Question to the Department of Health and Social Care:

To ask Her Majesty's Government, further to the Written Answer by Lord Bethell on 10 December (HL10847), whether they will now answer the question put, namely, whether the operational false positive rate for polymerase chain reaction COVID-19 tests is regularly determined by inserting samples into the system that cannot be positive; and what is the false positive rate for such samples.

Information regarding the assessment of false positives was not held in the format requested due to the challenges in estimating clinical sensitivity. This is part due to a lack of a generally accepted reference standard to compare reverse transcription polymerase chain reaction results.

Currently samples are not placed into the system to test operational sensitivity. The Department has undertaken substantial work with Porton Down and the Milton Keynes Lighthouse Laboratory to conduct temperature and long-term stability experiments on sample collection kits to ensure swabs meet an appropriate standard for testing.