THAT-Brisbane

About

The Transport Health Assessment Tool for Brisbane (THAT-Brisbane) was developed as a quantitative Health Impact Assessment model to support evidence-informed planning for healthier cities. THAT-Brisbane extends on the existing and award winning THAT-Melbourne tool and demonstrates health benefits and health care cost saving associated with changing short care trips, to walking and cycling. Both THAT-Brisbane and THAT-Melbourne are publicly available in the Australian Urban Observatory (auo.org.au) and designed to increase knowledge about the implications of transport decision-making on health. Both the Melbourne and Brisbane tools quantify the impact of transport choices on health. However, THAT-Brisbane extends on previous modelling by assessing the health impacts on additional chronic diseases and health care cost savings from changing short car trips to active transport modes. Active transport, such as walking and cycling, provides an important opportunity to increase daily physical activity, particularly when more than half of Australians did not meet the requirements for physical activity as summarised in the 2017-18 National Health Survey. Health benefits gained through physical activity also continue to accumulate across the lifespan and have major long-term social and economic consequences. Physical activity has many health benefits and reduces the chance of chronic diseases such as cardiovascular disease, diabetes, cancer, dementia, and also death from all causes.

What is the Transport Health Assessment Tool for Brisbane?

The tool has been designed to measure health impacts associated with increased physical activity due to replacing short car trips under 10km by walking and cycling in Brisbane. These health impacts are assessed through 20 different scenarios where short car trips are replaced with walking, cycling or a combination of both walking and cycling. THAT-Brisbane includes quantifiable health impacts of transport on the incidence and mortality of 15 different diseases including 9 different types of cancers, depression, diabetes type 2, stroke, ischaemic heart disease, Alzheimer’s disease and dementias. Value gained through transport mode shifts to active transport are estimated through Health Adjusted Life Years with estimated costs, and health care cost savings from prevented chronic diseases per 1000 people.

Why was it developed?

The Transport Health Assessment Tool for Brisbane is a freely accessible tool that measures and quantifies health benefits and health costs derived from replacing short car trips with walking and cycling. The tool provides important research evidence to support and advocate for active transport and to make the connection between the influence of transport policies on health.

How was it developed?

Active transport scenarios are used to measure and model the impact on disease risk because of changes in physical activity from increased walking and cycling. The model is based on established travel behaviours of the Brisbane population with the baseline year of 2019 until people they die or reach the age of 100. Health benefits from physical activity accumulate over a lifespan. Consequently, the model reveals that becoming active earlier in life has greater health benefits across the lifespan through both lower incidence and mortality from disease.

Age and gender are important influences on disease risk, transport behaviour and physical activity patterns. The model accommodates differences for age and sex for a base case scenario (no changes to walking/cycling) and for each of possible scenarios beginning in 2017.

The model begins in 2019 based on the Queensland Health and Travel Survey 2017-20 and the National Health Survey (2017-20) from the Australian Bureau of Statistics.

Scenarios

Health impacts can be calculated from 20 different walking and cycling scenarios applied to replace car trips. These include trips replaced by walking (2 scenarios of different distances), cycling (3 scenarios of distance) and combined walking and cycling together (5 scenarios of different distances).

Trips are further categorised according to trip purpose: either commuting trips or all trips. Commuting trips are those related to work or education. The definition of all trips includes transport related trips to work, education, leisure, shopping, picking-up or dropping-off someone or something, or accompanying someone. Finally, the scenario combinations of walking/cycling and trip purpose were applied to age groups and gender.

Methods

In this tool we capture increases in physical activity associated with active transport scenarios and simulate potential health outcomes for the Brisbane population in 2019. Outcomes include the reduction in incidence, mortality and health benefits in the form of Health Adjusted Life Years (HALYs) and Life Years with estimated costs, and health care cost savings from prevented chronic diseases per 1000 people.

The model has three sections:

• 1. Scenarios;
• 2. Potential Impact Fractions (PIF) representing a measure of the proportional change in disease risk due to an increase in physical activity; and
• 3. Proportional multi-state life table (PMSLT).

We developed a hybrid model, where the scenarios and PIF calculations are at the individual level (micro-simulation) and the PMSLT calculations are at the macro level aggregated by age and sex groups (macro-simulation). More details of the methods can be found in the Technical Report developed for THAT-Melbourne.

Credits

The team gratefully acknowledges project support and funding from the Australian Prevention Partnership Centre and RMIT University. The project was co-led by Dr Lucy Gunn and Associate Professor Melanie Davern, with modelling development under the leadership of Dr Belen Zapata-Diomedi and modelling from Mr Steve Pemberton with modelling and web development by Dr Alan Both. The team would like to thank those who participated in the project workshops which have supported the development of this tool and accompanying material.

We further acknowledge additional technical contributions from the Public Health Modelling Team at the MRC Epidemiology Unit at the University of Cambridge for the development of THAT-Melbourne as the precursor to THAT-Brisbane. The contributions of Dr Ali Abbas were funded by the European Research Council under the Horizon 2020 research and innovation programme (grant agreement No 817754) under the GLASST: Global and local health impact assessment of transport project. Dr Belen Zapata-Diomedi was funded by a RMIT University Vice-Chancellor’s Postdoctoral Fellowship and the JIBE project (APP1192788) with some components of the code development completed during her placement at the MRC Epidemiology Unit, University of Cambridge under the supervision of Dr James Woodcock. Associate Professor Melanie Davern was also supported by a RMIT Vice Chancellor’s Senior Research Fellowship.

Download

A downloadable report that includes modelling scenario outcomes presented in THAT-Brisbane is available here and includes a suggested citation to support future evidence informed decision-making and action.