Obesity‐related health impacts of active transport policies in Australia – a policy review and health impact modelling study

Abstract

Objective: To review Australian policies on active transport, defined as walking and cycling for utilitarian purposes. To estimate the potential health impact of achieving four active transport policy scenarios. Methods: A policy review was undertaken, using key words to search government websites. Potential health benefits were quantified using a cohort simulation Markov model to estimate obesity and transport injury‐related health effects of an increase in active transport. Health adjusted life years (HALYs) gained and healthcare cost savings from diseases averted were estimated. Budget thresholds to achieve cost‐effectiveness were estimated for each scenario. Results: There is broad recognition of the health‐related benefits of active transport from all levels of Australian government. Modelling results suggest significant health‐related benefits of achieving increased prevalence of active transport. Total HALYs saved assuming a one‐year effect ranged from 565 (95%UI 173–985) to 12,105 (95%UI 4,970–19,707), with total healthcare costs averted ranging from $6.6M (95%UI $1.9M‐11.3M) to $141.2M (95%UI $53.8M–227.8M). Conclusion: Effective interventions that improve rates of active transport may result in substantial healthcare‐related cost savings through a decrease in conditions related to obesity. Implications for public health: Significant potential exists for effective and cost‐effective interventions that result in more walking and cycling.

What Is the Best Practice Method for Quantifying the Health and Economic Benefits of Active Transport?

“…Table 2). The most commonly studied active transport mode was cycling (n = 8) [17,21,[23][24][25][26]28,31], followed by walking and cycling (n = 6) [8,10,18,19,22,29] and walking (n = 2) [30,32]. The remaining three studies looked at physical activity in general [9,20,27].…”

“…Exposures considered in the studies in relation to active transport and health outcomes were physical activity, road transport related injuries and air pollution. Most studies included all three exposures (n = 10) [8,9,19,21,23,24,[26][27][28], five studies considered physical activity only [20,22,29,30,32], three studies physical activity and road transport injuries [17,18,31], and one study only included air pollution [25]. The health outcomes included for the different exposures varied between studies.…”

“…For physical activity commonly included outcomes were all-cause mortality, cardiovascular disease, colon cancer, breast cancer, diabetes, dementia and depression. One study focused on obesity related health outcomes ischaemic heart disease, hypertensive heart disease, ischaemic stroke, diabetes, colorectal cancer, kidney cancer, breast cancer, endometrial cancer and osteoarthritis [18] (Table 2). Road transport related injury morbidity and mortality outcomes were usually derived from local registry data.…”

“…The most often applied economic evaluation method was cost benefit analysis (n = 8) [8,10,17,19,22,29,30,32] followed by cost effectiveness analysis (n = 3) [23,26,31] and cost utility analysis [18,20]. Six studies did not include an economic evaluation but were included in the review because they presented methods to quantify the impact of active travel on health and could be extended for use in economic evaluations [9,21,24,25,27,28].…”

“…Most studies did not apply a discount rate in the main analysis [8,9,19,21,22,[24][25][26][27][28]30,32]. Studies which applied discounting used 3% [18,20,23,29] and 5% [10,17,31] discount rates.…”