Relative Risk of Injury and Death in Ambulances and Other Emergency Vehicles

THOMCO EMS SAFETY NET SEMINAR, 2007

Relative Risk of Injury and Death in Ambulances and Other Emergency Vehicles

Les R. Becker, Ph.D., NREMT-PAssociate Research ScientistPublic Services Research InstitutePacific Institute for Research & EvaluationCalverton MD 20705


Acknowledgements

• This research was supported by US Health Resources and Services Administration Emergency Medical Services to Children Grant No. 1 H15 MC00069 to the Johns Hopkins University and Grant Number 5 RO1 OH03750-02 to the Pacific Institute for Research and Evaluation.


Introduction

• EMS response is a fundamental feature of EMS systems (Boyd et al., 1983).

• Ambulance crash studies have lagged behind the growth of EMS in the U.S.

• The first examinations of ambulance crashes began in the early 90’s.


Overview

• Review of Early Studies• Review of the PIRE Study• Review of EMS Seat Belt Use• Discussion of Prevention Approaches• Proposal of a New Approach


Earlier Studies

• Auerbach (1987) studies a very small sample of Tennessee ambulance crashes:– Approximately 50% of vehicle-drivers

and front-seat occupants were wearing occupant restraints;

– Over one-half of prone stretcher patients were restrained;

– 15% of bench seat and 100% of jump seat patients were wearing restraints.


“We conclude that passenger restraints for both ambulance attendants and passengers should be mandatory and we suggest that traffic signals be strictly heeded at intersections and speed limits in urban settings be obeyed.”

Auerbach et al., 1987


Earlier Studies

• Larmon et al. (1993) reported that 67.9% of 900 EMTs surveyed identified inhibition of patient care as a reason for non-use in the patient compartment.


Earlier Studies

• Saunders and Heye (1993)– San Francisco

Public Health Department ambulance crashes;

– Over 27 months;

Locale Vehicle Type Collisions per 100-million miles

traveled

All CA. All 213.2

SF Ambulances 13,333


Earlier Studies

• Four percent of 439 emergency medical technicians responding to a survey in New England reported that they had been involved in a crash (Schwartz et al. 1993)

• Sayeh et al. (1998) surveyed 2,672 EMTS in New England and Los Angeles.– 37% in New England reported crash

involvement;– 26% in LA reported crash involvement.


Earlier Studies

• Pirrallo and Swor (1994) compared emergency and non-emergency ambulance crash fatalities.– Retrospective, cross-sectional,

comparative analysis of 109 fatal crashes (126 deaths) from 1987-1990 using FARS data;

– NY, MI, CA and NC accounted for 37% of all fatal crashes.


Earlier Studies

• Pirrallo and Swor (1994) [cont’d]:– 69% occurred during emergency runs

and 31% occurred during non-emergency runs;

– Most emergency run fatal crashes occurred between 1200h and 1800h.

– Most non-emergency fatal crashes occurred when lighting conditions were poor.


Earlier Studies

• Pirrallo and Swor (1994) [cont’d]:– No statistically

significant differences between emergency and non-emergency crashes based:

Day of week

Season Atmos. Conditions

Roadway Surface

Type

Roadway Alignment

Relation to Junction

Manner of Collision

Year Manufact

ured

Vehicle Role

Vehicle Maneuver

Manner Leaving Scene

Extent of Deformati

on

Violations Charged

# of Fatalities

Roadway Surface

Condition

Speed Limit


Earlier Studies

• Biggers et al. (1996) studied one year of ambulance crash data in Houston.– Driver history of a prior EMS vehicle

crash was a key risk factor for future crashes.

• Drivers with a history of previous crashes were involved in 33% of all collisions.

• Five drivers accounted for 88.2% (15/17) of all injuries.


Earlier Studies

• Kahn et al. (2001) analyzed 1987-1997 FARS data and found that unrestrained rear occupants were most at risk for fatal and/or incapacitating injuries.– Most crashes occurred at intersections;– Dry, straight, improved roads;– On clear days;– Striking a second vehicle;– 84% of the crashes involved fatalities;– 78% of the fatalities were not ambulance

occupants;

Our Work


Methods

• Merged 1988 through 1997 GES and FARS data;

• Police, ambulance vehicles and fire trucks;

• Modified KABCO scale– No injury;– Possible/non-incapacitating injury– Incapacity injury– Fatal injury


Methods

• Ordinal logistic regression rather than separate odds ratio calculations;

• Independent variables:– Vehicle type– Response Mode – Restraint Use– Seating position

• Dependent variable– Injury severity (KABCO score)

Results


Number of Crashes, 1988-1997

Fatal Non-fatal Total

Ambulance 305 36,693 36,998

Fire trucks 166 29,790 29,956

Police Cars 1,113 183,371 184,984


Number of Fatalities, 1988-1997

EVO’s Others Total

Ambulance 74 286 360

Fire trucks 43 152 195

Police Cars 228 971 1,199


Number of Non-Fatals,1988-1997

EVO’s Others Total

Ambulance 10,398 12,545 22,943

Fire Trucks 3,660 6,851 10,511

Police Cars 49,950 45,442 91,392


Injury Severity of Ambulance Occupants, 1988-1997

Fatal 71 (0.11)

Incapacitating 1,669 (2.70)

Possible/ Non-incapacitating

7,796 (12.62)

No Injury 52,248 (84.57)

Total 61,784


Incapacitating InjuriesBy Response, Restraint Use & Seating Position

Emergency Front R 390

U 13

Back R 5

U 531

Routine Front R 313

U 220

Back R 0

U 197

Total 1,669


Fatal InjuriesBy Response, Restraint Use & Seating Position

Emergency Front R 4

U 3

Back R 6

U 18

Routine Front R 7

U 6

Back R 8

U 19

Total 71


Relative Risks


Summary of Findings

• Unrestrained ambulance occupants involved in a crash had nearly 4 times greater risk of fatality than did restrained ambulance occupants.

• Unrestrained ambulance occupants involved in a crash had nearly 6.5 times greater risk of suffering an incapacitating injury than did restrained ambulance occupants.


Summary of Findings

• The risk of a fatality versus no injury for ambulance rear occupants was over 5 times greater for ambulance rear occupants than for front-seat occupants if involved in a crash.

• Ambulance occupants traveling non-emergency were 2.7 times more likely than occupants traveling emergency to be killed if involved in a crash.


Summary of Findings

• Ambulance occupants traveling non-emergency were nearly 1.7 times more likely than occupants traveling emergency to suffer an incapacitating injury if involved in a crash.


Conclusions

• Clearly, occupant restraints are not used consistently in ambulances.

• Unrestrained ambulance occupants, occupants riding in the rear compartment and especially unrestrained occupants riding in the rear compartment are at substantially increased risk of injury and death when involved in a crash.

• One prior study suggests that occupant restraints are more commonly used for patients than for crew members.


Implications for EMS Safety Practices

• Ambulance occupants, including providers, should use safety restraints whenever feasible.

• Individuals accompanying patients during transport should ride in the front seat of the ambulance whenever feasible.

SEAT BELTS & PREVENTION

Prevention Fact!


“The use of safety belts is the single most effective means of reducing fatal and nonfatal injuries in motor vehicle crashes.”

Dinh-Zarr, Sleet, Schultz et al., 2001


Seat Belt Use in the U.S.

What do we know about seat belt use in EMS?


Perceived Need for Freedom

Cardiac Arrest 82%

Chest Pain or Dysrhythmia

63%

Shortness of Breath 38%

Trauma 41%

Cook et al., 1991


Seat Belt Use by Providers

% Rarely Wearing Safety Belts (<5%

use)

% Always Wearing Safety Belts (>95%

use)

Routine front seat 3.7 74.0

Emergency front seat

3.9 80.6

Routine back compartment

59.4 7.0

Emergency back compartment

77.4 3.2

Larmon et al., 1993


Prevention Approaches

• The ‘Three E’s’– Education– Engineering– Enforcement

More Prevention Fact!

Single Approaches In Isolation are Rarely

Effective!


Solutions?

• Education– EVOC– Driving Simulators

• Engineering– Speed regulators (“governors”)– “Black Box” Approaches– Harness Systems

• Enforcement– Organizational policies and sanctions


Solutions?


Effectiveness?

• At least one small-scale study– 36 vehicles over 18 months– >250 drivers– Over 1.9 million miles, distance between penalty

counts increased from baseline of 0.018 to high of 15.8 miles

– Seatbelt violations from 13,500 to 4• The vendors of systems marketed today advocate

effectiveness based on small-scale trials.• NIOSH will be reporting preliminary findings from their

harness studies at the upcoming NHTSA-sponsored Ground Ambulance Safety Roundtable.


Another Approach?


Provider Safety


Patient Safety


Patient and Provider Safety Together (PaPST)• Integrating optimal patient care with

optimal provider safety.• Preplanning ALS & BLS activities to occur

during ‘natural’ lulls in call time. • Performing ALS skills early in the time

sequence of a call when the provider is already out of the vehicle.

• Engineering the vehicle interior so that routinely used equipment is safely within restrained reach of the provider.


PaPST

Crucial Equipment Secured & Within

Reach of a Restrained Provider

Infusion Pumps

Checked at Originating Facility

IV Access Prior to

Transport

Airway Accessed Prior to Transport

Provider Safety +?Patient Safety +?Task


PaPST

• Even if harnesses are effective, there are costs to upgrade a fleet.

• New technology diffuses slowly and every day we wait translates into additional injures and deaths.

• We start by retraining providers in methods of managing the call environment (e.g., continuing education).

• We establish policies and monitoring practices.• Ultimately, we incorporate PaPST-like concepts

into our training curricula.


References

• Available Upon Request


Coming Soon!

• In late May….

Thank You!!

Relative Risk of Injury and Death in Ambulances and Other Emergency Vehicles

Documents

Transcript of Relative Risk of Injury and Death in Ambulances and Other Emergency Vehicles