Research Centre for Injury Studies • Flinders University • Australia

Measuring Non-fatal Road Injury

Professor James HarrisonResearch Centre for Injury Studies and

AIHW National Injury Surveillance UnitFlinders University

October 2015

Research Centre for Injury Studies • Flinders University • Australia

Why measure serious road injury?• Deaths are important, but:

– Much less numerous than non-fatal cases– Becoming less common (thankfully)– Not a reliable guide to risk factors for disability

• Non-fatal injuries – Some are near-fatalities– Many leave persistent disability

Research Centre for Injury Studies • Flinders University • Australia

Why measure serious road injury?• Deaths are important, but:

– Much less numerous than non-fatal cases– Becoming less common (thankfully)– Not a reliable guide to risk factors for disability

• Non-fatal injuries – Some are near-fatalities– Many leave persistent disability

Measuring non-fatal road injury: - the case for doing so has become compelling - the questions now are exactly what to measure, and how best to do so.

Research Centre for Injury Studies • Flinders University • Australia

Three themes

Decide exactly what we need to know about serious road injury (…and are willing to pay for…)

• Information goals; definitions & specifications

Count the cases • Relevant attributes: sufficiently accurate, consistent & timely

Determine consequences (burden / disability / cost)• …in a way that is practicable and consistent with required attributes

(These themes are more distinct when measuring serious non-fatal road injury than when measuring road deaths.)

Research Centre for Injury Studies • Flinders University • Australia

Three themes

Decide exactly what we need to know about serious road injury (…and are willing to pay for…)

• Information goals; definitions & specifications

Count the cases • Relevant attributes: sufficiently accurate, consistent & timely

Determine consequences (burden / disability / cost)• …in a way that is practicable and consistent with required attributes

(These themes are more distinct when measuring serious non-fatal road injury than when measuring road deaths.)

Research Centre for Injury Studies • Flinders University • Australia

Severity• Much more to it than for road deaths• Which consequence (or outcome)?

– Probability of having died (though did not)– Disability (Which domains? As at when?)– Dollar cost (Of what? To whom? As at when?)

• Threshold for inclusion?• Directly observed cases? Weighted counts?

Research Centre for Injury Studies • Flinders University • Australia

Severity• Much more to it than for road deaths• Which consequence (or outcome)?

– Probability of having died (though did not)– Disability (Which domains? As at when?)– Dollar cost (Of what? To whom? As at when?)

• Threshold for inclusion?• Directly observed cases? Weighted counts?

‘Serious’, ‘severe’, etc. don’t have specific and generally accepted meanings.

Research Centre for Injury Studies • Flinders University • Australia

Severity• Much more to it than for road deaths• Which consequence (or outcome)?

– Probability of having died (though did not)– Disability (Which domains? As at when?)– Dollar cost (Of what? To whom? As at when?)

• Threshold for inclusion?• Directly observed cases? Weighted counts?

‘Serious’, ‘severe’, etc. don’t have specific and generally accepted meanings. AIS?

Research Centre for Injury Studies • Flinders University • Australia

Severity• Much more to it than for road deaths• Which consequence (or outcome)?

– Probability of having died (though did not)– Disability (Which domains? As at when?)– Dollar cost (Of what? To whom? As at when?)

• Threshold for inclusion?• Directly observed cases? Weighted counts?

AIS ‘maintains ties’ with these and other dimensions or components of severity:- Threat to life; mortality- Energy dissipated / absorbed- Tissue damage- Hospitalisation; need for intensive care- Treatment: duration / complexity / cost- Disability: temporary; permanent- Impairment- Quality of life

Research Centre for Injury Studies • Flinders University • Australia

Severity• Much more to it than for road deaths• Which consequence (or outcome)?

– Probability of having died (though did not)– Disability (Which domains? As at when?)– Dollar cost (Of what? To whom? As at when?)

• Threshold for inclusion? • Directly observed cases? Weighted counts?

AIS ‘maintains ties’ with these and other dimensions or components of severity:- Threat to life; mortality- Energy dissipated / absorbed- Tissue damage- Hospitalisation; need for intensive care- Treatment: duration / complexity / cost- Disability: temporary; permanent- Impairment- Quality of life

But validation is mainly with respect to mortality and threat to life. Much less evidence concerning disability, impairment, quality of life.

Research Centre for Injury Studies • Flinders University • Australia

Severity• Much more to it than for road deaths• Which consequence (or outcome)?

– Probability of having died (though did not)– Disability (Which domains? As at when?)– Dollar cost (Of what? To whom? As at when?)

• Threshold for inclusion?• Directly observed cases? Weighted counts?

Research Centre for Injury Studies • Flinders University • Australia

Severity• Much more to it than for road deaths• Which consequence (or outcome)?

– Probability of having died (though did not)– Disability (Which domains? As at when?)– Dollar cost (Of what? To whom? As at when?)

• Threshold for inclusion?• Directly observed cases? Weighted counts?

This choice is not self-evident. However, it is feasible to produce estimates for the same cases in terms of more than one outcome.

Research Centre for Injury Studies • Flinders University • Australia

Severity• Much more to it than for road deaths• Which consequence (or outcome)?

– Probability of having died (though did not)– Disability (Which domains? As at when?)– Dollar cost (Of what? To whom? As at when?)

• Threshold for inclusion?• Directly observed cases? Weighted counts?

Research Centre for Injury Studies • Flinders University • Australia

Severity• Much more to it than for road deaths• Which consequence (or outcome)?

– Probability of having died (though did not)– Disability (Which domains? As at when?)– Dollar cost (Of what? To whom? As at when?)

• Threshold for inclusion?• Directly observed cases? Weighted counts?

Research Centre for Injury Studies • Flinders University • Australia

Health state after injury?• Rapid progress in knowledge based on

– Prospective follow-up of sets of cases; with– Application of health outcome measures

• How to do this?– Special studies (each a one-off)– Routinely, as part of case documentation

• A world-leading system in Victoria follows all survivors of serious trauma by CATI to 24 months.

Research Centre for Injury Studies • Flinders University • Australia

Current projects• Outcomes to 24 months

– Gabbe, Simpson, Harrison, et al. (2015) Return to work and functional outcomes after major trauma: who recovers, when and how well? Ann Surg (accepted Sept 2015)

– Reports routine follow up to 24 months of all adult major trauma patients in Victoria injured mid-2007 to mid-2012 who survived to initial discharge (n=8,844)

– Results presented here expand on those in the paper, to show additional road injury case groups

• Outcomes & experiences to 5 years – NHMRC project grant; Professor Belinda Gabbe is CI-A– Cases: all in 1 year of Victorian follow-up system, already

interviewed at 6, 12, 24 months– This project is following the whole group to 5 years and conducting

face-to-face interviews with a sample (incl. qualitative topics)

Research Centre for Injury Studies • Flinders University • Australia

Survivors to discharge after serious injury: outcomes to 24 months (Victoria; onset 2007-12)

Months of follow-up

Type of case

Notes : RTI = Road Traffic In jury MV = Motor Vehic le

0

20

40

60

80

100

Per

cent

age

of m

ajor

trau

ma

patie

nts

All trauma cases

All RTI cases

MV Occupant

Motorcyclist

Pedal cyclist

Pedestrian6 12 24 6 12 24 6 12 24 6 12 24 6 12 24 6 12 24

Upper good recovery

Lower good recovery

Upper moderate disability

Lower moderate disability

Upper severe disability

Lower severe disability

Vegetative state

Death

Research Centre for Injury Studies • Flinders University • Australia

Survivors to discharge after serious injury: outcomes to 24 months (Victoria; onset 2007-12)

Months of follow-up

Type of case

Notes : RTI = Road Traffic In jury MV = Motor Vehic le

0

20

40

60

80

100

Per

cent

age

of m

ajor

trau

ma

patie

nts

All trauma cases

All RTI cases

MV Occupant

Motorcyclist

Pedal cyclist

Pedestrian6 12 24 6 12 24 6 12 24 6 12 24 6 12 24 6 12 24

Upper good recovery

Lower good recovery

Upper moderate disability

Lower moderate disability

Upper severe disability

Lower severe disability

Vegetative state

Death

Categories of Glasgow Outcome Scale - Extended

Research Centre for Injury Studies • Flinders University • Australia

Survivors to discharge after serious injury: outcomes to 24 months (Victoria; onset 2007-12)

Months of follow-up

Type of case

Notes : RTI = Road Traffic In jury MV = Motor Vehic le

0

20

40

60

80

100

Per

cent

age

of m

ajor

trau

ma

patie

nts

All trauma cases

All RTI cases

MV Occupant

Motorcyclist

Pedal cyclist

Pedestrian6 12 24 6 12 24 6 12 24 6 12 24 6 12 24 6 12 24

Upper good recovery

Lower good recovery

Upper moderate disability

Lower moderate disability

Upper severe disability

Lower severe disability

Vegetative state

Death

Research Centre for Injury Studies • Flinders University • Australia

Survivors to discharge after serious injury: outcomes to 24 months (Victoria; onset 2007-12)

Months of follow-up

Type of case

Notes : RTI = Road Traffic In jury MV = Motor Vehic le

0

20

40

60

80

100

Per

cent

age

of m

ajor

trau

ma

patie

nts

All trauma cases

All RTI cases

MV Occupant

Motorcyclist

Pedal cyclist

Pedestrian6 12 24 6 12 24 6 12 24 6 12 24 6 12 24 6 12 24

Upper good recovery

Lower good recovery

Upper moderate disability

Lower moderate disability

Upper severe disability

Lower severe disability

Vegetative state

Death

Research Centre for Injury Studies • Flinders University • Australia

Survivors to discharge after serious injury: outcomes to 24 months (Victoria; onset 2007-12)

Months of follow-up

Type of case

Notes : RTI = Road Traffic In jury MV = Motor Vehic le

0

20

40

60

80

100

Per

cent

age

of m

ajor

trau

ma

patie

nts

All trauma cases

All RTI cases

MV Occupant

Motorcyclist

Pedal cyclist

Pedestrian6 12 24 6 12 24 6 12 24 6 12 24 6 12 24 6 12 24

Upper good recovery

Lower good recovery

Upper moderate disability

Lower moderate disability

Upper severe disability

Lower severe disability

Vegetative state

Death

Research Centre for Injury Studies • Flinders University • Australia

SummaryWe should measure and monitor non-fatal road injuryThink carefully about exactly what information is needed

… and design information systems accordingly

Technical basisFollow-up registers for outcome measurement Population data linkage, to:

Combine data on crashes with health service data to get benefits of both.Refine indicators (e.g. to minimise under- and over-counting).Improve understanding of the extent to which post-injury disability reflects pre-injury state rather than effects of injury.

Monitoringp(survival)|diagnosis. Can be suitable for comparisons (national, international). No available method is perfect. TMPM?p(disability)|diagnosis. Apply periodically-updated weights to latest set of case-data to estimate future disability.