Low rates of hospitalization for asthma among Aboriginal children compared to non-Aboriginal children of the Top End of the Northern Territory

Objective: To determine the hospitalization rates from asthma for Aboriginal and Torres Strait Islander (ATSI) and non-Aboriginal (non-ATSI) children in the 'top end' of the Northern Territory and to determine the proportion of hospitalizations due to asthma. Methodology: A retrospective review was undertaken of separation data from the Royal Darwin Hospital for the period July 1991 to June 1997. All children aged 1-9 years residing in the Darwin urban or rural district were included, with asthma identified by the International Classification of Diseases Version 9 codes 493.0-493.9. Results: The overall average annual hospitalization rate per 1000 population with a principal diagnosis of asthma for ATSI children from rural areas (ATSI-rural) was 2.6, 4.7 for ATSI children from urban areas (ATSI-urban) and 5.5 for non-ATSI children. These hospitalization rates were significantly different between ATSI and non-ATSl children (rate ratio 0.72, 95% CI 0.59-0.86). On stratification for residence, the rates were significantly different between ATSI-rural and non-ATSI children (rate ratio 0.61, 95% CI 0.47-0.80) but not different between rural and urban dwelling ATSI children (rate ratio 0.76, 95% CI 0.54-1.07) or between ATSI-urban children and non-ATSI children (rate ratio 0.81, 95% CI 0.63-1.03). Asthma was diagnosed in 6.5% of ATSI admissions (4.0% for ATSI-rural and 13.8% for ATSI-urban) and 12.7% of non-ATSI admissions. Conclusions: The hospitalization rate for ATSI children with asthma was significantly lower than for non-ATSI children. Asthma plays a far less significant role in the spectrum of disease affecting hospitalized ATSI children compared to non-ATSI children. There are significant differences in disease frequency between urban and rural resident ATSI children but less marked differences between urban resident ATSI children and non-ATSI children. Further study is required ii the underlying causes behind these differences are to be determined.