Methods: 

• This was a blinded randomized controlled trial.
• The study enrolled former smokers with moderate-severe COPD to receive active or sham portable HEPA air cleaners.
• The subjects were followed for 6 months.
• Primary outcome was 6-month change in Saint George’s Respiratory Questionnaire (SGRQ)
• Secondary outcomes included:

    Risk of exacerbation 

    Respiratory symptoms 

    Use of rescue medication 

    6MWD(minute walk distance) 

Results

Conclusions: 

This study showed potential health benefits of portable HEPA air cleaners, especially in people with greater adherence and those spending a greater time indoors. 

Reference-

Hansel NN, Putcha N, Woo H, et al. Randomized Clinical Trial of Air Cleaners to Improve Indoor Air Quality and COPD Health: Results of the CLEAN AIR STUDY. Am J Respir Crit Care Med. 2021 Aug 27.

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