Statistics on hospitalisation provide some insights into ill-health in the population . They are, however, a fairly poor reflection of the extent and patterns of treatable illness in the community because they only represent illness that is serious enough to require hospitalisation and are influenced to some degree by the geographic accessibility of hospitals and variations in admission policies.
Another limitation of the available hospital statistics as an indicator of the health of the population is that they relate to episodes of hospitalisation rather than to individual patients . Thus, multiple admissions by a relatively small number of patients – as occurs for renal dialysis, for example – limit the inferences that can be drawn about overall health patterns from aggregated statistics. These statistics are, of course, useful in assessing the need for health services, but of far less use in assessing health.
As is the case with other major health-related data collections (such as births and deaths), the identification of Indigenous status in hospital data collections is incomplete. A study of the quality of Indigenous identification in records of public hospital separations in Australia’s states and territories found that nationally 88% of Indigenous patients in public hospitals were correctly identified as such in 2011-12 . The accuracy of the identification of Indigenous people varied between states and territories, from 98% in the NT to 58% in the ACT. The accuracy of identification also varied with remoteness level, from 99% in very remote areas to 77% in major cities. In comparison to a similar study conducted in 2007-2008, there had been little if any improvement to Indigenous identification in public hospital records . In 2007-08, an estimated 89% of Indigenous patients were correctly identified in the records of public hospitals. Since 2007-08, there had been slight improvements to the accuracy of Indigenous identification in Qld, SA, Tasmania (Tas), and the NT . The accuracy of Indigenous identification in NSW, Vic, WA, and the ACT had decreased between 2007-08 and 2011-12.
Of the 9.3 million hospital separations in Australia2 during 2011-12, 366,118 (4.0%) were identified as Indigenous (Table 1) . Around 92% of Indigenous hospital separations were of Aboriginal people, 4% were of Torres Strait Islander people, and 4% were of people who identified as being of both Aboriginal and Torres Strait Islander descent. Around two-fifths (38%) of separations for Indigenous patients were for overnight stays.
In 2011-12, the overall age-standardised separation rate of 973 per 1,000 for Indigenous people was 2.5 times that for non-Indigenous people (Table 1) . The age-standardised separation rate for Indigenous people living in the NT (1,779 per 1,000) was 5.7 times the rate for non-Indigenous people. Around 80% of the difference between national Indigenous and non-Indigenous rates was due to higher separations for Indigenous people admitted for kidney dialysis.
|Source: AIHW, 2013 |
Nationally in 2011-12, hospital separation rates were higher for Indigenous people than for non-Indigenous people in all age-groups, with the highest ratios in the middle adult years (Table 2) (Derived from ).
|Indigenous||Non-Indigenous||Rate ratio||Indigenous||Non-Indigenous||Rate ratio|
|Source: Derived from AIHW, 2013 , ABS, 2009 , ABS, 2012 , ABS, 2013 |
In 2011-12, the most common reason for the hospitalisation of Indigenous people in Australia was for care involving dialysis, which was responsible for 45% of Indigenous separations (162,993 separations) . Many of these separations involved repeat admissions for the same people, some on an almost daily basis. ICD ‘Injury, poisoning and certain other consequences of external causes’ (including motor vehicle accidents, assaults, self-inflicted harm and falls) was the next most common cause of hospitalisation for Indigenous people, responsible for 26,426 separations (7% of all separations, and 13% of separations excluding those for dialysis).
Excluding separations for pregnancy-related conditions (most of which involved normal deliveries), the next leading causes of hospitalisation for Indigenous people in 2011-12 were respiratory conditions (responsible for 21,265 separations; 11% of separations excluding those for dialysis) and digestive diseases (18,297 separations; 9% of separations excluding those for dialysis) (Table 3) .
In 2011-12, Indigenous people were hospitalised at higher rates than non-Indigenous Australians for all major causes except for neoplasms (almost entirely cancers) and diseases of the musculoskeletal system and connective tissue .
|Principal diagnosis||Number of separations||Proportion (%) of separations (excluding dialysis)||Rate ratio|
|Source: AIHW, 2013 |
|Injury, poisoning and certain other consequences of external causes||26,426||13||2.0|
|Pregnancy, childbirth and the puerperium||21,989||10.8||1.5|
|Diseases of the respiratory system||21,265||10.5||2.7|
|Diseases of the digestive system||18,297||9.0||1.0|
|Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified||17,438||8.6||1.5|
|Mental and behavioural disorders||15,009||7.4||2.1|
|Diseases of the circulatory system||6,517||5.4||1.7|
|Diseases of the genitourinary system||9,387||4.6||1.2|
|Diseases of the skin and subcutaneous tissue||7,994||3.9||2.5|
|Diseases of the musculoskeletal system and connective tissue||6,880||3.4||0.9|
|Certain infectious and parasitic diseases||5,990||2.9||1.9|
|Endocrine, nutritional and metabolic diseases||5,269||2.6||2.6|
|All causes (excluding dialysis)||203,125||100||1.3|
Potentially preventable hospitalisations are admissions which ‘could have been avoided with access to quality primary care and preventive care’ (, p.4). Rates for potentially preventable hospitalisations, including those for chronic conditions and vaccine-preventable conditions, may be used as an indirect measure of problems with access to care and effective primary care.
In the two-year period from July 2008 to June 2010, there were 87,750 potentially preventable hospitalisations of Indigenous people living in NSW, Vic, Qld, WA, SA and the NT; after age-adjustment, the Indigenous hospitalisation rate for potentially preventable admissions was 4.7 times higher than that for non-Indigenous people .
During 2008-10, rates for potentially preventable hospitalisations were higher for Indigenous people living in NSW, Vic, Qld, WA, SA and the NT than for their non-Indigenous counterparts in all age-groups . Indigenous:non-Indigenous rate ratios were particularly high for the 45-54 years and 55-64 years age-groups (9.6 and 9.3, respectively).
The most common causes of potentially preventable hospitalisations of Indigenous people living in NSW, Vic, Qld, WA, SA and the NT in 2008-10 were complications of diabetes followed by convulsions and epilepsy, and chronic obstructive pulmonary disease (Table 4) . The highest Indigenous:non-Indigenous rate ratios were for: vaccine preventable conditions (rate ratio of 4.6); potentially preventable chronic conditions (7.0); and potentially preventable acute conditions (2.4).
|Diagnosis of potentially preventable hospitalisation||Number of Indigenous admissions||Indigenous rate||Rate ratio|
|Source: AIHW, 2013 |
|Convulsions and epilepsy||6,404||7.2||5.2|
|Chronic obstructive pulmonary disease||5,675||12.5||5.0|
|Ear, nose and throat infections||4,764||3.4||2.2|
|Pyelonephritis (type of kidney disease)||4,072||6.2||2.7|
|Dehydrations and gastroenteritis||3,515||4.2||1.5|
|Congestive heart failure||2,728||6.0||3.2|