You asked
Please could you let me know where you obtained your excess mortality data from? E.g. death certificates, reports
Also, how do you obtain the figures from other countries and any other information about how you obtain death data.
We said
Thank you for your request.
Excess mortality was investigated in our publication on Comparisons of all-cause mortality between European countries and regions: January to June 2020. In addition, we present excess mortality figures where relevant in other ONS publications such as in the weekly deaths bulletin in order to discern where deaths are higher or lower than previous years' data.
The data for our mortality publications come from the information recorded when deaths are registered. This process, and the responsible organisation, varies between countries.
For England and Wales, we use Office for National Statistics (ONS) data. This is based on information recorded by the General Register Office (GRO) when deaths are certified and registered. More information about the process of registering a death and the information that is collected can be found in the section 'Information collected at death registration' in our User guide to mortality statistics.
Some of our mortality publications include data for the rest of the UK, such as the weekly deaths bulletin. For Scotland, we use Scotland National Records Scotland (NRS) data collected by National Records of Scotland, and for Northern Ireland we use Northern Ireland Statistics and Research Agency (NISRA) data collected by the General Register Office for Northern Ireland.
For the other countries, included in the article on Comparisons of all-cause mortality between European countries and regions, we used data from the European Union Statistics Office (Eurostat) from contributing nations of the European Union (EU) and European Free Trade Association. All data used in the article is publicly available on the Eurostat website, as well as accompanying metadata.
There are clear criteria set out by Eurostat for data to be submitted to their database, based on official recording of deaths occurring in all settings, to maximise comparability. For some countries, the data is based on the date a death occurred, while for others it is based on the date a death was registered. Data for the UK nations are reported by date of registration, which is typically up to a week after date of death. More information can be found in the country comparability section of the article. The reasons for using Eurostat as the source of data for this article is found in the Measuring the data section.
Excess mortality is calculated from the data above by comparing the actual of deaths in 2020 to the 'expected' number of deaths derived from previous years' data. We use the five-year average of the number of deaths in the years 2015 to 2019 to calculate the 'expected' number of deaths.
There are different methods of comparing actual and expected deaths to calculate excess mortality. Three methods, age-standardised mortality rates (ASMRs), relative age-standardised mortality rates (rASMRs) and relative cumulative age-standardised mortality rates (rcASMRs), were used in our international comparisons paper. Details of each of these methods can be found in the 'Measuring the data' section of this article along with a description of two alternative methods, P-scores and Z-scores.