03/08/2026
The following study was conducted:
"High-Efficiency Particulate Air Filters to Prevent Winter Respiratory Infections in Care Homes"
Concluding:
"In this cluster randomized clinical trial, we found no evidence that HEPA filters reduced resident winter respiratory infection episodes, other infections, antibiotic use, or staff absenteeism."
Interestingly the researchers:
"Considered and decided against conducting monitoring visits to check intervention compliance" - In other words to check the HEPA filters were on.
And stated:
"There were also insufficient CADRs. An explanatory study might have used more sophisticated modeling, including frequency and proximity of staff, visitor, and resident interactions and room ventilation levels to determine more precise CADR requirements. However, we do not believe that a greater number of HEPA filters, or the increased cost, air cooling, and noise associated with higher CADR units, would have been acceptable."
Source:
https://jamanetwork.com/journals/jamainternalmedicine/fullarticle/2852235