Measuring BMI in an Aboriginal population survey: who are the non-responders?

Abstract

Objective To describe the characteristics of South Australian Aboriginal respondents reporting unhealthy weight, as well as those not knowing their height or weight. Methods Trained Aboriginal interviewers undertook 399 face-to-face interviews with Aboriginal people 15 years and over from randomly selected dwellings, in metropolitan, rural and remote areas of South Australia (response rate: 57.7%). Questions were included to determine prevalence of unhealthy weight in this representative population. Results Self-reported prevalence of unhealthy weight was n= 79/106, (74.5% 95% CI 65.1-81.6), and these respondents were more likely to have diabetes, high blood pressure, or had lived in their residence for more than 6 months; and less likely to have asthma, or experience food insecurity, than those who were underweight or normal weight. Those who did not know their height and weight (n= 247/353, 70.1%, 95% CI 65.0–74.5), were more likely to be unemployed, undertake home duties, or be retired or unable to work; and less likely to live in rural or remote South Australia, be aged 45 years and over, or have a mental health condition that those who had answered the height and weight questions. Conclusions Unhealthy weight in the Aboriginal population exceeds general population levels. The main limitation to assessing accurate levels of unhealthy weight was that a large proportion of Aboriginal people in this study did not know their height and weight. Limited access to primary health care, the social undesirability of reporting increased weight, or the conflict of health and lifestyle priorities, may explain this. Implications Identification of the characteristics of this population are important; strategies may be defined to prevent non-response in similar surveys. These data are a powerful resource informing policy and future research involving the social determinants of Aboriginal health.