Understanding the relationships between culture, associated health beliefs and lifestyle, and ethnic disparities in health is of particular importance in Australia, where one in four people was born overseas. Vietnam-born Australians (N=159,849 at the 2006 Census) are among the top five overseas-born population groups. Most arrived as refugees (50%, 1977-1986) and family reunion immigrants (42%, 1987-1996), thus many have poorer socio-economic status than other population groups. Vietnam-born Australians also share a distinct Oriental culture and traditional health beliefs that largely differ from Western biomedicine perspectives. Changes in diet among new immigrants have been reported but the impact of acculturation on various lifestyle factors and, importantly, health status of Vietnam-born Australians has not been examined extensively. Research evidence shows that people of Vietnamese ethnicity are at higher risk of diabetes. However, there is little existing information about diabetes among Vietnam-born Australians. Therefore, this thesis aimed to investigate two interrelated aspects of health in this population: the impact of acculturation on health-related behaviours and health status; and the prevalence of type 2 diabetes, its risk factors and hospitalisation and mortality outcomes. Baseline questionnaire data (2006 to 2008) from the 45 and Up Study, a cohort study of more than 266,000 residents of New South Wales (NSW), Australia aged 45 years and over, were used to investigate relationships between acculturation (duration of residence, age at immigration, density of Vietnam-born population in residential areas, and social interactions) and lifestyle, health status, and prevalence of and risk factors for type 2 diabetes. Analytic techniques included descriptive statistics, direct age-standardisation and logistic regression modelling. Among 797 Vietnam-born participants in the Study (390 men and 407 women), higher levels of acculturation were associated with increased consumption of red meat, white meat and seafood, higher levels of physical activities, and lower prevalence of overweight and obesity, and type 2 diabetes. Likelihood of smoking was lower among Vietnam-born men living in areas with low proportion of Vietnam-born population (< 2%). The age standardised prevalence of self-reported type 2 diabetes was 11.2% (crude prevalence 12.9%), which was 1.6 times (95%CI=1.31-1.90) higher than in Australia-born participants. Strong risk factors for type 2 diabetes in Vietnam-born participants included family history of diabetes (adjusted odds ratio [OR]=7.07, 95%CI=4.14-12.07) and older age (OR≥2.49, p< 0.001). Overweight or obesity based on body mass index (≥23.0 kg/m2) was not a strong predictor (OR=1.64, 95%CI=0.99-2.74). Vietnam-born people with type 2 diabetes were more likely to have a health care concession card, high blood pressure, heart disease, and poorer self-rated general health and quality of life. The NSW Admitted Patient Data Collection (APDC, 1/7/2000 to 31/12/2008), an administrative database of all hospital stays in NSW, was linked to NSW death registrations (1/7/2000 to 30/12/2009) and Australian Bureau of Statistics mortality data (1/7/2000 to 30/12/2007) to investigate diabetes-related hospitalisation and mortality. One hundred and fifty-two Vietnam-born patients admitted between 1/7/2000 and 31/12/2008 for treatment of type 2 diabetes were followed prospectively for readmissions and mortality. Statistical techniques included Poisson and Cox proportional hazard regression modelling. Vietnam-born patients had lower rates of readmission for diabetes and comorbidities (450.7, 95%CI=394.4-515.0 per 1,000 person-years) than Australia-born counterparts (528.5, 95%CI=522.2-535.0) but the difference was not statistically significant (adjusted rate ratio [RR]=0.81, 95%CI=0.64-1.03). However, Vietnam-born patients had significantly higher risk of death from all causes (adjusted hazard ratio [HR]=1.42, 95%CI=1.07-1.88) and for diabetes-related causes (HR=1.58, 95%CI=1.05-2.38). The prevalence of hypertension, chronic kidney disease, and other comorbidities was significantly higher in Vietnam-born than in Australia-born patients. The findings of this thesis have implications for education about healthy lifestyle and for proactive management of diabetes in this population. Early diagnosis and optimal control of diabetes and comorbid conditions are important for Vietnam-born Australians given their high risk of diabetes. Family members' participation in patient-centred management of people with diabetes could provide additional positive outcomes. This research has demonstrated the value of record linkage of already available, population-based health administrative data for investigating diabetes management and associated health outcomes among overseas-born Australians.
| Date of Award | 2013 |
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| Original language | English |
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