Information on the health status of Aboriginal people is collected as a matter of course in the day-to-day operation of the health care system in the East Kimberley. Couzos and Murray (1999) have summarised the scope, content and quality of health information available for the Kimberley region as a whole, concluding that the implementation of an evidence-based approach to primary health care, including the use of information technology, provides the key to successful health care delivery for the region. At the same time, public access to primary health care data is limited. Thus, while the Ferret data base of the Kimberley Aboriginal Medical Services Council (KAMSC) provides some basis for describing disease prevalences,[6] and while data on Aboriginal birth weights are available from the Kimberley Health Services (KHS), the most comprehensive set of data regarding Aboriginal morbidity, and that which is mostly utilised here, is hospital separations data provided by the WA Department of Health.
Western Australia was the first jurisdiction to include an Indigenous identifier in its hospital statistics. These data are coded to SLA of usual residence and information on the number and diagnosis of hospital separations can therefore be compiled for the East Kimberley region as a whole, though not for the study region.
As is the case with many social indicators, this need for a regional aggregation of statistics is recognised by the Kimberley Regional Aboriginal Health Plan (Atkinson, Bridge and Gray 1999: 36) as an essential requirement for the production of statistically reliable health indicators, given the relatively small size of the populations within the region. While this inevitably involves some loss of geographic detail, it nonetheless enables the compilation of detailed statistics of major morbidity for Aboriginal and non-Aboriginal individuals who indicate the East Kimberley as their usual place of residence. Importantly, in the context of establishing a baseline regional health profile, it also enables the calculation of age-specific rates of hospitalisation, with the proviso that ABS estimated resident population figures and hospital admissions data are assumed to be sufficiently compatible for the former to be employed as a meaningful denominator.
Also available using hospital statistics are comparative data on Aboriginal and non-Aboriginal health status between the East Kimberley and health service regions in the rest of Western Australia. These data, compiled by the Western Australian Department of Health using hospital separations for the period 1994-2000, detail the comparative rates of five conditions that account for 75% of all Aboriginal deaths in Western Australia as a whole—circulatory disease, cancer, respiratory disease, injury and poisoning, and diabetes (Watson, Ejueyitsi, and Codde 2001). As for self-assessed health status, some indication of this is available for the Wunan Regional Council area compared to other regional council areas via the 1994 National Aboriginal and Torres Strait Islander Survey (NATSIS).
The level of mortality provides a proxy measure of health status. While the usual residence of Aboriginal people is recorded in death statistics held by the ABS these are coded only to the SLA level. Thus, in the two SLAs that make up the East Kimberley a total of 502 Aboriginal deaths were recorded between 1991 and 2001—an average of 50 deaths per annum, although the greatest annual number of deaths (61) occurred at the beginning of this period in 1991, and the lowest (36) occurred at the end of the period in 2001, suggesting a decline in death rates over the decade. With these figures of annual deaths, it is possible to calculate a standardised Aboriginal mortality rate for the East Kimberley to account for the quite different age structure of the Aboriginal population and the effect that this might have on the Aboriginal rate compared to the non-Aboriginal rate. Given the relatively small size of the regional Aboriginal population, it is appropriate to apply the indirect method for establishing this (ABS 2002b: 107). This is calculated by applying published age- and sex-specific death rates for the total Australian population (ABS 2002b: 50) to the 2001 regional Aboriginal ERP age/sex distribution. An annual figure for deaths in the East Kimberley is then estimated by averaging recorded deaths over the period 1996-2001 to account for annual variation. This observed figure of 43 Aboriginal deaths for the region is then compared to the expected number (18) derived from the application of the standard age-specific death rates. This produces a standardised mortality ratio for the Aboriginal population of 2.4 indicating that there are more than twice as many Aboriginal deaths in the region than would be expected if the mortality profile observed for the total Australian population applied.
In terms of an indirectly standardised Aboriginal death rate for the East Kimberley, this translates into 15.8 deaths per 1,000 which is somewhat higher than the equivalent indirect rate of 13.4 deaths per 1,000 calculated for Indigenous people in Western Australia as a whole (Table 7.1). However, it is significant to note that almost all of this difference is accounted for by the fact that the adjusted death rate for Aboriginal women in the East Kimberley is 60% higher than that recorded for all Indigenous women in Western Australia. Compared to the total non-Indigenous population of Western Australia, overall Aboriginal death rates in the East Kimberley are three times higher. The comparable figure for all Indigenous people in Western Australia is 2.6 times higher. It is not surprising, then, to discover that the median age at death for Aboriginal people in the East Kimberley between 1997 and 2001 was 47 years compared to 53 years for Indigenous people generally in Western Australia, and 78 years for non-Indigenous people (ABS 2002b: 79-80).
Table 7.1. Indigenous and non-Indigenous indirect standardised death ratesa for the East Kimberley and Western Australia, 2001
|
Male |
Female |
Total |
|
 |
|||
|
Indigenous East Kimberley |
17.1 |
14.7 |
15.8 |
|
Indigenous WA |
18.3 |
9.2 |
13.4 |
|
Non-Indigenous WA |
N/Ab |
N/Ab |
5.2 |
|
Notes: a. Per 1,000 b. N/A = not applicable Source:Calculated from ABS Deaths registration data, and information in ABS (2002: 35, 86) |
|||
[6] Such data were forthcoming from the Ord Valley Aboriginal Health Service in Kununurra, but not from the Yuri Yangi Medical Service in Halls Creek.