New ways of measuring the supportiveness of environments for physical activity. Andy Jones School of Environmental Sciences, University of East Anglia, and Centre for Diet and Activity Research (CEDAR) 24 th January 2012

The social ecological model of health.

The concept of ‘Obesogenic Environments’ Developed as a research field since early 1990’s

Evidence limitations we identified in the Foresight review Many studies make assumptions concerning environmental exposures. Use of features of the environment for physical activity is often not measured. Measures of physical activity are not environment-specific. Most studies have an urban focus.

Global Positioning Systems A way of overcoming these limitations GPS Satellite GPS Receiver

Modern GPS are small and unobtrusive

SPEEDY GPS

Software development

SPEEDY GPS. Showed the importance of urban greenspaces.

SPEEDY GPS And that children undertook unstructured play in the countryside.

A research methodology that is growing in importance Identified 24 published studies using GPS

Case study Are the overheads of collecting GPS data justified?

Does neighbourhood greenness reflect use of greenspace for children’s physical activity?

Research questions Is there an association between neighbourhood greenness and overall levels of moderate-vigorous physical activity (MVPA) in children? Do children who live in greener neighbourhoods actually use greenspace? How much might any ‘green’ MVPA contribute to their overall levels?

Study design Study uses data on year old children participating in the PEACH project. Children lived in Bristol. Five days of accellerometery and GPS were collected between November 2007 and July 2009 – 10,000 person hours of data. Land uses were mapped and greenspaces were identified with the help of data from Bristol City Council. The data sources were overlaid in a Geographical Information System (GIS) to examine use of greenspaces.

Sample of the data

Associations between minutes of overall MVPA and neighbourhood greenness Values given are rate ratios of adjusted means

Associations between neighbourhood greenness and time spent in greenspace Values given are rate ratios of adjusted mean minutes.

Associations between neighbourhood greenness and MVPA undertaken in greenspace Values given are rate ratios of adjusted mean minutes.

Conclusions Amongst the PEACH cohort, children who lived in greener neighbourhoods did not record more MVPA overall. But the GPS told us that they spent more time in greenspaces and were generally more likely to be active in them. Children in greener neighbourhoods obtained a substantial proportion of their MVPA from greenspaces, highlighting the public health importance of these places

Conclusions. These novel methodologies are allowing us to refine our measurement of how the environment might facilitate physical activity behaviours. Moving forward, it is likely that policy will be driven by the findings from evaluations of interventions and ‘natural experiments’. GPS will play a central role in these evaluations by allowing us to directly observe actual patterns of behaviour change, as evidenced by our current work on the Commuting and Health in Cambridge study.

ACKNOWLEDGEMENTS This work was undertaken by the Centre for Diet and Activity Research (CEDAR), a UKCRC Public Health Research Centre of Excellence. Funding from the British Heart Foundation, Economic and Social Research Council, Medical Research Council, the National Institute for Health Research, and the Wellcome Trust, under the auspices of the UK Clinical Research Collaboration, is gratefully acknowledged.