False negative Lateral Flow Tests (FOI)
False negative Lateral Flow Tests (FOI)Produced by the Freedom of Information office
Authored by Government of Jersey and published on 14 January 2022.
Prepared internally, no external costs.
Since Individual Lateral Flow tests were mailed out, are statistics being kept on the negative lateral flows which later result on positive PCR tests:
Specifically for direct contacts of active cases who will be taking lateral flow tests (which are negative) until their PCR test shows positive?
In the absence of any such data, how is the government assessing the reliability of lateral flow tests, especially where negative regarding the false negative rate?
The false-negative rate is the proportion of infected people who get a negative test: According to statistics published earlier this year by NHS Test and Trace and Public Health England, there is a LFT false-negative rate of around 50% relative to a PCR (polymerase chain reaction) test. The LFT picks up only around half of infected people without symptoms, so even with a negative test you could still be infectious: rapid tests are not green lights.
Do the Jersey statistics tally with the UK findings?
No. Statistics on false-negative Lateral Flow Test (LFT) rates are not held. Additionally, not all negative LFTs are reported so this would result in unreliable statistics. Article 3 of the Freedom of Information (Jersey) Law 2011 has therefore been applied.
No. Statistics on this are not held. Direct contacts are only categorised as such for their first LFT after being identified as a direct contact. After this point, if they were to test positive on an LFT or start to show symptoms, their following PCR would be categorised as 'individual seeking healthcare'. Article 3 of the Freedom of Information (Jersey) Law 2011 has therefore been applied.
The Government of Jersey only uses tests that have been approved by the Medicines and Healthcare products Regulatory Agency (MHRA) and thoroughly assessed by Public Health England Porton-Down as meeting an agreed set of standards, including a minimum specificity and sensitivity and overall reliability. Lateral Flow Testing is approved by the MHRA as a reliable means of testing for COVID-19.
Jersey does not independently further assess testing methods, as our resources and expertise would not add anything to the processes the UK government has in place. There is a list of approved products and a link to the protocol here:
Outcome of the evaluation of rapid diagnostic assays for specific SARS-CoV-2 antigens (lateral flow devices) (www.gov.uk)
Statistics on false-negative rates are not held so do not tally with UK data. Article 3 of the Freedom of Information (Jersey) Law 2011 has been applied.
Article 3 - Meaning of “information held by a public authority”
For the purposes of this Law, information is held by a public authority if –
(a) it is held by the authority, otherwise than on behalf of another person; or
(b) it is held by another person on behalf of the authority.