The number and proportion of NT smoking-attributable hospitalisations during the years 1998/99 and 2008/09 are presented in Table . There were 18,612 smoking-attributable hospitalisations among NT residents during the study period, accounting for nearly 4% of the 487,099 total NT public hospitalisations. There were 10,929 smoking-attributable hospitalisations among NT Aboriginal people, or 5% of the total Aboriginal hospitalisations (234,137) during the study period. Among non-Aboriginal Territorians, smoking accounted for 7,683 (3%) of 252,962 hospitalisations. Overall, more smoking-attributable hospitalisations were experienced by males (57%). Although Aboriginal people are 29% of the total NT population [8
], they experienced 59% of the total NT smoking-attributable hospitalisations.
Number and proportion of smoking-attributable hospitalisations, by sex and Indigenous status, NT 1998/99 to 2008/09
Across all years, the age-adjusted smoking-attributable hospitalisation rate in the NT Aboriginal population was 285 per 10,000 population, three times higher than the rate for non-Aboriginal people (82 per 10,000). The rate among NT Aboriginal males was 330 per 10,000 and among NT Aboriginal females, 252 per 10,000. Among NT non-Aboriginal males the age-adjusted rate was 97 per 10,000 and 62 per 10,000 among non-Aboriginal females.
Comparison of smoking attributable hospitalisation rates was made between Territorians aged under 25
years and Territorians aged 25
years and above (Table ). The younger Aboriginal population had much higher smoking-attributable hospitalisation rates than the younger non-Aboriginal population, and in each group the males and female rates were similar. By contrast, for those aged 25 and over, males in both populations had much higher rates of smoking-attributable hospitalisations than the corresponding females. Again the rates for the Aboriginal population were much higher than the corresponding non-Aboriginal population.
Age-adjusted smoking-attributable hospitalisation rates per 10,000, by sex, Indigenous status and age, NT 1998/99 to 2008/09
Figure illustrates annual age-adjusted smoking-attributable hospitalisation rates for the eleven years from 1998/99 to 2008/09. The age-adjusted smoking-attributable hospitalisation rates for Aboriginal males increased by 31% over the study period, with all of this increase occurring before 2005/06, while more recent annual rates appear to have moderated. Over the study period, the rates increased by 18% for NT Aboriginal females, and by 5% and 17% for NT non-Aboriginal males and females, respectively.
Age-adjusted smoking-attributable hospitalisation rates per 10,000, by sex and Indigenous status, NT 1998/99 to 2008/09.
The average annual increase in the smoking-attributable hospitalisation rate for Aboriginal males was 1.2% (95%CI: -5.7, 8.8) for the years from 1998/99 to 2008/09, compared to an increase of 0.8% (95%CI:-3.7, 5.5) among Aboriginal females. For non-Aboriginal males we observed a decrease in annual average smoking-attributable hospitalisation rates of 0.7% (95%CI:-7.1, 6.0). No meaningful trend was observed for non-Aboriginal females (0.0008%, 95%CI:-4.5, 4.7).
For Territorians aged under 25
years, there was a decrease in annual average smoking-attributable hospitalisation rates among both Aboriginal and non-Aboriginal people. For young Aboriginal people this decline was mainly driven by a decrease in lower respiratory disease. For non-Aboriginal Territorians aged under 25
years, the conditions behind the decline were antepartum haemorrhage, followed by asthma and otitis media. Table shows that the smallest decrease for the younger Territorians can be observed among Aboriginal females (0.4%). Among Territorians aged 25
years and over, there was an increase in annual average smoking-attributable hospitalisation rates among both Aboriginal and non-Aboriginal Territorians, with the largest increase among Aboriginal males (3.4%). There were no statistically significant trends for any of the population groups in this study (P >0.05).
Annual changes in smoking-attributable hospitalisation rates, by sex, Indigenous status and age, NT 1998/99 to 2008/09
The most common cause of smoking-attributable hospitalisations for Aboriginal Territorians was chronic obstructive pulmonary disease (COPD, 25%) followed by Ischaemic heart disease (IHD, 14.5%). For non-Aboriginal Territorians COPD (24.3%), IHD (16.2%) and low birth weight (8.3%) were the most common causes of smoking-attributable hospitalisations (Table ).
Number of smoking-attributable hospitalisations for the ten most common conditions, by Indigenous status, NT 1998/99 to 2008/09
Of the ten most common conditions the greatest increase in hospitalisations during the study period was for lung cancer, which increased more than three times among Aboriginal Territorians and by almost three times among non-Aboriginal Territorians. Among non-Aboriginal people smoking-attributable hospitalisations for asthma almost halved and also decreased for low birth weight.