Evidence doesn’t show 400,000 people have long Covid ‘right now’

“It’s estimated that up to 400,000 people are living with the debilitating effects of long Covid”.

“The current estimate for the number of people who have long Covid is nearing 400,000.”

“We reckon there is at least 400,000 people right now in the UK that have long Covid.”

Liberal Democrat MP Layla Moran claimed during Prime Minister’s Questions on 10 February that up to 400,000 people are living with long Covid in the UK. She tweeted a video clip of her saying this, with the caption: “Up to 400,000 people are living with long Covid right now”. 

Ms Moran, who is chair of the All Party Parliamentary Group on coronavirus, also made this claim in an interview with Metro on the same day, and during an appearance on LBC on 5 February.

For some people, symptoms of Covid-19 can last for weeks or months after the infection has gone. This is known as long Covid.

There is very little available data on long Covid, and so it is difficult to get an accurate picture of how many people are suffering with it. However, the estimate given by Ms Moran is not an accurate reflection of the limited data that exists. 

Her figure of 400,000 is based on figures published by the Office for National Statistics (ONS) in December. These suggest around 20% respondents to the UK Coronavirus Infection Survey who tested positive for Covid-19 between 22 April and 7 December experienced symptoms for five weeks or longer, and around 10% did so for 12 weeks or longer. The ONS warned these are experimental statistics and are not yet fully developed. 

The latest government figures show around four million people have tested positive for Covid-19 in the UK since the start of the pandemic. Ms Moran’s figure focuses on those who have experienced symptoms for 12 weeks or longer, and is based on the fact that 10% of 4 million is 400,000. 

As this figure only includes people who have tested positive for Covid-19, it is likely it misses some people with long Covid who were never tested, particularly at the start of the pandemic when testing was less common.

However, Ms Moran’s calculation is extremely crude and probably not a good estimate. The ONS data is concerned with people who experienced symptoms for 12 weeks or more. But just because someone experienced symptoms for more than 12 weeks last year does not necessarily mean they would still be experiencing symptoms now. But, under Ms Moran’s calculation, 10% of everyone who had ever tested positive for Covid-19 would still be included as experiencing long Covid symptoms “right now”. 

The ONS has tried to estimate the number of people living with symptoms lasting between five and 12 weeks in England. It has suggested this figure was around 186,000 in the week beginning 22 November, and around 300,000 in the week beginning 27 December.

However, the ONS has not attempted to put a number on the number of people living with symptoms for 12 weeks or more, as Ms Moran has. The ONS told Full Fact this was because insufficient sample sizes of people who had suffered symptoms for this long meant it was not possible to make reliable inferences from the data.

Full Fact put these concerns about the 400,000 estimate to Ms Moran, who said that “more data is needed to improve the estimated prevalence of long Covid”. 

She added: “We will continue to use the ONS’s ‘1 in 10’ figure – the best we have - to estimate the number of people living with long Covid until the UK Government, or anyone else, is able to better refine these numbers. 

“We can’t accept any argument that implies, infers or suggests the lack of data on long Covid is a valid reason to not discuss the estimated number of people it may affect. 

“We have always been very clear we are only communicating estimations, and being able to produce a more accurate figure, higher or lower, would be a fantastic step forward.”