Orellano Pablo, Quaranta Nancy, Reynoso Julieta, Balbi Brenda, Vasquez Julia
Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina.
Universidad Tecnológica Nacional, Facultad Regional San Nicolás, San Nicolás, Argentina.
PLoS One. 2017 Mar 20;12(3):e0174050. doi: 10.1371/journal.pone.0174050. eCollection 2017.
Several observational studies have suggested that outdoor air pollution may induce or aggravate asthma. However, epidemiological results are inconclusive due to the presence of numerous moderators which influence this association. The goal of this study was to assess the relationship between outdoor air pollutants and moderate or severe asthma exacerbations in children and adults through a systematic review and multilevel meta-analysis.
We searched studies published in English on PubMed, Scopus, and Google Scholar between January 2000 and October 2016. Studies following a case-crossover design with records of emergency departments and/or hospital admissions as a surrogate of moderate or severe asthma exacerbations were selected. A multilevel meta-analysis was employed, taking into account the potential clustering effects within studies examining more than one lag. Odds ratios (ORs) and 95% confidence intervals were estimated. A subgroup analysis in children aged 0 to 18 years and a sensitivity analysis based on the quality of the included studies as defined in the Newcastle-Ottawa Scale were performed. Publication bias was evaluated through visual inspection of funnel plots and by a complementary search of grey literature. (Prospero Registration number CRD42015032323).
Database searches retrieved 208 records, and finally 22 studies were selected for quantitative analysis. All pollutants except SO2 and PM10 showed a significant association with asthma exacerbations (NO2: 1.024; 95% CI: 1.005,1.043, SO2: 1.039; 95% CI: 0.988,1.094), PM10: 1.024; 95% CI: 0.995,1.053, PM2.5: 1.028; 95% CI: 1.009,1.047, CO: 1.045; 95% CI: 1.005,1.086, O3: 1.032; 95% CI: 1.005,1.060. In children, the association was significant for NO2, SO2 and PM2.5.
This meta-analysis provides evidence of the association between selected air pollutants and asthma exacerbations for different lags.
多项观察性研究表明，室外空气污染可能诱发或加重哮喘。然而，由于存在众多影响这种关联的调节因素，流行病学结果尚无定论。本研究的目的是通过系统评价和多水平荟萃分析，评估室外空气污染物与儿童及成人中重度哮喘发作之间的关系。
我们检索了2000年1月至2016年10月期间在PubMed、Scopus和谷歌学术上发表的英文研究。选择采用病例交叉设计且以急诊科记录和/或住院人数作为中重度哮喘发作替代指标的研究。采用多水平荟萃分析，考虑在研究多个滞后时间时潜在的聚类效应。估计比值比（OR）和95%置信区间。对0至18岁儿童进行亚组分析，并根据纽卡斯尔-渥太华量表定义的纳入研究质量进行敏感性分析。通过漏斗图的可视化检查和对灰色文献的补充检索来评估发表偏倚。（国际前瞻性系统评价注册库注册号CRD42015032323）。
数据库检索得到208条记录，最终选择22项研究进行定量分析。除二氧化硫和PM10外，所有污染物均与哮喘发作有显著关联（二氧化氮：1.024；95%置信区间：1.005,1.043，二氧化硫：1.039；95%置信区间：0.988,1.094），PM10：1.024；95%置信区间：0.995,1.053，PM2.5：1.028；95%置信区间：1.009,1.047，一氧化碳：1.045；95%置信区间：1.005,1.086，臭氧：1.032；95%置信区间：1.005,1.060。在儿童中，二氧化氮、二氧化硫和PM2.5的关联显著。
这项荟萃分析为不同滞后时间下选定空气污染物与哮喘发作之间的关联提供了证据。
