Key findings 

• A total of 22,416 deaths occurred between 01 January 2020 and 31 October 2020 and were registered with the General Registrar's Office (GRO) and subsequently notified to the CSO
• Cancer (7,269) and Diseases of the circulatory system (5,886) were the leading Underlying Cause of Death (UCOD) for all deaths registered in the first 10 months of 2020, accounting for 13,155 deaths or 58.7% of deaths

COVID-19 Related Deaths

• COVID-19 was the fourth UCOD and accounts for 1,462 deaths or just over 6.5% of total deaths in the year to date
• COVID-19 was:
  • the fifth highest UCOD in the 65 – 79 and the 80 and over age categories
  • the sixth highest for the 50 – 64 age group
  • the eight highest in the 25 – 49 age group
  • not in the top 10 UCOD for the under 25 age group

Other Causes of Death

• Cancer was the highest UCOD in Ireland for both males and females, accounting for 3,897 male deaths and 3,372 female deaths
• Cancer and Diseases of the circulatory system were either the first or second highest UCOD for all deaths currently registered in each of the 25 and over age groups
• Congenital malformations, deformations & chromosomal abnormalities were the highest UCOD in the under 25 age category accounting for 48 deaths (29.6%)
• In the 80 or over age category, Mental & behavioural disorders accounted for 1,062 deaths (8.7%), which includes conditions such as dementia

(Note: Deaths from external causes of injury such as poisoning, road traffic accidents and deaths from intentional self-harm will be under represented in this report as they are likely to be referred to the Coroner for further investigation. This can result in the registration of these types of deaths being delayed.)

Introduction

The analysis included in this Frontier Series Output is based on deaths that have occurred between 01 January 2020 and 31 October 2020 and have been registered with the General Registrar's Office and subsequently notified to the Central Statistics Office (CSO).

On receipt of the data, one of the key tasks for the CSO is to assign the Underlying Cause of Death (UCOD). The UCOD refers to the disease or injury that initiated the train of morbid events leading directly to death or the circumstances of the accident or violence that produced the injury.

All deaths, including COVID-19 deaths, are treated in the same way i.e. each record is assigned an UCOD based on the narrative details reported on the death certificate, in line with the World Health Organisation (WHO) International Statistical Classification of Diseases and Related Health Problems (ICD-10) classification.  (The hierarchy in which the causes are written on the death certificate impacts on the assignment of the UCOD.)

There are a number of important points to consider:

• It is important to note that there will be a number of deaths where COVID-19 will not be assigned as the UCOD and therefore, the COVID-19 deaths in this analysis, will vary from those put into the public domain by the Department of Health.
• It is also worth noting that the tables in this analysis report COVID-19 related deaths in the category "COVID-19, virus identified and virus not identified" i.e. COVID-19, where there was a confirmed laboratory test or where there was a clinical or epidemiological diagnosis but the laboratory testing was inconclusive or not available.
• A COVID-19 death is defined, for surveillance purposes, as a death resulting from a clinically compatible illness in a probable or confirmed COVID-19 case, unless there is a clear alternative cause of death that cannot be related to COVID-19 (e.g. trauma). There should be no period of complete recovery between the illness and death. Additional information on the approach to coding COVID-19 as the UCOD is included in the Background Notes below.
• Legally, in Ireland, a death can be registered up to three months after the date of occurrence and therefore not all deaths that took place between 01 January 2020 and 31 October 2020 are included in this. The CSO estimates that approximately 2,500 to 3,500 deaths remain to be registered covering the period of analysis in this output. However, the number of deaths yet to be registered are of a scale that they are unlikely to significantly impact the ranking of the categories included in this analysis - with the exception of deaths assigned an UCOD of External causes of injury and poisoning which are likely to be underrepresented in this release.
• Deaths assigned an UCOD of External causes of injury and poisoning (including deaths from road traffic accidents and deaths from intentional self-harm), are likely to be underrepresented in this analysis as such deaths are very frequently reported to the Coroner’s Office for further investigation. This can then result in such deaths being registered late (more than three months after the date of occurrence) and therefore have not yet been reported to the CSO.

Underlying Cause of Death by Sex

An analysis of the top 10 Underlying Causes of Death (UCOD)  by sex shows that:

• Cancer (Neoplasms) was the highest UCOD in Ireland for both males and females, accounting for 3,897 male deaths and 3,372 female deaths. Total deaths from Cancer were 7,269, accounting for just over 32.4% of all deaths in the first 10 months of the year
• Diseases of the circulatory system were the second highest UCOD for both males and females. This cause of death accounted for 5,886 deaths or just under 26.3% of all deaths in the first 10 months of the year
• COVID-19, virus identified and virus not identified, was the fourth highest cause of death for males (732 deaths) and the fifth highest cause of death for females (730 deaths). In total, COVID-19, virus identified and virus not identified, accounted for 1,462 deaths or just over 6.5% of all deaths in the year to date

Underlying Cause of Death by age group

65 to 79 age category

• A total of 7,023 deaths occurred for persons aged 65 to 79 between 01 January 2020 and 31 October 2020, and have been registered with the General Registrar's Office and subsequently notified to the CSO
• Cancer was the highest UCOD accounting for 3,066 deaths or almost 43.7% of this age category
• Diseases of the circulatory system were the second highest UCOD for people in this age category and accounts for 1,480 deaths (21.1%) over the period covered in this analysis
• The third highest UCOD for persons aged 65-79 was Diseases of the respiratory system (755 deaths or 10.8%)
• COVID-19, virus identified and virus not identified is the fifth highest UCOD for this age category and accounts for 379 deaths or 5.4%

50 to 64 age category

• A total of 2,300 deaths occurred for persons aged 50 to 64 over the period of analysis and Cancer was the highest UCOD in this age category accounting for 1,281 deaths or 55.7% of all deaths
• Diseases of the circulatory system was the second highest UCOD and accounts for 420 deaths (18.3%)
• COVID-19, virus identified and virus not identified, is the sixth highest UCOD for persons aged 50 to 64 and accounts for 76 deaths (3.3% of all deaths in this age category)

25 to 49 age category

• A total of 707 deaths occurred for persons aged 25 to 49 over the period of analysis and Cancer was again the highest UCOD in this age category accounting for 340 deaths (48.1%)
• Diseases of the circulatory system is the second highest UCOD and accounts for 124 deaths or 17.5%
• COVID-19, virus identified and virus not identified was the eighth highest UCOD for this age category and accounts for 15 deaths or 2.1% of all deaths

Under 25 age category

• A total of 162 deaths occurred for persons aged under 25 over the period of analysis
• Congenital malformations, deformations & chromosomal abnormalities was the highest UCOD, accounting for 48 deaths (29.6%) followed by Certain conditions originating in the perinatal period, accounting for 38 deaths or 23.5%
• COVID-19, virus identified and virus not identified, was not in the top 10 ranked UCOD for this age category

• Deaths due to external causes of injury and poisoning (this includes deaths from road traffic accidents and deaths from intentional self-harm) are likely to be underrepresented in this analysis. This UCOD is likely, based on data for previous years, to be the highest UCOD for persons aged under 25 once additional registrations and late registrations are received for the period

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Background Notes

Methodology & Coding

The figures in this Frontier Series Output See Link are based on deaths that have occurred between 1 Jan 2020 and end October 2020, been registered with the General Registrar's Office and subsequently notified to the Central Statistics Office (CSO). It should also be noted that these figures are provisional.

The Underlying Cause of Death is classified according to the World Health Organisation's International Classification of Diseases, Version 10 (ICD-10)

All deaths currently registered in the period have been included in the statistics and some cases have been assigned a provisional cause of death pending the outcome of further enquiries. 

Final data is published in annual reports and is based on the date the death occurred.

From the 1st January 2018 the CSO is using new automated software called IRIS for selecting the underlying cause of death code.  The coding system has been developed and is maintained by the IRIS core group to code mortality data and is the preferred coding tool for European countries.

Definition of death due to COVID-19

A COVID-19 death is defined, for surveillance purposes, as a death resulting from a clinically compatible illness in a probable or confirmed COVID-19 case, unless there is a clear alternative cause of death that cannot be related to COVID-19 disease (e.g. trauma). There should be no period of complete recovery between the illness and death. 

Confirmed COVID-19 case

A person with laboratory confirmation of COVID-19 infection, irrespective of clinical signs and symptoms. 

The Cause of Death is completed by the medical practitioner who attended the deceased and COVID-19 is reported on a death certificate as any other cause of death, and rules for selection of the single underlying cause are the same as for influenza (COVID-19 not due to anything else). Note that a death certificate has an implied hierarchy and there is an implied ‘due to’ between each line in Part 1 with the underlying cause of death written in the lowest used line in part 1 of the certificate.  All contributing comorbidities (immune system problem, chronic diseases...) should be reported in part 2.

ICD-10 Cause of Death (Mortality) coding of COVID-19

The Mortality Codes the CSO uses are the following World Health Organisation’s (WHO) ICD-10 codes to classify COVID-19. 

New ICD-10 codes for COVID-19:

• U07.1 COVID-19, virus identified 

Confirmed by laboratory testing irrespective of severity of clinical signs or symptoms.

• U07.2 COVID-19, virus not identified

Clinically-epidemiologically diagnosed COVID-19 but laboratory testing is inconclusive or not available (Probable COVID-19 or Suspected COVID-19).

COVID-19 should be recorded on the medical certificate of cause of death for ALL decedents where the disease caused, or is assumed to have caused, or contributed to death.

Although both categories, U07.1 (COVID-19, virus identified) and U07.2 (COVID-19, virus not identified) are suitable for cause of death coding, it is recognized that in many countries detail as to the laboratory confirmation of COVID-19 will NOT be reported on the death certificate. In the absence of this detail, it is recommended, for mortality purposes only, to code COVID-19 provisionally to U07.1 unless it is stated as “probable” or “suspected”.

Here, on the International Form of Medical Certificate of Cause of Death, are examples of how to certify this chain of events for deaths due to COVID-19.

 

Persons with COVID-19 may die due to other conditions such as myocardial infarction. Such cases are not deaths due to COVID-19.

Additional WHO cause of death certification links

Cause of Death on the Death Certificate: Quick Reference Guide (Section 7.1.2).

International form of medical certificate of cause of death (Section 7.1.1). 

Comorbidities

There is increasing evidence that people with existing chronic conditions or compromised immune systems due to disability are at higher risk of death due to COVID-19. Chronic conditions may be non-communicable diseases such as coronary artery disease, chronic obstructive pulmonary disease (COPD), and diabetes or disabilities. If the decedent had existing chronic conditions, such as these, they should be reported in Part 2 of the medical certificate of cause of death.

Select COVID-19, specified as suspected (the case has virus not confirmed) as underlying cause of death.

The certifier should have added the HIV disease as a comorbidity in Part 2 of the certificate, however the selection rules of ICD allow to identify COVID-19 as underlying cause of death. (COVID-19) is reported in a sequence ending with a terminal condition (Acute respiratory distress syndrome due to COVID-19).

The international rules and guidelines for selecting the underlying cause of death for statistical tabulation apply when COVID-19 is reported on a death certificate but, given the intense public health requirements for data, COVID-19 is not considered as due to, or as an obvious consequence of, anything else in analogy to the coding rules applied for INFLUENZA. Further to this, there is no provision in the classification to link COVID-19 to other causes or modify its coding in any way.

A set of additional categories has been agreed to be able to document or flag conditions that occur in the context of COVID-19.

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