Public Accountability Unit
T 020 8327 6920
Wellington House
133-155 Waterloo Road
London SE1 8UG
www.gov.uk/phe
By email
xxxxxxxxxxxxxxxxxxxxxxx@xxxxxxxxxxxxxx.xxx
Our ref: 12/01/nk/2430
09 February 2021
Dear B Jones
Re: Mask / face covering - what is the 'best available evidence' and what is the
NHS Covid-19 treatment protocol
Thank you for your request received on 12 January 2021 addressed to Public Health
England (PHE). In accordance with Section 1(1)(a) of the Freedom of Information
Act 2000 (the Act), I can confirm that PHE partly holds the information you have
specified.
Request
"The best available scientific evidence is that, when used correctly, wearing a
face covering may reduce the spread of coronavirus droplets in certain
circumstances, helping to protect others."
I would like to know:
1a) What the "best available" scientific evidence is as of Jan 2021?
1b) Who decided that this piece of evidence is the "best available" and why?
I can confirm that PHE does hold the information specified. PHE has carried out a rapid
evidence review on face coverings.
The rapid review is exempt under Section 21 of the Act because it is reasonably
accessible by other means, and the terms of the exemption mean that we do not have to
consider whether or not it would be in the public interest for you to have the information.
However, for your convenience I have provided the link below to the updated review as
of 29 January 2021:
https://phe.koha-ptfs.co.uk/cgi-bin/koha/opac-retrieve-
file.pl?id=d86880bf65bd6b18eae21aa3bdaf2a4b
Regarding treatment of Covid-19 patients in hospital:
2) What is the standard or generally standard treatment protocol for Covid-19
patients who are hospitalised?
I can confirm that PHE partly holds the information specified. However is exempt under
Section 21 of the Act because it is reasonably accessible by other means, and the terms
of the exemption mean that we do not have to consider whether or not it would be in the
public interest for you to have the information. However, for your convenience I have
provided the link below to the Guidance for maintaining services within health and care
settings.
https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attach
ment_data/file/954690/Infection_Prevention_and_Control_Guidance_January_2021.
pdf Under Section 16 of the FOI Act, public authorities have a duty to provide advice and
assistance. Accordingly, you may wish to contact the National Health Service (NHS) who
may be able to provide further information around hospital protocol.
Regarding Covid "case" diagnosis:
3a) What is the cycle threshold (CT) used in the PCR 'tests' by the NHS?
3b) Has the CT used always been the same? If not, what changes have been
made and when?
PHE can confirm it holds this information for PHE laboratories. However, to retrieve and
extract the information to respond to your request as it stands would exceed the cost
limit of £600. The cost limit is calculated at a staff rate time at £25 per person per hour
working for 24 hours to respond to the request. Therefore, this information is exempt in
accordance with Section 12 of the Act.
The Cycle Threshold varies between the various platforms used within each testing
laboratory, and is not therefore uniform. There is correlation between some Platform
types, where all parts of the process are similar. Every PHE laboratory has determined
the limit of detection for SARS-CoV-2 across all assays used for patient testing.
Additionally, every PHE laboratory has in place a strategy for the confirmation of positive
results when the screening result was above the threshold identified in the screening
assays.
PHE does not hold this information for non-PHE laboratories. Many laboratories
contribute to the government’s testing programme and PHE does not maintain central
records of testing undertaken in each lab.
Under Section 16 of the FOI Act, public authorities have a duty to provide advice and
assistance. Accordingly, you may wish to contact the National Health Service (NHS)
You may also find the publication on ‘understanding cycle threshold (Ct) in SARS-CoV-2
RT-PCR’ useful;
https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attach
ment_data/file/926410/Understanding_Cycle_Threshold__Ct__in_SARS-CoV-2_RT-
PCR_.pdf If you have any queries regarding the information that has been supplied to you,
please refer your query to me in writing in the first instance. If you remain dissatisfied
and would like to request an internal review, then please contact us at the address
above or by emailing
xxx@xxx.xxx.xx.
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Please note that you have the right to an independent review by the Information
Commissioner’s Office if a complaint cannot be resolved through the PHE
complaints procedure. The Information Commissioner’s Office can be contacted by
calling the ICO’s helpline on 0303 123 1113, visiting the ICO’s website at
www.ico.org.uk or writing to the ICO at Wycliffe House, Water Lane, Wilmslow,
Cheshire, SK9 5AF.
Yours sincerely
FOI Team
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