Angela Rayner’s testing numbers are not quite right

"The government's latest figures show that there were an average of 62,000 people tested per day, not 500,000. The Prime Minister has said that testing capacity is at 300,000, but the average is 62,000 a day. How does he explain this?"

Angela Rayner MP, 16 September 2020

During Prime Minister’s Questions (PMQs) on Wednesday, Labour’s Deputy Leader, Angela Rayner, compared the government’s Covid-19 testing capacity with the number of people being tested each day. However, she used numbers that measure different things, which makes it misleading to compare them.

What do the numbers mean?

Ms Rayner used two different testing capacity figures. The first—500,000 tests per day—is a government target that it intends to achieve by the end of October. The Prime Minister had mentioned this in his response to her previous question.

The second—300,000 tests per day—is the closer figure to the UK’s published test capacity when Ms Rayner was speaking. We can’t find an example of the Prime Minister claiming this figure, although for most of the summer, the UK’s total published test capacity (including for antibody tests) has been around 300,000 a day.

The most relevant figure on capacity now would be around 240,000 tests a day, which is the UK’s most recently published total Pillar 1 and 2 lab capacity. This counts how many diagnostic tests the labs say they can process, which are the ones that show whether someone currently has the virus. (The “62,000 people” tested figure Ms Rayner used comes from the week ending 2 September, but testing capacity then was about the same.)

Who are these 62,000 people?

As Ms Rayner said, this is the average number of “people tested per day”, but it is not a measure of the number of tests being used, because some people may be tested more than once.

It also does not include all the people being tested in the UK.

The figure comes from the latest Test and Trace figures at the time, which showed about 437,000 people being newly tested in the week ending 2 September, equivalent to about 62,000 a day. These figures had been used in a Sunday Times report at the weekend. More recent figures, published after PMQs, on Thursday, show a rise to 571,400 people newly tested in the week to 9 September, equivalent to about 82,000 a day.

However, these Test and Trace figures only cover England, so more people would have been tested in the other nations. Moreover, they only count those people who are newly tested, meaning that they have not been tested before.

In reality, many people are tested more than once for Covid-19, for instance as part of regular monitoring in their workplace, or so a doctor can check whether they still have the disease. If we included all these people, the figure would rise—but we don’t know how much.

So how many people are we testing?

We have contacted the Department of Health and Social Care (DHSC) to ask how many people in total are being tested for Covid-19, but have not been able to get an answer.

DHSC referred us to the “number of people tested” section in its methodology note, which explains that “it does not reflect the volume of tests carried out each week, especially given the importance of regularly testing workers in social care settings”.

Is testing failing to deliver its capacity?

We have said before that the government’s published capacity figure might not tell us how many tests it can carry out in practice.

The government itself also admits that “operational issues at labs can result in labs performing below capacity”.

However, we can’t measure the shortfall by comparing the figures that Ms Rayner used.