on the relationship between ambient PM2.5 and daily outpatient visits due to allergic conjunctivitis among children in Shenzhen].

Objective: To explore the short-term effects of ambient PM2.5 on the outpatient visits of allergic conjunctivitis among children in Shenzhen. Methods: It was a ecological study. Data on daily visits including date of visit, sex and age from children with allergic conjunctivitis were collected from Shenzhen Eye Hospital and Shenzhen Children's Hospital in 2018. Related data on air pollution (PM2.5, PM10, SO2, NO2, CO and O3) and meteorology (atmospheric pressure, temperature and relative humidity) were also collected. Pearson correlation analysis was used for normal distribution data and Spearman rank correlation analysis was used for non-normal distribution data. Generalized additive model was used to estimate the impact of PM2.5 pollution on allergic conjunctivitis outpatients and the lagging effects. Results: In 2018, there were 16 133 allergic conjunctivitis outpatients in the two hospitals. The maximum age was 18 years and the minimum age was 2 months. Males accounted for 49.3%. The daily average concentration of PM2.5 was 22 (15, 31) μg/m3. Changes of the concentration of PM2.5 had a positive correlation with the amount of allergic conjunctivitis visits, and the Spearman correlation coefficient was 0.150 (P=0.004). The single pollutant model showed that the strongest effect appeared at 3 days (RR=1.111， 95%CI:1.071-1.152). A 10 μg/m3 increase of PM2.5 would result in an excessive number of allergic conjunctivitis outpatients as much as 11.112% (95%CI：7.011%-15.212%). In the multiple air pollutants models, after the introduction of NO2, O3 and CO, the concentration of PM2.5 showed an enhanced effect on the number of hospital visits due to allergic conjunctivitis on the same day, and the difference was statistically significant (P<0.05). Conclusion: Changes of the concentration of PM2.5 had a positive correlation with daily outpatient visits of allergic conjunctivitis among children in Shenzhen. (Chin J Ophthalmol, 2020, 56: 608-614).目的： 探讨深圳地区大气细颗粒物（PM2.5）浓度对儿童过敏性结膜炎门诊量的短期影响。 方法： 生态学研究。收集深圳市眼科医院和深圳市儿童医院2018年儿童过敏性结膜炎逐日就诊资料（包括就诊日期、性别、年龄等）及同期大气污染物（PM2.5、可吸入颗粒物、SO2、NO2、CO和O3）及气象（气压、气温和相对湿度）数据。正态分布数据采用Pearson相关分析变量间相关关系，非正态数据采用Spearman秩相关分析；使用广义相加模型分析大气PM2.5浓度与儿童过敏性结膜炎门诊量的关系及滞后效应。 结果： 纳入的过敏性结膜炎儿童16 133人次，年龄2个月至18岁，男性和女性占比分别为49.3%和50.7%。2018年深圳市日均大气PM2.5浓度为22（15，31）μg/m3。大气PM2.5浓度与过敏性结膜炎就诊量的相关系数为0.150（P=0.004）。单污染物模型显示，大气PM2.5浓度对过敏性结膜炎门诊量在滞后第3天效应最强（相对危险度为1.111，95%可信区间为1.071~1.152），大气PM2.5浓度每增加10 μg/m3，儿童过敏性结膜炎门诊量增加11.112%（95%可信区间为7.011%~15.212%）。多污染物模型显示，引入NO2、O3、CO后，大气PM2.5浓度对过敏性结膜炎就诊效应强度有所增强，差异均有统计学意义（P<0.05）。 结论： 深圳地区大气PM2.5浓度与儿童过敏性结膜炎就诊量呈正相关。（中华眼科杂志，2020，56：608-614）.