Notes on the data: Hospital admissions

Same-day admissions for dialysis for kidney disease, 2017/18 to 2019/20

Policy context: Same-day admissions for dialysis for kidney disease account for a large proportion of same-day admissions, particularly for Indigenous Australians, who were admitted for dialysis at 12 times the rate for other Australians in 2017/18 to 2018/19 [1].

Reference

PHIDU (download the Indigenous Status Comparison workbook here).

Notes:

Introduction

The data presented are of the number of same-day admissions for dialysis for kidney disease, including both haemodialysis and peritoneal dialysis, International Classification of Disease (ICD-10-AM) codes Z49.1 and Z49.2. There are two main types of dialysis: peritoneal, which occurs inside the body and can be performed almost anywhere, usually in the home setting; and haemodialysis, which occurs outside the body and is most often conducted in a hospital or satellite setting. The reason for presenting these data separately from overnight admissions is that they represent many repeat visits by a relatively small number of patients, who may have multiple admissions in a week. Their inclusion with, for example, admissions of males, or of females can dramatically alter the geographic distribution of these other categories of admissions. This is particularly evident in regional and remote areas where dialysis facilities are located, and where those using them may have moved to live to be near the facility.

Confidentiality of data

Counts of less than five admissions have been suppressed.

Data are not available for private dialysis units in Tasmania, the Northern Territory or the Australian Capital Territory, to protect the confidentiality of the small number of private facilities in these jurisdictions. As a result, where data are published for public dialysis units and all dialysis units, the 'all units' data for these jurisdictions have also been confidentialised, as their publication would allow identification of the confidentialised private dialysis units. The 'all units' data in other jurisdictions have also been confidentialised where publication of public and all units data would allow identification of private hospital data confidentialised due to small cell sizes. The decision was made to confidentialise the 'all units' rather than the 'public' figure as admissions to public dialysis units comprise the majority of admissions, both overall and from the most disadvantaged areas.

Data source of denominator population

There is a substantial difference between the Census counts of Aboriginal and Torres Strait Islander Australians and the estimated resident population (ERP), adjusted for net undercount as measured by the Post Enumeration Survey undertaken by the ABS (the ERP is 17.5% higher for Australia than the Census count). Given this large difference, and as the ABS has not released Aboriginal ERP by age at the Indigenous Area level as used in the Social Health Atlases, PHIDU has calculated an estimated resident population for 30 June 2017, 2018, 2019 and 2020, for the calculation of rates. In this instance, rates of hospitalisation were calculated as the average of these three populations. Further detail can be obtained by contacting PHIDU.

Geography: Data available by Indigenous Area, Primary Health Network, Quintile of socioeconomic outcomes (based on IRSEO) and Remoteness Area

Numerator: Same-day admissions for dialysis for kidney disease - (Z491 to Z492)

Denominator: Estimated resident Aboriginal population, weighted average of PHIDU-estimated populations, June 2017, 2018, 2019 and 2020

Detail of analysis: Indirectly age-standardised rate per 100,000 population; and/or indirectly age-standardised ratio, based on the Australian standard.

Source: Compiled by PHIDU using data from the Australian Institute of Health and Welfare, supplied on behalf of State and Territory health departments for 2017/18 to 2019/20; and weighted average of June 2017, 2018, 2019 and 2020 estimated resident population,as calculated by PHIDU – see Data source of denominator population, above.