Safety Information Systems
Do Seat Belts Reduce Injuries?
Maine Crash Facts, 1996
Maine Crash Outcome Data Evaluation System (CODES)
A study was made of drivers and passengers who were involved
in motor vehicle crashes during 1996 to determine their seat belt
use and rates of injury. The study was limited to occupants of passenger
cars, vans, and light trucks who were age 5 or older. After removal
of occupant records with missing data 71,552 occupants involved
in crashes were studied.
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Table 1. Seat belt use and
injury outcomes, Maine 1996
| Measure# |
Not
belted* |
Belted* |
Total |
| Occupants |
6,307 |
65,245 |
71,552 |
| Injured |
2,323 |
8,138 |
10,461 |
| Transported by EMS |
1,149 |
3,102 |
4,251 |
| Inpatient hospital
charges |
$3.7
million |
$3.8
million |
$7.5
million |
| Hospitalized or died |
296 |
344 |
640 |
| Hospitalized or died
with head injury |
113 |
98 |
211 |
| Fatalities |
62 |
35 |
97 |
| Years of potential
life lost |
2,508 |
1,215 |
3,723 |
| * The percentage
of occupants reported as unbelted on police crash
reports is lower than Maine observational studies
would predict. # 16,000 occupant records were eliminated
from the study due to missing values. Therefore,
counts underestimate actual experience. EMS and
hospitalization data based on linked records. |
|
Of those reported as not belted, 2,323 (37 percent) were injured,
1,149 required EMS transport, 296 were hospitalized or died, and
the 62 fatalities represented 2,508 years of potential life lost.
While those reported as not belted represented less than 1
in 10 of all occupants involved, they represented more than half
of the occupants hospitalized or dying with a head injury.
For those hospitalized, the average inpatient charge for those
unbelted was $15,076 compared to $11,950 for those belted. For unbelted
passengers, 23 percent of the charges were incurred by occupants
without insurance and 62 percent by commercial insurance - a cost
issue for employers.
A special analysis was constructed to adjust for differences
in the age, sex and seating position of the occupants, the type
of crash (head-on, rollover), and other variables that contribute
to crash severity. Adjustment was also made for potential over-reporting
of belt use to police.
The results indicated that occupants not using belts
were 32 percent more likely to be injured and 2.8 times more likely
to be hospitalized or die with a head injury than belted occupants.
 |
Table 2. What is the likelihood
of injury for occupants not using seat belts?
|
Outcome |
Odds
of injury for those unbelted compared to those
belted |
| Any injury |
1.32 |
| EMS transport, hospitalized
or died |
1.57 |
| Hospitalized or died |
2.2 |
| Died |
2.34 |
| Hospitalized or died with a
head injury |
2.79 |
|
Seat belts not only reduced the risk of injury but had a greater
impact on reducing the risk of the more serious types of injury.
These results correspond with estimates from other CODES states
about the effectiveness of seat belts in reducing the risk of injury.
Although seat belt use rates have increased during the past
six years, Maine still falls below national averages and well below
(by 25 percent) the national goal for year 2000.
Maine observational studies show that belt use rates are highest
for children and women and lowest for adult males.
In states with primary enforcement, a citation can be written
whenever a law enforcement officer observes an unbelted driver or
passenger, while states with secondary enforcement, require an officer
to stop a violator for another infraction before issuing a citation.
Eight of the nine states with the highest belt use rates have
primary enforcement laws.
In December, 1995, Maine revised the motor vehicle statute
to include secondary enforcement for all ages (previously there
was no law for adults).
Results of Maine CODES data indicate that as belt use rates
have increased the number of hospitalizations has declined.
From 1991 to 1997 the belt use rate has increased from 36
percent to 61 percent. Between 1991 and 1996 the number of hospitalizations
from motor vehicle crashes identified in the CODES linked data has
declined from 807 to 562. Between 1995 and 1996 the number of occupants
hospitalized or dying with a head injury dropped from 231 to 211.
Observational studies of seat belt use in Maine are now planned
on an annual basis. Continued measurement of injury outcomes
will help evaluate the impact of changes in belt use rates.
The Maine CODES Project Advisory Committee:
Maine Health Information Center (report and data preparation)
Maine Department of Human Services, Bureau of Health, Office of
Data, Research, and Vital Statistics (project coordinator)
Maine Department of Human Services, Childhood Injury Prevention
and Control
Maine Department of Public Safety, Bureau of Highway Safety
Maine Department of Public Safety, Emergency Medical Services
Maine Department of Secretary of State, Bureau of Motor Vehicles
Maine Department of Transportation
Physicians from Maine Medical Center and Eastern Maine Medical Center
Supported by the National Highway Traffic Safety Administration
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