Transparency data

Weekly statistics for rapid asymptomatic testing in England: 18 February to 24 February 2021

Updated 23 April 2021

Applies to England

This week the number of PCR and LFD tests conducted by lower-tier local authority and by test result are published in the accompanying data tables for the first time.

Introduction

This statistical publication aims to provide information on rapid testing for people without COVID-19 symptoms in England. This includes:

• the number of LFD tests conducted in England by test result
• the number of LFD tests conducted in England by region
• the number of LFD tests conducted in England in education settings

This publication focuses on rapid testing using lateral flow device (LFD) tests, however polymerase chain reaction (PCR) tests are included where appropriate, either for comparison or where regular asymptomatic PCR testing is used. All data used in the report can be found in the ‘Tests conducted’ data tables on the weekly collection page. This includes information on both LFD and PCR tests at lower-tier local authority level.

The figures in this report are not deduplicated and refer only to the number of tests taken, not the number of people tested. Because people can have more than one test, the data should not be compared with prevalence or case positivity rates.

The figures in this report include LFD tests which were registered through the National Testing Programme digital infrastructure. They do not currently include LFD tests conducted where the tests were not registered via this route. LFD tests for the majority of secondary care NHS staff and some testing within the private sector testing are therefore not included.

See the About this data section for more information.

Background

Types of tests

PCR tests

PCR tests check for the genetic material of the coronavirus in the sample, which is taken using a swab and is processed in a lab via a polymerase chain reaction (PCR). This type of test is predominantly used for:

• anyone who has symptoms
• to confirm a positive LFD test result in certain use cases, including:
  • self-reporting LFDs^{[footnote 1]}
  • cross channel hauliers
• regular asymptomatic testing in social care.

Lateral flow device tests

LFD tests, often referred to as rapid tests, test for the presence of proteins called ‘antigens’ which are produced by the virus. They are swab tests that give results in 30 minutes or less, without the need for processing in a laboratory. These tests are primarily used for those who do not have symptoms.

From 21 October 2020, LFD tests were made available in limited capacity except where rapid testing pilots were conducted. Since then, their availability has expanded to a broader range of settings.

Rapid testing for people without symptoms

Rapid testing using LFD tests is currently being offered to people who do not have symptoms, in a range of different settings.

Some LFD testing is carried out at asymptomatic test sites, which are deployed in a range of community settings such as universities, schools, care homes and workplaces. They are also set up by local authorities as part of the community testing program. Testing at these sites is assisted: a person will take a swab test under the supervision of a trained operator who then processes the test then reads and records the result.

Some LFD testing is carried out entirely by individuals themselves (that is an individual takes their own test, unassisted, and reports their own result), however in these specific situations (see the Types of tests section above) if a positive test result is returned the individual is required to take a confirmatory PCR test. For more information see understanding lateral flow tests for people without symptoms.

LFD tests conducted, England^{[footnote 2]}

The number of LFD tests conducted has been increasing overall since their introduction in October 2020. In the latest week (18 February to 24 February), 2,226,982 LFD tests were conducted, which is over 16 times higher than mid-December. The number of LFD tests conducted has increased in the latest week after decreasing in the previous week due to half term.

In comparison, in the latest week 1,099,613 PCR tests were conducted. This is the fifth successive week for which more LFD tests were conducted than PCR tests. Previously the number of PCR tests conducted had always been higher than LFD tests. This reflects the increasing use of LFD tests, as well as a decrease in symptomatic people taking a PCR test due to decreasing COVID-19 prevalence.

PCR and LFD tests have different uses and are therefore applied in different situations (see the Types of tests section above for more information). The primary purpose of rapid LFD testing is to identify people with COVID-19 who do not have symptoms. As the number of LFD tests conducted increases, more asymptomatic positive cases are identified earlier and therefore they are less likely to transmit the virus to their contacts.

Of the LFD tests conducted in the latest week, 5,336 tests returned a positive result, and 2,218,756 tests returned a negative result. Since LFD tests were introduced, 92,307 positive results and 14,358,137 negative results have been reported.

Figure 1: number of LFD and PCR tests conducted, England

This data can be found in the ‘table_1’ and ‘table_2’ tabs of the ‘Tests conducted: 28 May 2020 to 24 February 2021 data tables’ on the weekly collection page.

LFD tests conducted by region, England

The number of LFD tests conducted has been increasing overall across all regions between late December 2020 and the beginning of February 2021. However, the number of LFD tests taken for all regions decreased between 11 February and 17 February which coincided with half-term, and the number of tests has begun to increase again in the latest week. Between 18 February and 24 February 2021, the most LFD tests were conducted in South East followed by North West, similar to previous weeks.

Figure 2: LFD tests conducted by region, England^{[footnote 3]}

This data can be found in the ‘table_4’ tab of the ‘Tests conducted: 28 May 2020 to 24 February 2021 data tables’ on the weekly collection page.

LFD tests conducted in education settings, England

The rapid testing operation has been rolled out differently across the different education settings, as summarised in the table below. For more information see the NHS Test and Trace statistics methodology.

Setting	Testing started	Frequency	Group tested
Primary schools, school-based nurseries and maintained nursery schools	18 January 2021	Twice a week	Staff
Primary schools, school-based nurseries and maintained nursery schools	1 March 2021	Twice a week	Households and bubbles of staff and students
Secondary schools and colleges	4 January 2021	Once a week then increased to twice a week	Staff and students*
Secondary schools and colleges	1 March 2021	Twice a week	Households and bubbles of staff and students
Higher education	27 November 2020	Twice before leaving and twice on return	Staff and students
Higher education	25 January 2021	Twice a week	Staff and students

*Testing of secondary school students only includes children of critical workers and those in vulnerable groups who are currently attending school.

LFD tests conducted by phase of education

The number of LFD tests conducted within primary schools, school-based nurseries and maintained nursery schools increased substantially between 14 January 2021 and the beginning of February to over 700,000 tests in a week. Between 11 and 17 February the number of tests conducted decreased compared to the previous week, which coincided with half term. In the latest week the number of tests conducted has begun to increase again to 587,943 tests although this is still impacted by half term. 701 positive test results were returned in the latest week within primary schools and nurseries, a decrease from 750 positive results in the previous week.

Similarly, within secondary schools and colleges, the number of LFD tests conducted increased gradually since the week commencing 31 December 2020 to almost 400,000 in the week commencing 4 February. The number of tests conducted decreased between 11 and 17 February compared with the previous week, which coincided with half term. This has begun to increase again in the latest week to 288,958 LFD tests. The number of positive test results had been decreasing since the week commencing 14 January 2021 until the week commencing 11 February. However, in the latest week 189 positive test results were returned, an increase compared to 121 in the previous week, although this coincides with half term.

54,048 LFD tests were conducted in the latest week in higher education which has remained broadly consistent since the beginning of January. The number of LFD tests conducted in higher education peaked between 3 December to 9 December 2020 which coincides with students getting tested to enable them to travel home for the winter break. There has been a decrease in positive results in higher education seen over the past month, with 87 positive test results returned in the latest week.

The number of positive test results is not published as a proportion of the total tests conducted due to the data quality. In addition, because there are differences in the testing operation between the different phases of education, they cannot be directly compared. See the Data quality section below for more information.

Figure 3: number of LFD tests conducted in education, by phase of education, England

This data can be found in the ‘table_6’ tab of the ‘Tests conducted: 28 May 2020 to 24 February 2021 data tables’ on the weekly collection page.

LFD tests conducted by staff and students in secondary schools^{[footnote 4]}

In the latest week 196,923 LFD tests were taken by staff in secondary schools, in comparison with 75,121 tests taken by students. The number of tests conducted by secondary school staff had been increasing rapidly between the beginning of January and the week beginning the 4 February. This then declined in the week commencing 11 February, coinciding with half-term. The number of tests taken by staff have increased again in the latest week, although the latest week is still impacted by half-term.

Similarly, tests conducted by secondary school students have increased in the latest week after the decrease seen previously, although the latest week is still impacted by half term.

Figure 4: number of LFD tests conducted by staff and students in secondary schools, England

This data can be found in the ‘table_7’ tab of the ‘Tests conducted: 28 May 2020 to 24 February 2021 data tables’ on the weekly collection page.

About this data

Lateral flow device tests were first made available from 21 October 2020 in England. This data contains LFD tests reported through the existing National Testing Programme digital infrastructure and does not include LFD tests conducted where the tests were not registered via this route that is used to collect data for this report.

The following use cases for LFD tests are not currently reporting results digitally into Test and Trace systems, and therefore are excluded from this report:

• testing for the majority of NHS secondary care staff
• testing for some staff in private sector industries

In these cases, test results should be reported directly into Public Health England. In future, all LFD tests will be reported via the existing National Testing Programme digital infrastructure and will be included.

A full explanation of the data sources and methods used to produce these statistics can be found in the NHS Test and Trace statistics methodology.

Data quality

Given the importance of this service and the commitment of NHS Test and Trace to be open and transparent with the public it serves, this data is being released at the earliest possible opportunity. However, this data should be treated with caution whilst the understanding of the data and its quality improves.

The requirement for care home staff to register negative LFD test results was suspended between 31 December 2020 and 15 January 2021 inclusive, following a change in guidance issued on 23 December 2020 to increase testing in care home staff. As a result, a proportion of LFD tests conducted on care home staff will not be included for these dates.

An LFD test produces a result on the device almost immediately, without it being automatically recorded, therefore some results might not be captured. For settings where self-reporting LFD testing procedures^{[footnote 5]} are in place, it is likely that the number of tests conducted are underreported. It is however their statutory duty to do so, and easier reporting tools are being rolled out to support these individuals to report their tests as quickly and efficiently as possible. It is possible that tests with a negative result are more likely to be affected, therefore it is not advisable to calculate a positivity rate with the data.

Positive test results are not published as a proportion of the total number of tests conducted. There are several reasons why it is not advisable to calculate a positivity rate with this data:

• the number of tests conducted is not deduplicated and refers to the number of tests taken and not the number of people tested. Because people can have more than one test, the number of tests conducted therefore cannot be compared with prevalence or case positivity rates

• rapid testing is primarily used for repeat testing of asymptomatic individuals and the frequency of testing varies across different settings, therefore positivity rates would not be directly comparable

• the potential underreporting of tests conducted by individuals self-reporting is more likely to affect negative test results than positives thus skewing any positivity rate calculation

More information on data limitations and how the figures in this publication can and can’t be used is outlined in the NHS Test and Trace statistics methodology.

Future developments

We continue to explore the feasibility of adding new breakdowns to the publication on rapid testing to support user needs. Over the coming months, we intend to make data available on the following:

• rapid testing for asymptomatic NHS staff

• asymptomatic testing in care homes

• rapid testing in public and private industries

• community testing programme

For feedback and any further questions, please contact [email protected].

1. Self-reported results from LFDs are where the individual carrying out the test on themselves is expected to report their own test and subsequent result. ↩

2. Counts of LFD tests conducted do not include tests which weren’t reported through the National Testing Program digital infrastructure. ↩

3. Absolute number of tests conducted in each region and does not take into consideration population of regions. ↩

4. Staff and students are identified using age as a proxy; therefore it is not appropriate to breakdown tests in universities by staff and student using this methodology. ↩

5. Self-reporting LFDs are where the individual carrying out the test on themselves is expected to report their own test and subsequent result. ↩