HEPA Filter Trial in Nursing Homes Shows No Benefit

What happened

A cluster randomized trial of HEPA filters in nursing homes found no significant difference in respiratory infections per winter between intervention and control residents (0.99 vs 1.04; adjusted incident rate ratio, 0.92; 95% CI, 0.64-1.33; P = .67).

Why it matters

This negative result challenges the widespread calls to spend hundreds of millions on HEPA filters in schools and homes, and highlights that expert claims should be questioned and tested in randomized trials.