A clinical colleague says “never order a test that you can’t, or won’t, act upon.” This is important in the discussion of POC and RDT assays. I believe in both the patient & public health level value of these assays, but only if we invest in the systems to act upon the results 1/

At home tests that tell someone they should quarantine, without a system that allows them to stay home without fear of food/shelter/income insecurity, are of little value. 2/

At home tests that are too expensive, inaccessible, or poorly marketed to achieve broad and equitable uptake, are of little value 3/

POC tests that trade-off speed for sensitivity and specificity can be of great value in some settings (e.g. rapid cluster detection) but easily misinterpreted as true negatives, leading to false confidence 4/

A surveillance system that doesn’t distinguish between the tests being used and the criteria for use (e.g. symptomatic uses test A, contacts use test B, routine screening uses test C, etc) can lead to impossibly confounded numbers 5/

As I’ve said before. Things will not save us. I want us to develop great things, things will help, systems are what we need to ensure that they can. fin