PDF(Pubmed)
Abstract：
Triple-crossover randomized controlled intervention trial to test whether reduced exposure to household NO2 or fine particles results in reduced symptoms among children with persistent asthma.
Children (n = 126) aged 5-11 years with persistent asthma living in homes with gas stoves and levels of NO2 15 ppb or greater recruited in Connecticut and Massachusetts (2015-2019) participated in an intervention involving three air cleaners configured for: (1) NO2 reduction: sham particle filtration and real NO2 scrubbing; (2) particle filtration: HEPA filter and sham NO2 scrubbing; (3) control: sham particle filtration and sham NO2 scrubbing. Air cleaners were randomly assigned for 5-week treatment periods using a three-arm crossover design. Outcome was number of asthma symptom-days during final 14 days of treatment. Treatment effects were assessed using repeated measures, linear mixed models.
Measured NO2 was lower (by 4 ppb, p < .0001) for NO2-reducing compared to control or particle-reducing treatments. NO2-reducing treatment did not reduce asthma morbidity compared to control. In analysis controlling for measured NO2, there were 1.8 (95% CI -0.3 to 3.9, p = .10) fewer symptom days out of 14 in the particle-reducing treatment compared to control.
It remains unknown if using an air cleaner alone can achieve levels of NO2 reduction large enough to observe reductions in asthma symptoms. We observed that in small, urban homes with gas stoves, modest reductions in asthma symptoms occurred using air cleaners that remove fine particles. An intervention targeting exposures to both NO2 and fine particles is complicated and further research is warranted.
NCT02258893.
Children (n = 126) aged 5-11 years with persistent asthma living in homes with gas stoves and levels of NO2 15 ppb or greater recruited in Connecticut and Massachusetts (2015-2019) participated in an intervention involving three air cleaners configured for: (1) NO2 reduction: sham particle filtration and real NO2 scrubbing; (2) particle filtration: HEPA filter and sham NO2 scrubbing; (3) control: sham particle filtration and sham NO2 scrubbing. Air cleaners were randomly assigned for 5-week treatment periods using a three-arm crossover design. Outcome was number of asthma symptom-days during final 14 days of treatment. Treatment effects were assessed using repeated measures, linear mixed models.
Measured NO2 was lower (by 4 ppb, p < .0001) for NO2-reducing compared to control or particle-reducing treatments. NO2-reducing treatment did not reduce asthma morbidity compared to control. In analysis controlling for measured NO2, there were 1.8 (95% CI -0.3 to 3.9, p = .10) fewer symptom days out of 14 in the particle-reducing treatment compared to control.
It remains unknown if using an air cleaner alone can achieve levels of NO2 reduction large enough to observe reductions in asthma symptoms. We observed that in small, urban homes with gas stoves, modest reductions in asthma symptoms occurred using air cleaners that remove fine particles. An intervention targeting exposures to both NO2 and fine particles is complicated and further research is warranted.
NCT02258893.
摘要：
■三重交叉随机对照干预试验，以测试减少家庭NO2或细颗粒暴露是否会导致持续性哮喘儿童症状减轻。
■在康涅狄格州和马萨诸塞州（2015-2019年）招募的5-11岁患有持续性哮喘的儿童（n=126）居住在有燃气灶的家庭中，NO2含量为15ppb或更高（2015-2019年）参与了一项干预措施，涉及三种空气净化器，这些空气净化器配置为：（1）减少NO2：假颗粒过滤和真正的NO2洗涤；（2）颗粒使用三臂交叉设计将空气净化器随机分配5周的治疗期。结果是在治疗的最后14天期间的哮喘症状天数。使用重复措施评估治疗效果，线性混合模型。
■测得的NO2较低（降低4ppb，p<.0001)对于NO2还原与对照或颗粒还原处理相比。与对照组相比，减少NO2的治疗并未降低哮喘的发病率。在对测量的NO2进行控制的分析中,与对照相比,在颗粒减少治疗中14个中有1.8(95%CI-0.3至3.9,p=.10)更少的症状天数。
■单独使用空气净化器是否可以达到足够大的NO2减少水平以观察哮喘症状的减少，目前尚不清楚。我们观察到，在小的，有燃气灶的城市家庭，使用去除细颗粒的空气净化器可适度减轻哮喘症状。针对NO2和细颗粒暴露的干预措施很复杂，需要进一步研究。
■NCT02258893。
■在康涅狄格州和马萨诸塞州（2015-2019年）招募的5-11岁患有持续性哮喘的儿童（n=126）居住在有燃气灶的家庭中，NO2含量为15ppb或更高（2015-2019年）参与了一项干预措施，涉及三种空气净化器，这些空气净化器配置为：（1）减少NO2：假颗粒过滤和真正的NO2洗涤；（2）颗粒使用三臂交叉设计将空气净化器随机分配5周的治疗期。结果是在治疗的最后14天期间的哮喘症状天数。使用重复措施评估治疗效果，线性混合模型。
■测得的NO2较低（降低4ppb，p<.0001)对于NO2还原与对照或颗粒还原处理相比。与对照组相比，减少NO2的治疗并未降低哮喘的发病率。在对测量的NO2进行控制的分析中,与对照相比,在颗粒减少治疗中14个中有1.8(95%CI-0.3至3.9,p=.10)更少的症状天数。
■单独使用空气净化器是否可以达到足够大的NO2减少水平以观察哮喘症状的减少，目前尚不清楚。我们观察到，在小的，有燃气灶的城市家庭，使用去除细颗粒的空气净化器可适度减轻哮喘症状。针对NO2和细颗粒暴露的干预措施很复杂，需要进一步研究。
■NCT02258893。
