HEPA filters provide no additional protection against respiratory infections

Using high-efficiency particulate air (HEPA) filters on top of existing infection-prevention measures in care homes does little to further reduce respiratory and other infections, as shown in a study.

The study was conducted in the UK across 91 care homes. These homes were randomly assigned to receive HEPA filters (intervention, n=47) or continue with usual infection, prevention, and control measures (control, n=44). Care homes assigned to the intervention received up to five HEPA filters for communal areas (clean air delivery rate set at 160 m³/h) and up to 16 filters for bedrooms (clean air delivery rate set at 60 m³/h). This group continued usual infection prevention and control measures.

The primary outcome was respiratory infection rate per winter per bedroom resident (exposed to bedroom and communal room filters). Staff absenteeism was also assessed as a secondary outcome.

Care homes in the intervention group had 569 residents (median age 87 years, 70 percent female), while care homes in the control group had 589 residents (median age 88 years, 71.8 percent female). The number of respiratory infections per winter was similar in the intervention and the control groups (0.99 vs 1.04; adjusted incident rate ratio [IRR], 0.92, 95 percent confidence interval [CI], 0.64–1.33; p=0.67).

Staff absenteeism rates were also comparable between the two groups (adjusted IRR, 0.80, 95 percent CI, 0.55–1.16; p=0.24).

These findings indicate that existing prevention measures to control respiratory and other infections in care homes are sufficient.