Simulation and analysis of the effect of environmental interventions on physical activity & obesity: international study

The ongoing discussion in public health about the relative importance of ‘place‘ in determining health risks has been the focus of significant debate in recent years. Moreover, as obesity and type 2 diabetes become increasingly prevalent in wealthy countries, the role of environmental and neighbourhood interventions in policy development needs to be rigorously evaluated to identify the most effective programmes with which to improve health. The proposed project is cost-effective, making use of existing datasets and an established methodology to conduct a series of assessments of the likely health impact of neighbourhood and environmental interventions. The project uses simulation models as one way of ‘testing‘ the effectiveness of proposed environmental interventions on physical activity and obesity. For example, does changing the design of urban neighbourhoods to make them more densely populated and walkable impact on physical activity and thus reduce the prevalence of obesity. The project is a collaborative, international study providing the opportunity to test the utility of simulation models to firstly estimate the health of a selection of neighbourhoods in London, UK and Perth, Australia and secondly to model and then validate the impact on health of a range of environmental interventions.

Aims & Objectives: Research concludes that neighbourhood environments have a measurable effect on residents‘ physical activity and obesity. Policymakers‘ responses to these findings have been to suggest neighbourhood level intervention programmes addressing selected neighbourhood characteristics such as area deprivation, access to health-promoting resources and urban design. At the present time there is limited data on the actual effects of environmental interventions. This project aims to test the accuracy and effectiveness of population simulation in order to assess the impact of plausible neighbourhood interventions on the physical activity and obesity of residents in London, UK and Perth, Australia.

Design & Methodology: The proposed project will simulate the public health effects of neighbourhood environmental interventions in two study areas through the use of two pre-existing datasets. From the UK, the applicant will use Research with East London Adolescents: Community Health Survey (RELACHS), a three-phase longitudinal study of 2,800 adolescents from East London with surveys in 2001, 2003 and 2005. From Australia, the applicant will use RESIDential Environments (RESIDE), a five-year longitudinal study based in Perth tracking participants‘ physical activity levels, height and weight. RESIDE began in 2003 and includes 1,813 adults moving into new housing estates. Firstly, the neighbourhood-level predictors of physical activity and related health outcomes will be identified in each study area through analysis of the datasets. Then additional data such as mental wellbeing will be linked to each dataset using sociodemographic attributes. Following data linkage, baseline population health profiles (including individual height and weight, dietary and physical activity habits, smoking and mental health) within each of the two surveys will be estimated and compared to the available data. This will validate the model estimates and provide greater confidence in the final simulations of environmental interventions in both settings. These simulations can predict the relative effectiveness of different intervention schemes in each country without relying on costly and time-consuming pilot programmes.

Scientific Outcomes: This will be the first study to systematically evaluate simulated small-area population health estimates and simulate health impacts of environmental interventions using real-world longitudinal datasets. Equally novel is the international scale of the study, which will test the reliability of public health simulation modelling in contrasting settings.