Effectiveness of the Air Purification Strategies for the Treatment of Allergic Asthma: A Meta-Analysis

Abstract

We updated the meta-analysis published by McDonald et al. [Chest 2002; 122; 1535-1542 by reviewing the effectiveness of air purification for the treatment of home-related allergic asthma (dust mite, dog, cat, and cockroach). We analysed the trials included by McDonald et al. as well as studies published since 2000. Data on asthma symptoms scores (ASS), medication use, forced expiratory volume in 1 s as a percentage of the predicted value (FEV 1 %pred), histamine provocative concentration causing a 20% reduction in FEV 1 (PC 20 ), Asthma Quality of Life Questionnaire (AQLQ) scores, and fractional exhaled nitric oxide (FeNO) levels were extracted. The effectiveness was examined using metafor (registered in Prospero CRD42019127227). Ten trials including a total of 482 patients (baseline characteristics: mean FEV 1 %pred 83.2%, I 2 = 96.7%; mean PC 20 4.93 mg/mL, I 2 = 44.0%; mean AQLQ 4.67 [max. 7], I 2 = 93.7%; mean FeNO 36.5 ppb, I 2 = 0%) were included. We assessed the mean differences in the AQLQ scores as +0.36 (95% CI 0.10 to 0.62, p = 0.01, n = 302, I 2 = 0%) and the FeNO levels as -6.67 ppb (95% CI -10.56 to -2.77, p = 0.0008, n = 304, I 2 = 0%). The standardised mean differences in all other health outcomes were not significant (ASS -0.68, p = 0.20; medication use: -0.01, p = 0.94; FEV 1 %pred -0.11, p = 0.34; PC 20 +0.24, p = 0.53). We found statistically significant mean differences in the AQLQ scores and FeNO levels in patients with predominantly mild to moderate asthma at baseline. A large trial reported great improvement in the subgroup of patients receiving Global Initiative for Asthma step 4 therapy. We recommend that future studies on air purification focus on patients with severe and poorly controlled allergic asthma.

Effect of nocturnal Temperature-controlled Laminar Airflow on the reduction of severe exacerbations in patients with severe allergic asthma: a meta-analysis

“…Allergen avoidance using air purifications could be an alternative to TLA. However, the effectiveness in asthma treatment by conventional air purification is limited and a recently published meta-analysis by Boven et al [25] showed that the only significant clinical results (AQLQ and FeNO) were demonstrated with TLA. A plausible explanation has been given by Spilak et al [26], who demonstrated that TLA significantly reduces the intrusion of airborne particles into the breathing zone with particle number concentrations being 100-fold lower compared to air-cleaners, which attempt to reduce the allergen/particle load in the whole room, rather than focused in the breathing zone.…”

Effectiveness of Air Filters in Allergic Rhinitis: A Systematic Review and Meta‐Analysis

“…Other studies have included scores for other subdomains such as medication use and asthma into the TSS [17,24], further complicating the assessment of AR symptoms. According to the findings of previous studies and the results of our pooled analyses, the use of air filters may not reduce medication use in patients with allergic respiratory diseases [19,53]. Li et al demonstrated that the presence of asthma does not influence the severity of AR symptoms [46].…”

Development of High-Performance Air Purifier using Human Hair and Vetiver (Chrysopogan Zizanioides) as Filter Media

“…In the next stage, human hair mixed with vegetable oil adsorbs Particulate Matter (PM10) (Van Boven F.E., el al., 2020). This idea was developed by observing the biological system of the human nose where human hairs wetted with mucus fromthe nose prevents the entry of dust and other particulate matters during inhalation of air (Aditya Roy el al.…”