As discussed in a previous ONS blog, fundamental to any method for estimating excess deaths is the question, how many deaths do we expect there to be in normal conditions; in other words, what would “normal” mortality levels look like? The current approach used by ONS and the devolved administrations provides a comparison between the number of deaths registered in the current year and the average number over a recent five-year period. For example, excess mortality in 2019 was estimated from data covering 2014 to 2018. 2020 was excluded from subsequent calculations to avoid distortion due to the extremely high number of death registrations, particularly during the first wave of the COVID-19 pandemic. For 2020 and 2021, the average was calculated over 2015 to 2019, and for 2022, it was calculated over 2016 to 2019 plus 2021.

The weakness of this approach is that it doesn’t take into account the ageing and growing population of the UK (all else being equal, more people means more deaths, particularly if a greater share of the population are elderly); nor does it reflect recent trends in population mortality rates, which were generally falling until 2011 before levelling off until the onset of the pandemic.

UK HAS A PROBLEM: Excess deaths are up a staggering 22% among 1 to 14-year-olds.

Notably, this trend didn’t start until “the magic juice started to be issued to children later in 2021.”

Importantly, this approach moves away from averages drawn from raw numbers and instead uses age-specific mortality rates. This means when we ask that first question – how many deaths would we expect there to be? – we take into account how the population has grown and aged over time. The models also account for trends and seasonality in population mortality rates, and allow for estimates of excess deaths to be broken down by age group, sex, and constituent countries of the UK and English region.