You asked
Please can you provide me with details of the following:
The total number of PCR tests done each day since they started, and the number of each of those that tested positive. Also it would be convenient to have a third spreadsheet column showing the number of positive tests as a percentage of the total number.
As an additional FOI request, please provide, for each PCR test lab, from the start of when they were offered:
The amplification cycle rate used
If it changed through time, then state the date each time it changed and what the new cycle rate became
If the cycle rates used were different between those who were vaccinated and those not vaccinated, then explain why that is the case, and what scientific justification there is for that.
We said
Thank you for your request.
The PCR tests used for our survey are accredited tests and part of the national testing programme. The swabs are processed by the Lighthouse Laboratories in Glasgow, and the UK Biobank centre are responsible for setting the Ct threshold of positive tests. More information about our swab procedure can be found in our methodology article or our study protocol. You may also be interested in our recent technical article on positivity after vaccination.
In the technical dataset accompanying our latest bulletin, you can find the genetic lineages and Ct values of a sample of the positive tests returned by the participants in our study on tab 1a.
In the same dataset, on tab 2f, you can find the total number of tests performed daily since the survey began.
In order to provide the positivity per test done in this format, we would need to create bespoke analysis. Under the Freedom of Information Act 2000, Public Authorities are not obligated to create information in order to respond to requests. We therefore consider this to be information not held. However, in the England dataset accompanying our bulletin in the UK Summary - Positivity tab, you can find the official weekly estimates for positivity, broken down by UK nation over time.