UK introduces new methodology to estimate excess deaths

The new method uses age-specific mortality rates to estimate the expected number of deaths used in the calculation of excess mortality – the difference between the actual and expected number of deaths – rather than death counts.

According to the ONS, this means trends in population size and age structure will be taken into account.

The new approach also accounts for trends in population mortality rates, the ONS said.

A comparison of the two methods found similar estimations of excess deaths during the Covid-19 pandemic – on an annual basis, the new method estimates 76,412 excess deaths in the UK in 2020, compared with 84,064 estimated by the old method.

However, for 2023, there is a greater difference in the number of excess deaths estimated by the new method – 10,994, which is 20,448 fewer than the previous approach.

Daniel Ayoubkhani, ONS, said: “During the peak-pandemic years, we saw dramatic increases in mortality rates. It was a stark example of a public health threat resulting in many more deaths than we would have expected in a ‘normal’ year. 

“In the spirit of continuous improvement, we’ve been working with independent experts, and those across government and the devolved nations, to develop a common UK-wide approach.

“Using our new methodology, this release shows tragically there were an estimated 11,000 excess deaths in 2023. This is lower than our previous estimate because our new method accounts for the growth and ageing of the population. These are key factors in understanding how many deaths we would expect to see and whether the actual number of deaths is below, or above, this estimate.   

“Looking more closely at the last months of 2023, there were actually negative excess deaths, meaning fewer deaths than average being registered.”