Notes on the data: Aboriginal hospital admissions

Aboriginal admissions by selected principal diagnosis (including by sex and by broad age group); and from potentially preventable conditions (including by vaccine-preventable, acute and chronic, and by broad age group), 2017/18 to 2019/20

Policy context:  Admission to hospital is a formal process, and follows a decision made by an accredited medical practitioner at that hospital that a patient needs to be admitted for appropriate management or treatment of their condition, or for appropriate care or assessment of needs [1].

Patients are usually admitted to hospital either as an emergency or as a booked admission. Emergency admission patients are usually admitted through the Accident and Emergency Department: these are seriously injured or ill patients who need immediate treatment. Most patients receive hospital-based services as a booked (elective) admission, either as a same-day patient or an inpatient. A same-day patient comes to hospital for a test or treatment and returns home the same day. An overnight admission is recorded where a patient receives hospital treatment for a minimum of 1 night (that is, the patient is admitted to and separated from the hospital on different dates) or longer in the hospital.

The majority of people who have had an episode of care in a hospital express satisfaction with the service when they leave [1]. However, admission to hospital carries with it a risk of harm. In Australia rates of serious adverse medical events are similar to those found in studies in the United States, with 0.3% of hospital admissions associated with an iatrogenic (medically caused) death and 1.7% associated with major iatrogenic disability [2]. Admission to hospital per se also carries a risk of adverse events, in addition to those related to any medical treatment undertaken. These include a risk of cross-infection, injury, or rarely, death.

In 2018–19, Aboriginal and Torres Strait Islander people had higher separation rates than that for other Australians. Excluding separations for dame-day renal dialysis, separation rates for Indigenous Australians were 38% above the rates for other Australians. For dialysis, the rate was 12 times the rate for other Australians); for Diseases of the respiratory system, Endocrine, nutritional and metabolic diseases (which includes Diabetes mellitus); Diseases of the skin and subcutaneous tissue; and Certain infectious and parasitic diseases, the rates were around double (higher by 2.07 times, 2.23 times, and 1.85 times, respectively) [3].

References

1. Australian Institute of Health and Welfare 2016. Admitted patient care 2014–15: Australian hospital statistics. Health services series no. 68. Cat. no. HSE 172. Canberra: AIHW.
2. Runciman WB, Webb RK, Helps SC et al. A comparison of iatrogenic injury studies in Australia and America II: reviewer behaviour and quality of care. The International Journal of Quality in Healthcare 2000;12(5):379-88.
3. PHIDU (download the Indigenous Status Comparison workbook here).

Notes:  

Introduction

Where used, the terms ‘Aboriginal’ and ‘Indigenous’ refer to Aboriginal and Torres Strait Islander people.

The data presented are of the number of separations, or completions of the episode of care of a patient in hospital, where the completion can be the discharge, death or transfer of the patient, or a change in the type of care (e.g., from acute to rehabilitation). In this atlas the term 'admission' is used in place of the technically-correct 'separation'. As these data relate to short-term episodes of care, and not to long-stay episodes, the number of admissions is similar to the number of separations in any year.

Potentially preventable hospitalisations are admissions from a specified range of conditions where hospitalisation could have been potentially been prevented through the provision of appropriate individualised preventative health interventions and early disease management usually delivered in primary care and community-based care settings (including by general practitioners, medical specialists, dentists, nurses and allied health professionals). Data definitions for potentially preventable hospitalisations are in the National Healthcare Agreement: PI 18-Selected potentially preventable hospitalisations, 2017 available through METeOR (METeOR ID: 630028).

Note that the data are based on the count of all admissions. As such, repeat admissions for one person are counted as separate admissions. In addition, patients admitted to one hospital and transferred to another hospital are counted as separate admissions. Although such transfers occur in all areas, they are likely to be more prevalent from regional to metropolitan areas, thereby resulting in a higher rate of admissions in regional areas compared to the metropolitan areas; in addition, certain conditions are more likely to result in transfers.

Caution should be used in the interpretation of these data because of jurisdictional differences in data quality as well as under-identification of Aboriginal and Torres Strait Islander people. The AIHW found that nationally, about 88% of Indigenous Australians were identified correctly in hospital admissions data in the 2011–12 study period, and the ‘true’ number of separations for Indigenous Australians was about 9% higher than reported (for further information see item at Reference [1], above).

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.

Exclusions

The national data exclude well babies (i.e., babies not admitted for acute care) who are nine days old or less, other than the second or subsequent live born infant of a multiple birth whose mother is currently an admitted patient (for further information see item at Reference [1], above).

Same-day admissions for dialysis for kidney disease have been excluded from the data in this atlas for the categories of admissions for males, females and total persons, and admissions by age. These admissions have been excluded as they represent many repeat visits by a relatively small number of patients, who may have multiple admissions in a week: their inclusion can dramatically alter the geographic distribution of other categories of admissions (see the separate note for Same-day hospital admissions for renal dialysis, Aboriginal personsfor further details); these data are presented separately. All other same-day admissions are included.

Publishing of Queensland data by Indigenous Area

As requested by Queensland Health, the Indigenous Area (IAREs) below were combined to ensure confidentiality.

Details of data presented

Refer to separate note for Same-day hospital admissions for renal dialysis, Aboriginal persons

Separate data are presented for:

1. Admissions by sex (excluding same-day admissions for renal dialysis - (Z491 to Z492)):

• Total admissions, Aboriginal persons
• Male admissions, Aboriginal males
• Female admissions, Aboriginal females

2. Admissions by age (excluding same-day admissions for renal dialysis - (Z491 to Z492)):

• Total admissions, Aboriginal persons aged 0 to 14 years
• Total admissions, Aboriginal persons aged 15 to 24 years
• Total admissions, Aboriginal persons aged 25 to 44 years
• Total admissions, Aboriginal persons aged 45 to 64 years
• Total admissions, Aboriginal persons aged 65 years and over

3. Admissions by selected principal diagnosis:

Note: Bracketed numbers below refer to codes in the International Classification of Diseases (ICD-10-AM) chapters.

• Admissions for infectious and parasitic diseases (A00-B99), Aboriginal persons
• Admissions for all cancers (C00-D48), Aboriginal persons
• Admissions for endocrine, nutritional and metabolic diseases (E00-E90), Aboriginal persons
  • Admissions for diabetes (E10 to E14.9), Aboriginal persons
• Admissions for mental health related conditions (F00-F99), Aboriginal persons
  • Admissions for mood affective disorders (F30-F39), Aboriginal persons
• Admissions for nervous system diseases (G00-G99), Aboriginal persons
• Admissions for eye and adnexa diseases (H00-H59), Aboriginal persons
• Admissions for ear and mastoid process diseases (H60-H95), Aboriginal persons
• Admissions for circulatory system diseases (I00-I99), Aboriginal persons
  • Admissions for ischaemic heart disease (I20-I25), Aboriginal persons
  • Admissions for heart failure (I50), Aboriginal persons
• Admissions for respiratory system diseases (J00-J99), Aboriginal persons
  • Admissions for asthma (J45-J46), Aboriginal persons
  • Admissions for chronic obstructive pulmonary disease (COPD) (J40-J44), Aboriginal persons
• Admissions for digestive system diseases (K00-K93), Aboriginal persons
• Admissions for skin and subcutaneous tissue diseases (L00-L99), Aboriginal persons
• Admissions for musculoskeletal system and connective tissue diseases (M00-M99), Aboriginal persons
• Admissions for genitourinary system diseases (N00-N99), Aboriginal persons
  • Admissions for chronic kidney disease (49.0, E10.2, E11.2, E13.2, E14.2, I12, I13, I15.0, I15.1, N00-N07, N08, N11, N12, N14, N15, N16, N18, N19, N25-N28, N39.1, N39.2, E85.1, D59.3, B52.0, Q60-Q63, T82.4, T86.1), Aboriginal persons
• Admissions for pregnancy, childbirth and the puerperium (O00-O99), Aboriginal females aged 15 to 44 years
• Admissions for congenital malformations, deformations and chromosomal abnormalities (Q00-Q99), Aboriginal persons
• Admissions for injury, poisoning and other external causes (S00-T98), Aboriginal persons

4. Admissions by selected principal diagnosis and age:

Note: Bracketed numbers below refer to codes in the International Classification of Diseases (ICD-10-AM) chapters.

• Admissions for infectious and parasitic diseases (A00-B99), Aboriginal persons aged 0 to 14 years
• Admissions for infectious and parasitic diseases (A00-B99), Aboriginal persons aged 15 years and over
• Admissions for respiratory system diseases (J00-J99), Aboriginal persons aged 0 to 14 years
• Admissions for respiratory system diseases (J00-J99), Aboriginal persons aged 15 years and over
• Admissions for digestive system diseases (K00-K93), Aboriginal persons aged 0 to 14 years
• Admissions for digestive system diseases (K00-K93), Aboriginal persons aged 15 years and over
• Admissions for skin and subcutaneous tissue diseases (L00-L99), Aboriginal persons aged 0 to 14 years
• Admissions for skin and subcutaneous tissue diseases (L00-L99), Aboriginal persons aged 15 years and over
• Admissions for injury, poisoning and other external causes (S00-T98), Aboriginal persons aged 0 to 14 years
• Admissions for injury, poisoning and other external causes (S00-T98), Aboriginal persons aged 15 years and over

Note: Bracketed numbers below refer to codes in the International Classification of Diseases (ICD-10-AM) chapters.

• Admissions for transport crash Injury (V00-V99), Aboriginal persons
• Admissions for falls (W00-W19), Aboriginal persons
• Admissions for injury due to exposure to inanimate mechanical forces (W20-W49), Aboriginal persons
• Admissions for injury due to exposure to animate mechanical forces (W50-W64), Aboriginal persons
• Admissions for intentional self-harm (X60-X84), Aboriginal persons
• Admissions for assault (X85-Y09), Aboriginal persons
• Admissions for all diagnosis of injury or poisoning, by external cause , Aboriginal persons

• Same-day admissions for dialysis for kidney disease, Aboriginal persons

• Admissions for potentially preventable conditions, Aboriginal persons

• Admissions for potentially preventable conditions, Aboriginal persons aged 0 to 14 years
• Admissions for potentially preventable conditions, Aboriginal persons aged 15 to 24 years
• Admissions for potentially preventable conditions, Aboriginal persons aged 25 to 44 years
• Admissions for potentially preventable conditions, Aboriginal persons aged 45 to 64 years
• Admissions for potentially preventable conditions, Aboriginal persons aged 65 years and over

• Admissions for pneumonia and influenza, Aboriginal persons
• Admissions for total vaccine-preventable conditions, Aboriginal persons

• Admissions for acute cellulitis, Aboriginal persons
• Admissions for acute convulsions and epilepsy, Aboriginal persons
• Admissions for acute dental conditions, Aboriginal persons
• Admissions for acute ear, nose and throat infections, Aboriginal persons
• Admissions for acute urinary tract infections, including pyelonephritis, Aboriginal persons
• Admissions for total acute conditions, Aboriginal persons

• Admissions for chronic angina, Aboriginal persons
• Admissions for chronic asthma, Aboriginal persons
• Admissions for chronic congestive cardiac failure, Aboriginal persons
• Admissions for chronic obstructive pulmonary disease (COPD), Aboriginal persons
• Admissions for chronic diabetes complications, Aboriginal persons
• Admissions for chronic iron deficiency anaemia, Aboriginal persons
• Admissions for total chronic conditions, Aboriginal persons

Confidentiality of data

Counts of less than five admissions have been suppressed.

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

Numerator:  Admissions for the above categories

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 (respective population); and/or indirectly age-standardised ratio, based on the Indigenous standard population (2017, 2018, 2019 and 2020 average estimated resident population, as calculated by PHIDU.

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.

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