Chicken Or Egg?

Assessing the influence of mass viral testing programmes on case positivity: are we experiencing a testdemic? (rev 1.0)

This morning my first thoughts upon waking were, “shall I try vector autoregression (VAR) or vector error correction modelling (VECM)?” Yes, really.

Whenever I start to tread down the path of ever more sophisticated statistical techniques like this I stop and go back to the beginning. We have positive test results we inappropriately call ‘cases’ and we have viral tests (PCR/LFD) that are chest-deep in controversy.

The Game

We all know the game. Asymptomatic folk will stick a swab up their nose repeatedly until they get a positive result; somehow this makes them feel better. This sounds acceptable until you realise the jargon is disguising some seriously disturbing behaviour; that is, somebody who is completely and utterly healthy is checking to see whether they are carrying a virus that isn’t making them ill, and they won’t rest until a test that can churn out false positive results (and uses primers that are not novel or unique to SARS-COV-2) tells them they they just might be carryin…