Motorcycle crashes & trauma: merging NZ

Transport Agency Crash Analysis System &

Midland Trauma System

Trauma Registry datasets to gain new insights

Colin Morrison, NZ Transport Agency

Dr Alastair Smith, Midland Trauma System

Bringing together individual strengths in data & expertise

Midland Trauma SystemEstablished 2010 to support trauma clinical service development and trauma research_.

MTS Hub team

Waikato Hospital

Hamilton

National

Minimum Dataset

for major trauma

CASCrash Analysis System

A vital tool in New Zealand’s drive to reduce road trauma

CAS manages, analyses & maps traffic crash & related data

Over 1M Police TCRs back to 1980

Original photograph: Auckland Rescue Helicopter Trust

with kind permission

CAS

Motorcyclist casualties (MBC) & hospital admissions Midland DHBs (excludes Tairāwhiti DHB) 2012-2016

1,331 motorcyclists 1,207 injury traffic crashes

774 minor injuries433 seriously injured 74 died50 not injured

Motorcyclist casualties (MBC) & hospital admissions Midland DHBs (excludes Tairāwhiti DHB) 2012-2016

Trauma Registry1,614 MBC injury admissions

689 on-road MBC925 were off-road MBC

312 on farm 454 sport 159 countryside/other

METHODOLOGYNZ Transport Agency CAS & MTS Trauma Registry data matching

Merge CAS Crash & Person datasets on CRASH_ID

All NZ, 2012-2016: 10,527 MBC (PERS_CAS_TYPE=M (Motorcycle) + P(Moped))

Concatenate CRASH_DATE & PERS_DOB to create key

Mapped AU_ID field to DHBs & filtered for Midland DHBs (excluding Tairāwhiti DHB): 1,331

MTS Trauma Registry

Extract all trauma records 2012-2016, cause MBC, Midland DHBs (excluding

Tairāwhiti DHB)

Concatenate INJ_DATE & DOB to create key

Total 1,614, subset to on road: 689

NZTA + Registry datasets merged in R.Studio using key

Where no match was found, additional checks at individual patient/crash person performed using multiple additional fields

CAS

Motorcyclist casualties (MBC) & hospital admissions Midland DHBs (excludes Tairāwhiti DHB) 2012-2016

Trauma Registry

386 matched

29% of motorcyclists

were admitted to hospital

303 not matched

44% not found in CAS

689 on-road MBC admissions

Motorcyclists admitted to hospital not matched

303129 (42.6%) self-presented

124/129 (96.4%) admitted non-major injury *(ISS<13)

5/129 (3.6%) admitted with major injury *(ISS>12)

*ISS=Injury Severity Score

Trauma Registry

CAS injury crashes & TR MBC admitted(Motorcyclists involved n=1,331 versus motorcyclists admitted n=386)

CAS admissions

AdmittedNot

admittedTotal

motorcyclists

CAS crash severity*

Minor 90 (12%) 678 (88%) 768 (100%)

Serious 281 (59%) 194 (41%) 475 (100%)

Fatal 15 (17%) 75 (83%) 90 (100%)

Total 386 (29%) 947 (71%) 1,331 (100%)

*worst injury in the crash

CAS crash severity & injury severity score(CAS crash severity versus survival trauma admitted patients n=386)

Trauma injury severity

Major injury(ISS > 12)

Non-majorinjury

(ISS < 13)Total MBC

CAS crash severity

Minor 11 (12.2%) 79 (87.8%) 90 (100%)

Serious 88 (31.3%) 193 (68.7%) 281 (100%)

Fatal 13 (86.7%) 2 (13.3%) 15 (100%)

Total 112 (29.0%) 274 (71.0%) 386 (100%)

CAS crash severity & MBC injury survival(CAS crash severity versus survival trauma admitted patients n=386)

MTS Trauma

Survival

Died Survived Total MBC

CAS crash severity

Minor - 90 (100%) 90 (100%)

Serious - 281 (100%) 281 (100%)

Fatal 10 (67%) 5 (33%) 15 (100%)

Total 10 (2.6%) 376 (97.4%) 386 (100%)

MBC hospitalised patients n=689

10 deaths 3 ED, 3 ICU, 3 operating room & 1 ward

All were classified in MTS as major injury (ISS > 12)

All 10 were matched in both CAS & the Trauma Registry

Motorcyclist casualties (MBC) & hospital admissions Midland DHBs (excludes Tairāwhiti DHB) 2012-2016

Matched MBC Non-matched Total admitted

Total 386 (56.0%) 303 (44.0%) 689 (100%)

Injury severity

Major (ISS>12) 112 (71.3%) 45 (28.7%) 157 (100%)

Minor (ISS<13) 274 (51.5%) 258 (48.5%) 532 (100%)

Gender

Male 331 (55.8%) 262 (44.2%) 593 (100%)

Female 55 (57.3%) 41 (42.7%) 96 (100%)

Motorcyclist injury severity score & genderMatched n=386 vs non-matched n=303 MBC ISS & gender comparison

CAS

Under-reporting of motorcyclist injury in CAS

Trauma Registry1,331 motorcyclists involved 433 seriously injured

689 on-road MBC admissions 303 of MBC not matched in CAS

Implies a 19%under-reporting of injuries in

CAS[303/(303+1331-74*) denominator includes the 50 that police reported as not injured]

*removing all deaths from the calculation

CAS

Under-reporting of motorcyclist injury in CAS

Trauma Registry1,331 motorcyclists involved 433 seriously injured

689 on-road MBC admissions 303 of MBC not matched in CAS

CAS is in fact under-reporting serious motorcyclist casualties

34%[Police reported 433 seriously injured motorcyclists & MBC admissions were 679* ]

*removing the 10 admitted deaths from the calculation

29% of motorcyclists were admitted to hospital

CAS under-reports seriously injured motorcyclists

Generally good concordance between CAS injury severity & MTS ISS major/minor bands

Many non-matched were minor injury (ISS<13)

Non-matched were often female pillions

More non-matched were self-reported

Age/gender demography similar, predominantly younger & older male riders

Key findings & insights

Time series mapping of matched crashes CAS-admissions Midland 2012-2016[ Fatal crashes RED Serious injury crashes BLUE Minor injury crashes GREEN ]

Time series mapping of the others crashes in CAS Midland 2012-2016 those, taken to hospital but not admitted, those that died at scene & those whose injuries were minor

To be continued The economic burden of specific injuries

U.Waik investigate matched/non matched

Feasibility of predictive application

Midland Trauma System

Working together on minimising transport related harm