How lag in reporting Covid-19 deaths is affecting true picture of second wave

A total of 1,325 UK Covid-19 deaths were reported on Friday January 8 – the highest number for a single day since the coronavirus began, beating even the equivalent peak during the first wave last spring.

But this figure included deaths that had taken place over a number of days, including some from as far back as December 25.

There has always been a lag in the reporting of Covid-19 deaths, but over Christmas and New Year this lag became longer than usual.

Bank holidays slowed the registration of deaths, while some nations did not issue any updates for a number of days.

This has caused a 'backlog' of Covid-19 deaths that are only now being reported – and which is affecting the true picture of the second wave of the virus.

To get a better understanding of what is happening right now, it is important to look at the data for when people are actually dying, not just when those deaths are being reported.

The Government publishes a full breakdown of these statistics.

In all cases they are for people who died within 28 days of testing positive for Covid-19.

HEALTH Coronavirus Deaths
HEALTH Coronavirus Deaths

Looking at the data for when these deaths have occurred, the latest available figure for the whole of the UK is for January 7, which shows that 721 deaths took place on this date.

The number is likely to be revised upwards as more deaths are registered.

It is some way below the 1,162 deaths reported on January 7, however.

On the previous day, January 6, 771 deaths took place.

Again, this is below the 1,041 deaths that were reported on this date.

In both cases, the number of deaths reported on these dates included deaths that had taken place over the Christmas and the New Year period.

By contrast, while 407 deaths were reported on January 4, the latest data shows that 767 deaths occurred on that date.

Coronavirus graphic
Coronavirus graphic

By concentrating just on the figures for when deaths have taken place, we can see that – rather than soaring from 407 and 1,162 in the space of three days – the number has in fact been on a slow upwards curve for the past month, climbing from around 400 deaths a day in early December to nearly 800 deaths a day in early January.

This gives us a much clearer picture of how the second wave has unfolded so far.

But thanks to the lag between a death taking place and it being officially reported, it is hard to tell precisely where we are in the trajectory of the second wave.

We probably won't know we've passed the peak until a couple of weeks after it has happened.

The 771 deaths that took place on January 6 is the highest number for a single day so far during the second wave.

This number could be revised upwards as more deaths are reported, however.

It is also likely that, once all the data is in, we will see similarly high numbers for the next few weeks – and possibly even higher.

For the time being, the "deadliest day" of the coronavirus pandemic in the UK remains April 8 2020.

On this date there were 1,072 deaths of people who had tested positive for Covid-19 in the previous 28 days.