Place in health.

Abstract

This research contributes to expanding the awareness and importance of place in health research. As a thesis by publication it features three peer reviewed published papers which provide methodological developments for the application of spatial techniques to health research. These papers constitute a response to the critique by a number of researchers on how spatial techniques are applied in some health research. Place has been implicated in health research for centuries. Among the place-health literature there are two research streams that are the focus of this thesis; 1) the relationship between place and socioeconomic status (SES); and 2) the impact of the built environment on physical activity and chronic disease. Place has an association with SES and SES has an accepted relationship with health, and therefore place may impact on health through its relationship with SES. An emerging research area used property values to represent wealth as an alternative or complementary SES measure. Two recent studies have used property value as an SES measure and reported a strong association with obesity and reported that property value was more predictive of fair/poor health status than area-level SES measures. This emerging research area is the focus of the first two papers which developed a property value SES measure that reflected place and wealth. The first paper provided the methodology to develop a residential property value measure (RLF) and the second paper tested the association between RLF and six chronic health outcomes, central obesity, hypertriglyceridemia, reduced high density lipoprotein (HDL), hypertension, impaired fasting glucose, and high low density lipoprotein (LDL) plus cumulative score of these chronic health outcomes. A statistically significant association with the cumulative CMR score and all but one of the risk factors (high LDL) was found, and in all cases except high LDL, participants in the most advantaged and intermediate group had a lower relative risk (RR) for cardio-metabolic diseases. The third paper focused upon the built environment and walkability and the methodology used to spatially represent walkability. Whilst this paper used the Australian adaptation of the walkability index used for the IPEN project (www.ipenproject.org), the outcome was not walking behaviour but the cumulative cardiometabolic risk score used in paper two. The third paper used predetermined administrative spatial units and road network buffers. This approach was chosen to provide further evidence that the choice of spatial unit matters in health research and that selecting an inappropriate spatial unit could mask or hide an association. There was no statistically significant association between walkability and the predetermined spatial units, but there was a modest statistically significant association between the road network buffers and lower RR of cardiometabolic risk. Taken individually, the first two papers provide a spatially based measure for SES-health research which was statistically associated with chronic health outcomes and the third added to the literature on health associations with walkability and highlighted the need for appropriate spatial unit selection. Cumulatively, these papers add to the growing literature and demonstrated a more informed application of spatial methods to health research.