History of Coding in Ireland

All HIPE discharges from 1st January 2015 are coded using ICD-10-AM/ACHI/ACS 8th Edition.

All HIPE discharges from 1st January 2009 to 31st December 2014 were coded using ICD-10-AM/ACHI/ACS 6th Edition.

All HIPE discharges from 1st January 2005 to 31st December 2008 were coded using ICD-10-AM the International Statistical Classification of Diseases and Related Health Problems, Tenth Revision, Australian Modification in conjunction with the Australian Classification of Health Interventions (ACHI) 4th Edition (July 2004).

With effect from January 1, 1990 the clinical modification version of the ninth revision of the International Classification of Diseases, known as ICD-9-CM, was in use in Ireland for coding both diagnoses and procedures within HIPE. The October 1, 1988 version of ICD-9-CM was effective over the period 1990-1994 inclusive and the October 1, 1994 version of ICD-9-CM was introduced to code data from 1995 to 1998 inclusive. Beginning in 1999, the ICD-9-CM version introduced in October 1, 1998 was used for coding morbidity data within the HIPE system for all discharges to 31.12.2004.

The ICD-9-CM coding scheme was the only major internationally used integrated coding scheme for diagnoses and procedures to be reviewed and updated annually. The availability of updates for the coding schemes attempts to keep pace with the developments in medical practice. While a commitment to annual updates may be excessive for a small system like the Irish system, the availability of such updates meant that important revisions could be introduced without delay.

A full update of the ICD-9-CM coding scheme occurred approximately every four or five years within Ireland depending on the scale of developments in the intervening years. ICD-9-CM was not updated in October 1999 due to Y2K pressures.

For information on the coding schemes used between 1969 and 1989 please refer to the Activity in Acute Public Hospitals in Ireland Report 1990-1999.

The publication Updating Clinical Coding in Ireland: Options and Opportunities provides background to the decision on using ICD-10-AM / ACHI / ACS.