Hospital separations data for the Aboriginal and non-Aboriginal usual resident populations of the East Kimberley were obtained for the years 1991 to 2001. Also obtained were principal diagnosis data for all separations coded by ICD9 and ICD10. However, because the data were acquired by calendar year, ICD9 data are anlaysed only for the period 1991 to 1998, and ICD10 data for 2000 and 2001. These data, provided at unit record level, form the basis for compiling a statistical profile of the health status of the regional population. However, because the focus is inevitably on diagnoses of major morbidity (i.e. conditions serious enough to warrant hospitalisation), the data do not provide a full measure of the burden of ill health in the region. An indication of this is provided by analysing clinic-derived data from KAMSC and KHS.

Before considering hospitalisation data in detail, it is important to note that the number of admissions far exceeds the number of individuals admitted. This is obviously because many people are admitted more than once. Among Aboriginal residents of the East Kimberley, for example, a total of 30,908 hospital separations were recorded between 1991 and 2001. However, these separations were generated cumulatively by just 16,547 individuals producing an average of 1.9 separations per patient. The equivalent ratio for non-Aboriginal residents of the East Kimberley over the same period was 1.02 separations per patient, making the Aboriginal ratio twice as high. This gap has remained reasonably stable since 1991, although there has been a slight rise in the ratio of Aboriginal separations to patients, from 1.7 in 1991 to 2.0 in 2001. However, it is difficult to interpret this rise in the ratio of separations to patients as it may reflect a number of factors: that people are now more sick and therefore require more treatment; that access to the hospital system has improved; or that local health staff are now more inclined to refer cases to hospital. Which of these holds true has not been determined.

An indication of the age pattern of hospital admissions is provided in Table 7.5, which shows the hospital separation rate for Aboriginal and non-Aboriginal males and females in the East Kimberley by five-year age group for the period 2000-01 using the 2001 ERP as a denominator. Figure 7.1 illustrates the pattern separately for Aboriginal males and females. Several stages of morbidity are apparent based on prevailing rates at different ages. First, high rates of hospitalisation are evident among both male and female infants aged 0-4 years, especially among Aboriginal infants as indicated by the relatively high rate ratios. Separation rates then fall away gradually up to the age group 20-24 for Aboriginal males, and 15-19 for females owing to relatively high levels of teenage pregnancy. Beyond the age of 30 years hospitalisation rates for Aboriginal males and females are high, both absolutely and relative to their non-Aboriginal counterparts despite a tendency for all rates to increase with advancing age. In the oldest age groups over 60 years, Aboriginal rates are exceedingly high for both males and females owing largely to high demand for renal dialysis.