Notes on the data: Aboriginal mothers and babies

Aboriginal women who reported smoking at any time during pregnancy, 2017 to 2019

Policy context: Tobacco smoking during pregnancy is the most common preventable risk factor for pregnancy complications [1]. Smoking during pregnancy is associated with poorer perinatal outcomes including low birthweight, being small for gestational age, pre-term birth and perinatal death [3]. Indigenous Australians are more than twice as likely as non-Indigenous Australians to be current daily smokers (after adjusting for differences in age structure between populations) [2].

Over half of Indigenous mothers reported smoking during pregnancy (50.9%), compared with 14.4% of pregnant non-Indigenous women [2]. Smoking rates for Indigenous mothers varied by region and age, with highest rates for those living in Outer Regional (56.0%) areas and lowest for those living in Major Cities (49.3%) [1]. Smoking rates were highest among younger Indigenous mothers, with 53.6% of those aged under 20 years smoking during pregnancy [2]. Proportions of women smoking during pregnancy gradually decline with increasing age [2].

In New South Wales, Aboriginal and Torres Strait Islander mothers smoked during pregnancy at around four times the rate of non-Indigenous mothers. In Western Australia, South Australia and the Australian Capital Territory, Indigenous mothers smoked at three times the rate of non-Indigenous mothers. Indigenous mothers in the Northern Territory smoked during pregnancy at twice the rate of non-Indigenous mothers [3].

References

Australian Institute of Health and Welfare 2015. Australia’s mothers and babies 2013—in brief. Perinatal statistics series no. 31. Cat no. PER 72. Canberra: AIHW.
Australian Institute of Health and Welfare 2011. Substance use among Aboriginal and Torres Strait Islander people. Cat. no. IHW 40. Canberra: AIHW.
AIHW (Australian Institute of Health and Welfare): Laws PJ & Sullivan EA 2004. Report on the Evaluation of the Perinatal National Minimum Data Set. Perinatal Statistics Series no. 14. AIHW cat. no. PER 27. Sydney: AIHW National Perinatal Statistics Unit.

Notes: Data published previous to 2015 to 2017 were collected from each State and Territory health agency and are likely to have excluded people who live in one State/Territory and used a service in another. This data release uses data, provided to the Australian Institute of Health and Welfare by each State and Territory, in which residents of another jurisdiction were generally coded to their correct usual address. This change will affect the time series published for quintiles and Remoteness Areas.

As the data are aggregated over three years, they may include women who gave birth more than once during the time period. Data for many remote areas, particularly in Western Australia and Northern Territory, should be treated with caution as the quality of the population correspondence provided by the Australian Bureau of Statistics is rated as ‘Poor’.

Data quality

As is the case in most statistical collections in Australia, Indigenous status is under-reported in the midwives data collections from which these data are compiled. However, the level of completeness of coverage (the extent to which the identification of Indigenous Australians occurs in data collections) in these collections is generally higher than in the deaths or hospital inpatient data collections. It should also be noted that coverage is likely to vary between geographical areas.

Geography: Data available by Indigenous Area, Primary Health Network, Quintile of socioeconomic outcomes (based on IRSEO) and Remoteness Area

Numerator: Aboriginal women who reported that they smoked at any time during their pregnancy (data over 3 years)

Denominator: Number of Aboriginal women who gave birth (data over 3 years)

Detail of analysis: Per cent

Source: Compiled by PHIDU based on data from the Australian Institute of Health and Welfare, on behalf of the States and Territories.