Incidental physical activity in Melbourne, Australia: health and economic impacts of mode of transport and suburban location.

Abstract

Using the known health impacts of physical activity (PA), levels of incidental PA in Melbourne were analysed, and after determining key behavioural associations, economic modelling estimated potential long-term health and economic benefits of changes in active transport (AT) patterns. A cross-sectional survey (VISTA07-08) obtained daily travel data from 29840 individuals of all ages in Melbourne evenly spread over 364 days of the year. Correlates of adequate PA were analysed. The health and economic impact of changes in AT from postulated changes in (1) mode of transport, and (2) transport use by urban sub-region, were modelled. 15.1% of individuals had adequate incidental PA. Private vehicle users averaged 10.0min PA, public transport users 35.2min and walkers/cyclists 38.3min daily. Distance from city centre was strongly inversely correlated with adequate PA. Conservative modelling of postulated changes in AT patterns found annual savings of 34-272 deaths, 114-903 new cases of disease and 442-3511 DALYs. Lifetime savings accounted for 17300-70100 days of home-based/leisure time production, and savings of $1.5-12.2million in the health sector and $2.9-22.9million in production. Public transport users, walkers, cyclists and those living closer to the city centre were more likely to gain travel-related PA sufficient for health benefits. Both transport mode and urban location were associated with levels of travel-related PA that have significant health and financial impacts. SO WHAT?: Improving population levels of incidental PA may improve health and economic outcomes. This may require changes in urban and transport infrastructure.