Notes on interpreting HIPE data

Points to remember

Each HIPE discharge record represents one episode of care and patients may have been admitted to more than one hospital with the same or different diagnoses. In the absence of a Unique Patient Identifier the records therefore facilitate analyses of hospital activity rather than incidence of disease.

Coverage

Any longitudinal analysis of HIPE data should take account of the fact that coverage of HIPE data will have changed over the period. Details of the coverage of HIPE are available from HIPE reports.

Updates in coding schemes

The coding scheme used to code diagnoses and surgical procedures prior to 2005 was the International Classification of Diseases, 9th Revision, Clinical Modification known as ICD-9-CM. Since the 1st of January 2005 all discharges have been coded using ICD-10-AM, International Statistical Classification of Diseases and Related Health Problems, Tenth Revision, Australian Modification, 4th Edition. As a result of this change in the classification scheme from ICD-9-CM to ICD-10-AM, data prior to 2005 are not directly comparable to data from 2005 onwards. For futher details on the coding classifications used to code discharges see the Clinical Coding Classifications section.

Changes in collection of variables

For details of changes and updates in the data collected please refer to the HIPE Instruction Manuals, Coding Notes and HIPE reports.

The example below details the change in number of diagnoses and procedures collected over time.