Measuring Non-fatal Road Injury
Professor James Harrison
Research Centre for Injury Studies and
AIHW National Injury Surveillance Unit
Flinders 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
‘severe’,
etc.for
don’t
havedeaths
specific
• Much‘Serious’,
more to
it than
road
and generally accepted meanings.
• 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
‘severe’,
etc.for
don’t
havedeaths
specific
• Much‘Serious’,
more to
it than
road
and generally accepted meanings. AIS?
• 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
• MuchAIS
more
to it than
for these
roadand
deaths
‘maintains
ties’ with
other
or components
of severity:
• Whichdimensions
consequence
(or outcome)?
- Threat to life; mortality
- Energy dissipated
/ absorbed
– Probability
of having
died (though did not)
- Tissue damage
– Disability
(Whichneed
domains?
Ascare
at when?)
- Hospitalisation;
for intensive
- Treatment:
/ costAs at when?)
– Dollar
cost (Ofduration
what?/ complexity
To whom?
- Disability: temporary; permanent
- Impairment
Threshold
for inclusion?
- Quality of life
•
• Directly observed cases? Weighted counts?
Research Centre for Injury Studies • Flinders University • Australia
Severity
• MuchAIS
more
to it than
for these
roadand
deaths
‘maintains
ties’ with
other
or components
of severity:
• Whichdimensions
consequence
(or outcome)?
- Threat to life; mortality
- Energy dissipated
/ absorbed
– Probability
of having
died (though did not)
- Tissue damage
– Disability
(Whichneed
domains?
Ascare
at when?)
- Hospitalisation;
for intensive
- Treatment:
/ costAs at when?)
– Dollar
cost (Ofduration
what?/ complexity
To whom?
- Disability: temporary; permanent
- Impairment
Threshold
for inclusion?
- Quality of life
•
• Directly observed cases? Weighted counts?
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)
This choice is not self-evident. However, it
– Disability (Which
domains? As at when?)
is feasible to produce estimates for the same
– Dollar cost (Of
what?
To of
whom?
As one
at when?)
cases
in terms
more than
outcome.
• 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
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)
100
80
Upper good recovery
Lower good recovery
Upper moderate disability
60
Lower moderate disability
Upper severe disability
Lower severe disability
40
Vegetative state
Death
20
0
6
All
ma
u
t ra
s
ca
12 24
es
6
12 24
All
12 24
t
an
p
ccu
O
V
es
s
ca
I
RT
6
M
6
12 24
list
M
c
rcy
o
t
o
l
da
e
P
6
12 24
list
c
y
c
6
12 24
ian
tr
es
d
Pe
Months of follow-up
Type of case
Notes: RTI = Road Traffic Injury MV = Motor Vehicle
Research Centre for Injury Studies • Flinders University • Australia
Survivors to discharge after serious injury:
outcomes to 24 months (Victoria; onset 2007-12)
Categories of Glasgow
Outcome Scale - Extended
100
80
Upper good recovery
Lower good recovery
Upper moderate disability
60
Lower moderate disability
Upper severe disability
Lower severe disability
40
Vegetative state
Death
20
0
6
All
ma
u
t ra
s
ca
12 24
es
6
12 24
All
12 24
t
an
p
ccu
O
V
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RT
6
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6
12 24
list
M
c
rcy
o
t
o
l
da
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P
6
12 24
list
c
y
c
6
12 24
ian
tr
es
d
Pe
Months of follow-up
Type of case
Notes: RTI = Road Traffic Injury MV = Motor Vehicle
Research Centre for Injury Studies • Flinders University • Australia
Survivors to discharge after serious injury:
outcomes to 24 months (Victoria; onset 2007-12)
100
80
Upper good recovery
Lower good recovery
Upper moderate disability
60
Lower moderate disability
Upper severe disability
Lower severe disability
40
Vegetative state
Death
20
0
6
All
ma
u
t ra
s
ca
12 24
es
6
12 24
All
12 24
t
an
p
ccu
O
V
es
s
ca
I
RT
6
M
6
12 24
list
M
c
rcy
o
t
o
l
da
e
P
6
12 24
list
c
y
c
6
12 24
ian
tr
es
d
Pe
Months of follow-up
Type of case
Notes: RTI = Road Traffic Injury MV = Motor Vehicle
Research Centre for Injury Studies • Flinders University • Australia
Survivors to discharge after serious injury:
outcomes to 24 months (Victoria; onset 2007-12)
100
80
Upper good recovery
Lower good recovery
Upper moderate disability
60
Lower moderate disability
Upper severe disability
Lower severe disability
40
Vegetative state
Death
20
0
6
All
ma
u
t ra
s
ca
12 24
es
6
12 24
All
12 24
t
an
p
ccu
O
V
es
s
ca
I
RT
6
M
6
12 24
list
M
c
rcy
o
t
o
l
da
e
P
6
12 24
list
c
y
c
6
12 24
ian
tr
es
d
Pe
Months of follow-up
Type of case
Notes: RTI = Road Traffic Injury MV = Motor Vehicle
Research Centre for Injury Studies • Flinders University • Australia
Survivors to discharge after serious injury:
outcomes to 24 months (Victoria; onset 2007-12)
100
80
Upper good recovery
Lower good recovery
Upper moderate disability
60
Lower moderate disability
Upper severe disability
Lower severe disability
40
Vegetative state
Death
20
0
6
All
ma
u
t ra
s
ca
12 24
es
6
12 24
All
12 24
t
an
p
ccu
O
V
es
s
ca
I
RT
6
M
6
12 24
list
M
c
rcy
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t
o
l
da
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P
6
12 24
list
c
y
c
6
12 24
ian
tr
es
d
Pe
Months of follow-up
Type of case
Notes: RTI = Road Traffic Injury MV = Motor Vehicle
Research Centre for Injury Studies • Flinders University • Australia
Summary
We should measure and monitor non-fatal road injury
Think carefully about exactly what information is needed
… and design information systems accordingly
Technical basis
Follow-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 preinjury state rather than effects of injury.
Monitoring
p(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.
Research Centre for Injury Studies • Flinders University • Australia