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Weekly statistics for rapid asymptomatic testing in England: 25 March to 31 March 2021

Published 8 April 2021

Applies to England

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
• the number of LFD and PCR tests conducted in England in care homes

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 below 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
• 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.

Prior to 27 January 2021, if an individual received a positive LFD test result they were required to take a PCR test to confirm this. Between 27 January and 29 March 2021 this was no longer a requirement except for those self-reporting their test result. From 30 March 2021 the requirement to take a confirmatory PCR was reinstated for all positive LFD tests.

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 programme. 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). For more information see understanding lateral flow tests for people without symptoms.

LFD tests conducted, England^{[footnote 1]}

The number of LFD tests conducted has generally increased since their introduction in October 2020. Between 18 February and 17 March, the number of LFD tests conducted rose sharply peaking at 7,659,815, which coincides with return of secondary students to school. Since then, the number of LFD tests conducted has decreased to 5,486,356 tests in the latest week (25 to 31 March 2021), which coincides with the end of the spring term for schools.

In comparison, 996,728 PCR tests were conducted in the latest week (25 to 31 March 2021). This is the tenth 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, 8,374 tests returned a positive result, and 5,471,580 tests returned a negative result. Since LFD tests were introduced, 130,526 positive results and 43,603,134 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_3’ tabs of the ‘Tests conducted: 28 May 2020 to 31 March 2021 data tables’ on the weekly collection page.

LFD tests conducted by region, England

The number of LFD tests conducted has decreased across all regions in the latest week which coincides with the end of the spring term for schools. This follows a peak in the number of LFD tests between 11 March and 17 March which coincided with return of secondary students to school. Between 25 March and 31 March 2021, the most LFD tests were conducted in the South East followed by the South West.

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

This data can be found in the ‘table_4’ tab of the ‘Tests conducted: 28 May 2020 to 31 March 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.

	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	8 March 2021	Three tests on return (spaced 3-5 days apart) then twice a week	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

*Students in this time period only included children of critical workers and those in vulnerable groups who were currently attending school.

Between 27 January and 30 March 2021, staff, students, household bubbles and support bubbles who tested positive after using a home LFD test kit were required to take a confirmatory PCR test, and those who tested positive from an LFD test taken at an on-site test centre did not. From 30 March 2021, the requirement to take a confirmatory PCR test was reinstated for all positive LFD tests. For more information on the testing methods for the different phases of education see the NHS Test and Trace statistics methodology.

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. In the latest week the number of tests conducted has decreased to 914,487. 1,555 positive test results were returned in the latest week within primary schools and nurseries, a decrease from 1,918 positive results in the previous week. The overall decrease coincides with the end of spring term.

Similarly, within secondary schools and colleges, the number of LFD tests conducted increased gradually since the week commencing 31 December 2020 to over 400,000 in the week commencing 4 February.

In the latest week, the number of tests has decreased to 2,971,469 compared to the previous week. This follows a peak in the number of secondary school and college tests between 11 March and 17 March which coincides with secondary school students taking 3 tests on their return to school. The decrease in tests in the latest week coincides with the shift to twice-weekly home-testing for students followed by the end of the spring term. The number of positive test results has decreased to 3,474 positive results in the latest week.

The total number of LFD tests taken in secondary schools and colleges includes tests not registered. The full breakdown of tests registered and not registered in secondary schools and colleges is available in ‘table 6’ of the ‘Tests conducted: 28 May 2020 to 31 March 2021 data tables’ on the weekly collection page.

93,008 LFD tests were conducted in the latest week in higher education, which is a slight decrease from 101,822 tests in the previous week. The number of LFD tests conducted in higher education peaked between 3 December to 9 December 2020 which coincided with students getting tested to enable them to travel home for the winter break. 63 positive test results were returned in higher education in the latest week, a slight reduction since the previous 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 31 March 2021 data tables’ on the weekly collection page.

LFD tests conducted by staff, students, household bubbles and support bubbles

In the latest week 472,842 LFD tests were taken by staff in secondary schools, a decrease from the previous week. In comparison, 742,904 tests were taken by staff in primary schools, school-based nurseries and maintained nursery schools.

In the latest week, 1,908,916 tests were taken by students in secondary schools. This is a decrease since the week commencing 11 March, when the number of tests for students in secondary schools peaked. The peak coincided with students each completing 3 tests on their return to school, which has shifted to twice-weekly home-testing in the latest week followed by the end of the spring term.

378,166 tests were taken by individuals that belong to a household bubble of a student or staff member at school or nursery and 37,499 were taken by individuals in their support bubbles. The number of tests conducted by household and support bubbles increased sharply for 2 weeks after they were first reported in the week commencing 4 March. In the past week, tests conducted by household and support bubbles has seen a slight decrease in comparison to the previous week.

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 31 March 2021 data tables’ on the weekly collection page.

Tests conducted and registered to care home settings, England

Asymptomatic testing, using both rapid LFD tests and PCR tests has been rolled out differently across different care home settings and their residents, staff and visitors, as summarised in the table below.

The number of tests conducted in care homes includes staff, residents and visitors tested via test kits directly sent to the care home which were registered. It will not include care home staff residents, or visitors who are tested via a different route, for example at a regional or local test site or a mobile testing unit or tests that were not registered.

For more information see the NHS Test and Trace statistics methodology.

	Dates	Frequency	Test Kit
Care home residents	07/06/2020 - present	Monthly In the event of an outbreak: Day 1 and between days 4-7	PCR
Care home residents	22/02/2021 - present	In the event of an outbreak: Day 1 and between days 4-7 at Health Protection Team discretion	LFD
Care home staff	07/06/2020 - present	Weekly In the event of an outbreak: Day 1 and between days 4-7	PCR
Care home staff	23/12/2020 - present	Twice weekly In the event of a positive case in the care home: Daily until 5 days without a positive	LFD
Care home indoor visitors	08/03/2021 - present	Weekly - essential care givers	PCR
Care home indoor visitors	08/03/2021 - present	Twice weekly – essential care givers	LFD
Care home indoor visitors	02/12/2020 - present*	On arrival	LFD
Care home visiting professionals – CQC inspectors	14/12/2020 - present	Weekly	PCR
Care home visiting professionals – CQC inspectors	22/03/2021 - present	Before visit	LFD
Care home visiting professionals – all other professionals	14/12/2020 - present	On arrival, unless part of a regular testing regime and can provide proof of a negative result within last 72 hours	LFD

*Close contact visits with LFD testing began on 2 December 2020 but ceased on 6 January 2021 because of the national lockdown. Throughout the period of national restrictions, visits were limited to outdoors, in visiting pods, or with a substantial screen; as well as those in exceptional circumstances such as end of life.

PCR and LFD tests conducted and registered to care home settings, England

The number of PCR tests conducted within care homes increased overall from 40,000 tests in the week commencing 25 June 2020 to over 550,000 tests in the week commencing 7 January 2021. This has decreased across the last 2 months to 425,792 tests in the latest week (25 to 31 March 2021) as prevalence and the number of outbreaks has reduced.

The number of LFD tests conducted within care homes increased steeply from the week commencing 10 December 2020 to over 560,000 tests in the week commencing 4 February 2021. Since then, the number of LFD tests conducted has decreased slightly to 511,553 tests in the latest week (25 to 31 March 2021) as prevalence and the number of outbreaks has reduced.

The week commencing the 25 March 2021 was the tenth 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.

Of the LFD tests conducted in the latest week (25 to 31 March 2021), 311 tests returned a positive result, and 511,085 tests returned a negative result. Since LFD tests were introduced, 21,113 positive results and 6,259,579 negative results have been reported.

Figure 5: number of LFD and PCR tests conducted in care homes, England

This data can be found in the ‘table_8’ and ‘table_9’ tab of the ‘Tests conducted: 28 May 2020 to 31 March 2021 data tables’ on the weekly collection page.

LFD testing in care homes by staff and residents

Between 25 March and 31 March, 6,919 LFD tests were conducted by care home residents, which has decreased slightly from 7,203 in the previous week.

Of these, 19 returned a positive result compared to 25 in the previous week, continuing the downward trend from the previous week. This is the eleventh successive week of declining of positive test results.

Figure 6: number of LFD and PCR tests conducted by residents and staff in care homes, England

This data can be found in the ‘table_9’ tab of the ‘Tests conducted: 28 May 2020 to 31 March 2021 data tables’ on the weekly collection page.

LFD testing in care homes by visitors and visiting professionals

In the latest week 10,354 LFD tests were taken by visiting professionals in care homes, in comparison with 43,709 tests taken by visitors. The number of tests conducted by visitors increased steeply from week commencing 11 March although the overall number of LFD tests decreased. This follows a change in the guidance on care home visits from 8 March.

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
• testing for some hauliers, these are published separately see haulier coronavirus testing

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 3]} 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

• rapid testing in public and private industries

• community testing programme

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

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

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

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