In profiling the nature of morbidity as defined by principal disease diagnosis, data for all hospital separations (including repeat separations) are utilised. This is because individuals can, and often are, admitted to hospital more than once, but for quite different reasons. Table 7.6 shows the distribution of separations by ICD10 category for male and female Aboriginal residents of the East Kimberley over the period 2000-2001. More than 6,000 such separations were recorded over this two-year period, 56% of them due to females. Over the 10-year period between 1991 and 2001 the total number of Aboriginal separations amounted to 30,908 suggesting a fairly stable average of around 3,000 separations per annum. In 2001, this represented an annual separation rate of around 500 per 1,000.
The first point to note is the quite distinct difference between male and female causes of hospitalisation. Almost one-fifth of separations among females were classified as complications of pregnancy and childbirth, although 14% of these involved normal spontaneous deliveries. While this somewhat distorts comparison, it is apparent that males and females share a similar morbidity profile. Thus, infectious disease, diseases of the circulatory system, skin diseases, injury and poisoning, and dialysis are common reasons for hospital admission among both sexes. At the same time, different conditions appear to be more prevalent among males (diseases of the nervous system, the respiratory system, skin diseases and injury and poisoning), and among females (diseases of the genitourinary system).
Table 7.6. Hospital separations by cause: Aboriginal residents of the East Kimberley, 2000–2001
 |
Separations |
Proportion of separations |
||
|
ICD10 disease chapter |
Males (no.) |
Females (no.) |
Males (%) |
Females (%) |
|
Infectious |
156 |
184 |
5.9 |
5.4 |
|
Neoplasms |
34 |
38 |
1.3 |
1.1 |
|
Endocrine/nutritional |
7 |
23 |
0.3 |
0.7 |
|
Blood and related organs |
43 |
73 |
1.6 |
2.1 |
|
Mental disorders |
109 |
101 |
4.1 |
3.0 |
|
Nervous system |
118 |
47 |
4.4 |
1.4 |
|
Eye and adnexa |
40 |
22 |
1.5 |
0.6 |
|
Ear and mastoid process |
49 |
51 |
1.8 |
1.5 |
|
Circulatory system |
124 |
118 |
4.7 |
3.5 |
|
Respiratory system |
376 |
403 |
14.2 |
11.8 |
|
Digestive system |
143 |
138 |
5.4 |
4.0 |
|
Skin |
162 |
124 |
6.1 |
3.6 |
|
Musculoskeletal system |
63 |
72 |
2.4 |
2.1 |
|
Genitourinary system |
47 |
144 |
1.8 |
4.2 |
|
Pregnancy, childbirth |
0 |
673 |
0.0 |
19.7 |
|
Perinatal conditions |
34 |
43 |
1.3 |
1.3 |
|
Congenital malformations |
16 |
5 |
0.6 |
0.1 |
|
Symptoms n.e.c. |
144 |
181 |
5.4 |
5.3 |
|
Injury and poisoning |
467 |
451 |
17.6 |
13.2 |
|
Health service contact |
524 |
517 |
19.7 |
15.2 |
|
Total (excluding dialysis) |
2,248 |
3,053 |
84.6 |
89.6 |
|
Total (including dialysis) |
2,656 |
3,408 |
100.0 |
100.0 |
These contrasts and similarities between male and female morbidity are made clearer in Figure 7.2 using ICD9 data for the period 1991–1998 with female separations for complications of pregnancy and childbirth (ICD9 Chapter X1) omitted. Comparison with the morbidity profile of male and female non-Aboriginal residents of the region is provided in Figure 7.3. The non-Aboriginal morbidity profile is broadly equivalent with injury and poisoning, diseases of the respiratory and circulatory systems, and factors influencing contact with health services looming large, but clear contrasts also exist. For example, diseases of the respiratory system are far more prominent among Aboriginal males and females, as are infectious diseases, while Aboriginal females are far more likely to be hospitalised for diseases of the nervous system, and for injury and poisoning than are their non-Aboriginal counterparts.
Figure 7.2. Male and female Aboriginal hospital separations by ICD9 chapter: a East Kimberley, 1991–1998
Figure 7.3. Male and female non-Aboriginal hospital separations by ICD9 chapter: East Kimberley, 1991–1998
Note: a. Excludes Chapter 11: complications of pregnancy and childbirth
Key to Figures 7.2 and 7.3:
1. Infectious and parasitic diseases. 2. Neoplasms. 3. Endocrine, nutritional and metabolic disease and immunity disorders. 4. Diseases of the blood and blood-forming organs; 5. Mental disorders. 6. Diseases of the nervous system and sense organs. 7. Diseases of the circulatory system. 8. Diseases of the respiratory system. 9. Diseases of the Digestive system. 10. Diseases of the genitourinary system. 11. Complications of pregnancy and childbirth. 12. Diseases of the skin. 13. Diseases of the musculoskeletal system. 14. Congenital anomalies. 15. Conditions originating in the perinatal period. 16. Symptoms, signs and ill-defined conditions. 17. Injury and poisoning. 18. Supplementary classification of factors influencing health status and contact with health services.
Watson, Ejueyitsi and Codde (2001) have calculated standardised separation rates for the five leading causes of Aboriginal death in Western Australia. As with the relative death rates shown earlier, these are presented in Table 7.7 for the East and West Kimberley and the State average. This shows that the age-standardised Aboriginal morbidity rate is markedly higher in the East Kimberley for circulatory diseases, respiratory diseases, and injury and poisoning compared to those recorded in the West Kimberley and Western Australia as a whole. However, as was the case with relative death rates, the rate ratio with non-Aboriginal morbidity is highest in the East Kimberley across all the disease categories.
Once again an aetiological fraction methodology can be applied to hospital separations data to estimate the proportion of illnesses and injuries attributable to alcohol consumption (Unwin et al. 1997). These are shown in Table 7.8 using all separations from the East Kimberley for the period 1993-1995. Overall, one-third of alcohol-related separations were manifest as diseases, mostly alcoholism, while most such separations presented as injuries due largely to assault. Of related interest is the length of time spent in hospital as a consequence, together with the share of the cost of hospital care due to alcohol-related conditions. According to Unwin et al. (1997), the average cost of alcohol-caused hospitalisation in the East Kimberley in 1993-95 was $402,747 equivalent to $46 per capita. This was much higher than the state average of only $15 per head, and slightly above the West Kimberley figure of $44, making the average cost of alcohol-related hospitalisation in the East Kimberley the highest for any health service area in Western Australia at that time. As shown in Table 7.8, much of this cost burden was due to assaults and alcoholism.
Table 7.7. Standardised hospital separation rates for select ICD9 categories by Western Australian health service region of residence, 1990–1999
|
East Kimberley |
West Kimberley |
Western Australia |
|
Circulatory diseases |
|||
|
Age standardised rate |
44.2 |
36.3 |
41.3 |
|
Rate ratio |
6.0 |
2.2 |
2.2 |
|
Neoplasms |
|||
|
Age standardised rate |
8.2 |
10.6 |
10.6 |
|
Rate ratio |
1.7 |
0.7 |
0.6 |
|
Respiratory diseases |
|||
|
Age standardised rate |
101.8 |
91.6 |
82.7 |
|
Rate ratio |
6.4 |
3.7 |
5.2 |
|
Injury and poisoning |
|||
|
Age standardised rate |
96.8 |
81.9 |
69.6 |
|
Rate ratio |
4.3 |
2.7 |
3.6 |
|
Diabetes |
|||
|
Age standardised rate |
10.6 |
12.2 |
13.2 |
|
Rate ratio |
21.2 |
11.1 |
12.0 |
|
Source: Watson, Ejueyitsi, and Codde 2001 |
|||
Table 7.8. Hospital separations due to alcohol-related conditions: Total population of the East Kimberley, 1993–1995
|
Alcohol-related conditions |
No. of hospital admissions |
Average length of stay (days) |
% of alcohol-caused cost |
|
Liver cirrhosis |
17 |
5.4 |
3.3 |
|
Alcoholism |
160 |
3.0 |
17.3 |
|
Cancers |
0 |
0 |
0.0 |
|
Stroke |
7 |
10.3 |
2.6 |
|
Other related diseases |
68 |
3.0 |
7.5 |
|
Road injuries |
61 |
5.2 |
11.5 |
|
Falls |
70 |
4.4 |
11.1 |
|
Suicide |
6 |
3.3 |
0.7 |
|
Assaults |
314 |
3.3 |
38.3 |
|
Other related injuries |
26 |
8.2 |
7.7 |
|
Total |
729 |
3.8 |
100.0 |
|
Source: Unwin et al. 1997 |
|||
Unfortunately, the Unwin et al. study does not differentiate Aboriginal from non-Aboriginal separations. To provide some measure of the differential impact of alcohol on morbidity among East Kimberley residents, an assessment of alcohol-related conditions by Aboriginality was extracted from the separations data obtained from the WA Department of Health over the longer period from 1991-1998, although with reference only to the 17 primary chapters of ICD9 and therefore excluding the supplementary classification of external causes of injury and poisoning. Over this period, a total of 1,265 diagnosed hospital separations due to alcohol-related conditions were recorded among Aboriginal residents of the East Kimberley comprising 5.5% of all Aboriginal separations. The equivalent figures for non-Aboriginal residents were 243 and 3.3%.