Principal diagnosis data cubes

The data cubes can be used to explore a range of clinical data related to hospital separations. 

The Excel data cube workbooks consist of two sheets:

• 5-character PDx Counts Data contains separation statistics by principal diagnosis by age group by sex by same-day status.
• 5-character PDx Counts Summary contains a pivot table showing separation statistics by principal diagnosis. This pivot table can be modified to various levels by right clicking on the table, selecting ‘Show Field List’, and then modifying the pivot table as desired (see Figure 1).
  • Variables in the ROWS list can be removed to disaggregate at higher levels.
  • Variables such as age group, sex and/or same-day flag can be dragged to the COLUMNS list to disaggregate by these variables.

Figure 1: 5-character PDx counts summary pivot table

Source: Separation statistics by principal diagnosis (ICD-10-AM 11^th edition), Australia, 2021-22 data cube. 

The cubes contain information on the number of separations and number of patient days. Once the cube has been aggregated/disaggregated to the desired level, average length of stay can be calculated as number of patient days/number of separations.

Tips on using the Principal Diagnosis data cube

Note that the use of the different ICD editions in the data cubes over time means that data across years may not be exactly comparable.

Within the cubes, users can view the diagnoses by working down from the broad chapter level in the ICD classifications to more specific categories (i.e. principal diagnosis code), as illustrated below:

• ICD Chapter
  • ICD Sub-Chapter
    • ICD 3-character code
      • ICD 4-character code (where relevant)
        • ICD 5-character code (where relevant)

For example:

• Endocrine, nutritional and metabolic diseases (E00-E89)
  • Disorders of thyroid gland (E00-E07)
    • Other hypothyroidism (E03)
      • Congenital hypothyroidism without goitre (E03.1).

Users of the data cubes are likely to require some familiarity with ICD-9-CM and ICD-10-AM. Users will generally need to know what chapter the information they are looking for is in, to work down to more specific levels of detail. More information about the breakdowns and categories used within the data cube are given below.

International Classification of Diseases (ICD)

Principal diagnoses are classified according to either the International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) or the International Statistical Classification of Diseases and Related Health Problems, Tenth Revision, Australian Modification (ICD-10-AM). The use of the different classifications (ICD-9-CM and ICD-10-AM) in the data cubes means that data from 1998–99 onwards may not be exactly comparable with the earlier data (1993-94 to 1997-98). In addition, there are some differences in the coding between ICD-10-AM editions and these will be reflected in the cube.

The following is a list of the ICD disease chapters used in the data cube and the code ranges covered by each: