I looked up the protocols used by a couple of different tests of a SARS-cov-2 lateral flow immunochromatographic assays. There is no way to know for certain if it is the same assay, but I will assume yes. They used PCR positive samples to verify the results, which makes it problematic, but it was a reasonably low PCR cycle so it could be worse.
The test results were not great. The average agreement was around 80%. That suggests around a one in five chance of disagreement between a low cycle PCR test and the lateral flow assays tested. No real statistical conclusions can be made from this, but I can guesstimate a one in twenty chance of being positive on both and not having the virus (assuming the PCR test is 25 cycles or less).
If PCR test taken is a higher cycle (per the WHO protocol) that would be closer to a one in five chance of a false positive for the lateral flow assay for both. Maybe one in ten. I trust the lateral flow assay more than the PCR for this purpose, but without a verification process other than PCR its really an unknown.
I looked up the protocols used by a couple of different tests of a SARS-cov-2 lateral flow immunochromatographic assays. There is no way to know for certain if it is the same assay, but I will assume yes. They used PCR positive samples to verify the results, which makes it problematic, but it was a reasonably low PCR cycle so it could be worse.
The test results were not great. The average agreement was around 80%. That suggests around a one in five chance of disagreement between a low cycle PCR test and the lateral flow assays tested. No real statistical conclusions can be made from this, but I can guesstimate a one in twenty chance of being positive on both and not having the virus (assuming the PCR test is 25 cycles or less).
If PCR test taken is a higher cycle (per the WHO protocol) that would be closer to a one in five chance of a false positive for the lateral flow assay for both. Maybe one in ten. I trust the lateral flow assay more than the PCR for this purpose, but without a verification process other than PCR its really an unknown.
I looked up the protocols used by a couple of different tests of a SARS-cov-2 lateral flow immunochromatographic assays. There is no way to know for certain if it is the same assay, but I will assume yes. They used PCR positive samples to verify the results, which makes it problematic, but it was a reasonably low PCR cycle so it could be worse.
The test results were not great. The average agreement was around 80%. That suggests around a one in five chance of disagreement between a low cycle PCR test and the lateral flow assays tested. No real statistical conclusions can be made from this, but I can guesstimate a one in twenty chance of being positive on both (assuming the PCR test is 25 cycles or less) and not having the virus.
If it is a higher cycle PCR (per the WHO protocol) that would be closer to a one in five chance of a false positive for the lateral flow assay for both. Maybe one in ten. I trust the lateral flow assay more than the PCR for this purpose, but without a verification process other than PCR its really an unknown.