The rescue intervention strategy for asthma patients under severe air pollution: a single-center prospective randomized controlled trial

The aim of our study is to provide a novel strategy to administer treatment at the first signs of severe air pollution and before patients experience symptoms for preventing airway damage.
This single-center, prospective, randomized and standard treatment parallel control clinical trial recruited adult asthma patients. The patients were randomized into either the rescue intervention strategy (RIS) group or control group. The rescue intervention strategy for the RIS group included budesonide/formoterol plus the original treatment until the severe pollution ended. The control group was maintained on the original treatment. The follow-up observation period was 1 year.
Overall, 22 participants were enrolled and 20 completed the follow-up (11 in the RIS group and 9 in the control group). Two participants dropped out of the trial for personal reasons before the first follow-up. In the intention-to-treat analysis, the frequency of asthma exacerbations per year was significantly lower in the RIS group than in the control group (RIS vs. control, 0.55 vs. 2.67; risk rate [RR] [95% confidence interval {CI}], 0.21 [0.08-0.50]; p = 0.001). The mean number of unplanned outpatient visits per person per year was also lower in the RIS group than in the control group (RIS vs. control, 0.18 vs. 1.11; RR [95% CI], 0.16 [0.04-0.75]; p = 0.019).
A novel strategy to administer treatment at the first signs of severe air pollution and before patients experience symptoms may decrease the risk of asthma exacerbations and negative outcomes under severe air pollution conditions.
ChiCTR, ChiCTR1900026757. http://www.chictr.org.cn.

本研究旨在提出一种全新的干预策略，即在重度空气污染首次显现时、患者出现相关症状前即启动治疗，以预防气道损伤。
本研究为单中心、前瞻性、随机、标准治疗平行对照临床试验，招募成年哮喘患者。受试者被随机分配至救援干预策略（rescue intervention strategy, RIS）组与对照组。RIS组采用布地奈德/福莫特罗联合原治疗方案的救援干预策略，直至重度污染结束；对照组仅维持原治疗方案。随访观察周期为1年。
本试验共纳入22名受试者，其中20名完成随访（RIS组11名，对照组9名）。2名受试者因个人原因在首次随访前退出试验。意向性治疗分析（intention-to-treat analysis）显示，RIS组每年哮喘急性发作频率显著低于对照组（RIS组vs对照组：0.55 vs 2.67；风险比（risk rate, RR）[95%置信区间（confidence interval, CI）]：0.21 [0.08-0.50]；p=0.001）。RIS组人均每年非计划性门诊就诊次数亦低于对照组（RIS组vs对照组：0.18 vs 1.11；RR [95% CI]：0.16 [0.04-0.75]；p=0.019）。
本研究提出的在重度空气污染首次出现、患者出现症状前启动治疗的全新策略，可降低重度空气污染环境下哮喘急性发作及不良预后的风险。
本试验注册于中国临床试验注册中心（Chinese Clinical Trial Registry, ChiCTR），注册号为ChiCTR1900026757，网址为http://www.chictr.org.cn。