Date Published: September 30, 2015
Publisher: Public Library of Science
Author(s): Lina Gubhaju, Emily Banks, Rona MacNiven, Bridgette J. McNamara, Grace Joshy, Adrian Bauman, Sandra J. Eades, Hamid Reza Baradaran.
Australian Aboriginal people are disproportionately affected by physical disability; the reasons for this are unclear. This study aimed to quantify associations between severe physical functional limitations and socio-demographic and health-related factors among older Aboriginal and non-Aboriginal adults.
Questionnaire data from 1,563 Aboriginal and 226,802 non-Aboriginal participants aged ≥45 years from the Sax Institute’s 45 and Up Study (New South Wales, Australia) were used to calculate age- and sex-adjusted prevalence ratios (aPRs) for severe limitation [MOS-PF score <60] according to socio-demographic and health-related factors. Overall, 26% (410/1563) of Aboriginal participants and 13% (29,569/226,802) of non-Aboriginal participants had severe limitations (aPR 2.8, 95%CI 2.5–3.0). In both Aboriginal and non-Aboriginal participants, severe limitation was significantly associated with: being ≥70 vs <70 years old (aPRs 1.8, 1.3–2.4 and 5.3, 5.0–5.5, within Aboriginal and non-Aboriginal participants, respectively), none vs tertiary educational qualifications (aPRs 2.4, 1.7–3.3 and 3.1, 3.0–3.2), lower vs higher income (aPRs 6.6, 4.2–10.5 and 5.5, 5.2–5.8), current vs never-smoking (aPRs 2.0, 1.6–2.5 and 2.2, 2.1–2.3), obese vs normal weight (aPRs 1.7, 1.3–2.2 and 2.7, 2.7–2.8) and sitting for ≥7 vs <7 hours/day (aPRs 1.6, 1.2–2.0 and 1.6, 1.6–1.7). Severe limitations increased with increasing ill-health, with aPRs rising to 5–6 for ≥5 versus no chronic conditions. It was significantly higher in those with few vs many social contacts (aPRs 1.7, 1.4–2.0 and 1.4, 1.4–1.4) and with very high vs low psychological distress (aPRs 4.4, 3.6–5.4 and 5.7, 5.5–5.9). Although the prevalence of severe physical limitation among Aboriginal people in this study is around three-fold that of non-Aboriginal people, the factors related to it are similar, indicating that Aboriginal people have higher levels of risk factors for and consequences of severe limitations. Effective management of chronic disease and reducing the prevalence of obesity and smoking are important areas for attention.
Australian Aboriginal adults have an average life expectancy approximately 10 years less than non-Aboriginal Australians  and have greater levels of ill-health at all stages of life. Colonisation of Australia has had a profound influence on the social, emotional and physical health of Australian Aboriginal people. It is likely that the consequent disempowerment and dramatic shift in diet and lifestyle have played a major role in the deteriorating physical and emotional wellbeing of generations of Aboriginal people .
The study population available for analyses included 1563 Aboriginal and 226802 non-Aboriginal participants. Baseline socio-demographic and health characteristics of these participants are given in Table 1. The proportion of participants in the younger age groups was higher among Aboriginal people compared to non-Aboriginal people.
The prevalence of severe limitation among middle-aged and older Aboriginal people in this study was approximately three times that of non-Aboriginal people, such that over one-quarter of Aboriginal participants had severe physical limitations. Among both Aboriginal and non-Aboriginal participants, severe limitation was associated with older age, socio-economic disadvantage, being a former or current smoker, obesity, sedentary behaviour (screen time and sitting time), poor self-rated health and quality of life, high psychological distress and fewer social contacts. Prevalence of severe limitation also increased steadily with increasing number of chronic conditions. Although Aboriginal people had a consistently higher absolute prevalence of severe limitation, in general the factors relating to severe limitation were similar for Aboriginal and non-Aboriginal participants. This suggests that Aboriginal people may not have differential vulnerability to physical functional limitations, but experience a higher prevalence of the factors that are related to higher levels of physical disability in the population as a whole.
Aboriginal people in the 45 and Up Study have a significantly greater burden from physical functional limitations compared to non-Aboriginal people. The relationships of socio-economic, health and psychosocial factors to severe limitation among Aboriginal and non-Aboriginal people were very similar. Taken together, these indicate that Aboriginal people have greater levels of risk factors for and consequences of severe physical limitation, and these occur at younger ages. The major role of ill health in disability highlights the importance of continuing efforts in chronic disease management and the need to address the smoking and obesity epidemics.