Counting deaths involving coronavirus: a year in review
Since before the pandemic the Office for National Statistics has been publishing death registrations in England and Wales on a weekly basis. What was once a little-known dataset has become one of the most important and widely used documents for tracking deaths throughout the Coronavirus (COVID-19) pandemic. Today’s deaths registered weekly in England and Wales marks the end of 2020 death registration. But how does 2020 compare to previous years? Sarah Caul explains the complexities behind mortality comparisons…
2020 was an extraordinary year. This time last year, “novel coronavirus” was still a new mysterious virus. Fast forward two months and on 11th March 2020 the World Health Organisation declared a global pandemic, changing the way we live our lives dramatically.
Throughout the pandemic, the ONS has published vital information including regular mortality statistics but one of the frequently asked questions is “but how does this compare to other years?”
The answer? It’s multi-faceted. There are several ways to measure mortality and to fully understand we must look at this in a number of ways.
The five-year average
Analysis of all-cause mortality allows us to examine the impact of the pandemic not only from deaths due to COVID-19 but also excess deaths that have occurred as a result.
For excess death, we compare numbers and rates to a five-year average, this ensures that we are comparing like for like in terms of life expectancy, advances in healthcare, population size and shape.
2020 was an unprecedented year in many ways, including the number of deaths; the overall number of deaths registered in 2020 was 75,925 higher than we would expect when looking at the five-year average between 2015 and 2019.
Looking at individual years, the number of deaths was 77,161 higher than the number registered in 2019, the biggest year-on-year increase since 1940. 2020 registered 66,431 more deaths than 2018, the year with the highest number of deaths in the previous five years and 82,954 deaths more than 2016, the year with the lowest number of deaths in the previous five years.
Even compared to 10 and 20 years ago, the number of deaths was higher in 2020 by 123,636 and 75,504 respectively.
But for the best comparisons, we really need to look at age-standardised mortality rates.
Age-standardised mortality rates
The population has changed and grown over time, so in many respects you’d expect the number of deaths to have increased which is why it’s important to consider Age-Standardised Mortality Rates (ASMRs)
ASMRs takes into consideration both the population size and age-structure allowing us compare over time. You would expect more deaths in a population with more old people and ASMRs even out the population differences so that you compare like with like. Looking recently, we’ve experienced fluctuating but historically low mortality rates. But the provisional age-standardised mortality rate in 2020 was 1043.5 deaths per 100,000 population around 8% higher than the five year average. This is the highest it has been in more than a decade (since 2008).
Bearing in mind long term improvements in life expectancy, improvements to living standards, the introduction of the NHS and other medical advancements, including mass vaccination programmes which eradicated diseases, mean comparing today’s numbers to the 20th century and late 19th century doesn’t help you understand the current mortality patterns.
Finally, there’s the total death count. Looking at the calendar year – deaths registered between 1st January to 31st December1 – 2020 had the second highest number of death registrations. The provisional number of 608,002 deaths is only lower than 1918, the year of the Spanish flu (deaths from conflicts overseas are not included), which saw 611,861 deaths. These are the only two years since our time series began in 1838 to have more than 600,000 deaths registered.
But comparing 2020 with 1918 is not comparing like for like. The population in England and Wales has increased from 34 million in 1918 to around 60 million today, so per 100,000, more people died in 1918, highlighting the importance of viewing these deaths in a proportionate and balanced way.
The pandemic has undoubtedly had a serious impact on all aspects of life and the known impact on mortality is still in its early stages.
The first registrations of death involving COVID-19 only occurred in March 2020 and throughout the year we have seen 81,653 deaths registered that mentioned COVID-19 on the death certificate. But with the pandemic on-going, we expect to see more deaths above the average, and it is unknown how long repercussions of this pandemic will be felt.
Every death is a tragedy, whether directly or indirectly due to COVID-19 or not due to COVID-19 at all, and our thoughts go out to all those who have lost a loved one over 2020.
1 Please note: total deaths by calendar year covers deaths registered the period 1st January to 31st December 2020 as opposed to weekly deaths data which include four “non-2020 days” covering the period 28th December 2020 – 1st January 2021.