[quote JanFebAnyMonth]John Deeks et al's latest review of LFT studies
www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD013705.pub2/full[/quote]
Key sentence being, I think -
"At 0.5% prevalence applying the same tests in asymptomatic people would result in PPVs of 11% to 28% meaning that between 7 in 10 and 9 in 10 positive results will be false positives, and between 1 in 2 and 1 in 3 cases will be missed."
which suggests a massive 70%-90% of LFT positives are wrong, and we are also missing between 33% and 50% of real cases.
Which supports backing up a positive LFT with a PCR. At face value so far our data suggests that 35% ish of positive LFTs are being confirmed by PCR, but of course that doesn't mean the other 65% are confirmed as negative, it could be that people haven't bothered to do a PCR (as it's only in the past week that significant numbers have been encouraged to do so through the schools plan).
So we are, possibly, identifying 50% of schools asymptomatic cases in the current programme but also identifying thousands of false positives.