Dear Ed,  

Re: England and Wales Mortality Statistics produced by the Office for National Statistics (ONS)

 Thank you for your letter of 4 May 2023 communicating the findings of OSR’s recent review into ONS mortality statistics, with a focus on compliance with the Quality pillar of the Code of Practice for Statistics. As noted in your correspondence, there has been an increased interest in mortality statistics since the onset of the pandemic, and we appreciate this independent look into our statistics and the recommendations that have come from it. 

In your letter you focussed on six areas. These were: 

  • The quality of mortality statistics 
  • Communication of the quality assurance processes 
  • Reporting mortality data by the date of registration as opposed to the date of death 
  • User need for data on deaths by date of occurrence 
  • Deaths registered by coroners 
  • ONS’s review of methods 

The quality of mortality statistics 

 We appreciate your confirmation that the mortality statistics produced by ONS are of good quality, and the strengths recognised in such areas as detailed documentation, quality assurance processes, and organisational relationships. 

Communication of the quality assurance processes

You noted that you were satisfied with the description of methods in the Quality and Methodology Information (QMI) but would like to see more information presented about the quality assurance process. We update the QMI and User guide to mortality statistics annually alongside our Deaths registered in England and Wales annual release. We will ensure that in future editions of these publications more information is included about the quality assurance processes. The next release is planned for this autumn. With support from the MQD team, we will engage with users to identify the appropriate level of detail to provide on quality assurance in the QMI to meet their needs, and we would appreciate the opportunity to share updates on this work with you.  

With regard to dual running, we currently employ this as part of our quality process, but in the future we will be working with MQD to explore development of reproducible analytical pipelines and ensure we are following current best practice in this area.  

Reporting mortality data by the date of registration as opposed to the date of death

You commented that ONS should ensure that when mortality data are reported, it is made clear that it is done so by the date that the death was registered, not the date that the death occurred; and that the rationale for this needs to be made clearer. We put a great deal of importance on the transparency of both our findings and the methodology we use. In recent years we have made sustained efforts to label and explain mortality outputs drawing attention to this issue. We appreciate that the rationale for our approach could be made clearer and we will include this point in the updated QMI and User guide, and in the methods section of all mortality publications. It is important to note that timeliness would not in itself be improved through publication by date of occurrence and could only be increased by reducing the time taken to register and process deaths, or by obtaining a suitable new source of data on death occurrences. These are issues which we keep continuously under review in consultation with the other government departments involved. We are also planning to undertake more engagement with our users, as noted in the below sections. 

User need for data on deaths by date of occurrence

 You commented on the need to investigate user need for publishing occurrence data in more of our releases. We currently publish occurrence data as part of our Deaths registered weekly, Monthly mortality analysis and Impact of registration delays releases. There are also specific topic-based publications that use occurrence data due to the time of death being important, for example on Winter mortality. As part of the internal Methods and Quality Directorate (MQD) review, we plan to engage with users more widely and will cover this issue in the process and respond to the user needs expressed. 

Deaths registered by coroners

The possibility of improving the timeliness of information from coroners or receiving information on deaths that have been referred to coroners has been raised on a number of occasions and faces both legal and practical obstacles. We plan to continue engagement with the Chief Coroner and other stakeholders, in partnership with DHSC, and would welcome your participation in these discussions. 

ONS’s review of methods

We are currently working with MQD and their review may provide us with further recommendations to improve our mortality statistics for users. We will share this information with you on completion of the review. 

Yours sincerely, 

Nick Taylor 

Deputy Director for Epidemiology and Global Health Analysis 


Related Links:

Ed Humpherson to Nick Taylor: England and Wales Mortality Statistics produced by the Office for National Statistics (ONS)