The Association Between High-Efficiency Particulate Air (HEPA) Filter Usage and Asthma Outcomes in a High Atmospheric Dust Environment: A Cross-Sectional Analysis.

Background and aim  Asthma symptoms are often exacerbated by poor indoor air quality (IAQ). High-efficiency particulate air (HEPA) filters, which remove 99.97% of particles ≥0.3 microns, may mitigate triggers. This study examines associations between HEPA use and asthma control. Methods In a cross-sectional study of 118 asthma patients, HEPA users (n=48) and non-users (n=70; no air purifiers) completed the Asthma Control Test (ACT) and the Asthma Control Questionnaire (ACQ). Outcomes included nighttime/morning symptoms, wheezing, and reliever inhaler use. Results  HEPA users showed non-significant trends toward fewer nighttime symptoms (45.1% vs. 19.7% minimal disturbances, p=0.404) and milder morning symptoms (37.3% vs. 17.0% no symptoms, p=0.120). Long-term users (>one year) reported subjective but non-significant improvements. No differences reached statistical significance (p<0.05). Conclusion While trends suggest potential benefits, HEPA filtration alone did not significantly improve asthma control. Combined IAQ strategies warrant further study.