Variable uptake of face masks could reinforce health inequalities

Greenhalgh and colleagues present a pragmatic argument for face mask use by the public in response to covid-19.1 Their precautionary principle model in the absence of clear evidence invokes the parachute approach to evidence based medicine.2 To extend that analogy, although trialling parachutes seems redundant, considerations such as quality control, “user” training, and ultimately reach remain relevant. Before implementing guidance from the US Centers for Disease Control …