Deaths from COVID-19 by Location and Age Groups March 2020-February 2022

Methodology for coding of deaths

The figures in this Frontier Series Output are based on deaths that have occurred in Ireland between 1^st March 2020 and 28^th February 2022, have been registered with the General Register Office (GRO) and subsequently notified to the Central Statistics Office (CSO). These figures are provisional. Final data is published in annual reports.

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” (World Health Organization, 2016, p.31).

The UCOD is classified according to the World Health Organization's International Statistical Classification of Diseases and Related Health Problems 10th Revision (WHO, ICD-10). The hierarchy in which the causes are written on the death certificate impacts on the assignment of the UCOD.

From 1st January 2018, the CSO is using IRIS software to assign the UCOD. IRIS is a European developed automated coding software, endorsed by Eurostat and is maintained by the IRIS institute to include all WHO updates.

Deaths due to COVID-19

The corresponding ICD-10 codes for COVID-19 are

• U07.1 (virus identified) where COVID-19 was confirmed by laboratory testing irrespective of severity of clinical signs or symptoms; and
• U07.2 (virus not identified) where COVID-19 was clinically-epidemiologically diagnosed but laboratory testing is inconclusive or not available (including probable or suspected 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.

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.

The coding of causes of deaths in the CSO applies all ICD-10 rules in a consistent manner. The CSO relies on the data provided by medical certifiers who assure the accuracy and completeness of causes of deaths on the certificates, including the correct causal sequence which affects the selection of the underlying cause of death.

NUTS2 and NUTS3 Regional Authority areas

The Nomenclature of Territorial Units for Statistics (NUTS) were created by Eurostat in order to define territorial units for the production of regional statistics across the European Union. In 2003 the NUTS classification was established within a legal framework (Regulation (EC) No 1059/2003).

As the administrative territorial breakdown of EU Member States is the basis of the NUTS classification, changes made under the 2014 Local Government Act prompted a revision to the Irish NUTS 2 and NUTS 3 Regions. These changes included the amalgamation of the local authorities of Tipperary North and South, Limerick City and County Councils and Waterford City and County Councils. In addition, three Regional Assemblies were established (Northern & Western, Southern, Eastern & Midland).

The main changes at NUTS 3 level are the transfer of South Tipperary from the South-East into the Mid-West NUTS 3 region and the movement of Louth from the Border to the Mid-East NUTS 3 Region. There are now three NUTS 2 Regions which correspond to the Regional Assemblies established in the 2014 Local Government Act and are groupings of the new NUTS 3 Regions. The revisions made to the NUTS boundaries have been given legal status under Commission Regulation (EU) 2016/2066. The new NUTS 2 and NUTS 3 structure and classification are displayed in the table below:

NUTS Regional Authority Areas 

From the 1st January 2018 an Amendment of the Eurostat Nomenclature of territorial units for statistics (NUTS classification) legislation came into effect. This reflects the new regional assembly structure and the other changes to the Local Government Act for Tipperary North, Tipperary South and Limerick and Waterford City and County Councils.

Up to December 2017 regional classifications were based on the classification used by Eurostat. The NUTS3 regions corresponded to eight Regional Authorities established under the Local Government Act, 1991 (Regional Authorities) (Establishment) Order, 1993, which came into operation on 1 January 1994. The NUTS2 regions, which were proposed by Government and agreed by Eurostat in 1999, are groupings of the NUTS3 regions. The composition of the regions is set out below.  

References

World Health Organization (1979) Medical Certification of Cause of Death: Instructions for Physicians on Use of International Form of Medical Certificate of Cause of Death (4th edition). Geneva: World Health Organization.

World Health Organization (2016) International Statistical Classification of Diseases and Related Health Problems 10th Revision – Volume 2 Instruction Manual (5th edition). Geneva: World Health Organization.