CTF Structured Abstract: Prevention of MVA Injuries

Canadian Task Force on Preventive Health Care

Structured Abstract

Please note: In 2003, the CTF updated its Grades of Recommendations to include an "I Recommendation" for situations where insufficient evidence exists to allow a recommendation to be made. (Formerly, these situations were captured under a "C Recommendation".) This change is not retroactive, and all "C Recommendations" made prior to 2003 have not been reevaluated in light of the new "I" recommendation grade. For a discussion of these recommendation grades, please link to the 2003 article in the Canadian Medical Association Journal here.

Prevention of Motor Vehicle Accident Injuries

Adapted to the Canadian context by R. Wayne Elford, MD, CCFP, FCFP, Professor, Department of Family Medicine, University of Calgary, from the 1989 report of the U.S. Preventive Services Task Force

These recommendations were finalized by the Task Force in November 1992

Objective
Burden of Suffering
Options
Outcomes

Evidence
Values
Benefits, Harms, and Costs
Recommendations

Validation
Sponsors
Selected References

Objective

To make recommendations about the prevention of motor vehicle collision injuries in Canada.

Burden of Suffering

Of the ten industrialized western countries Canada has the fourth highest injury mortality rate (37.5/100,000) and the sixth highest motor vehicle accident (MVA) fatality rate (15.8/100,000). The rate for males is consistently almost twice that of females. Motor vehicles crashes are the leading cause of death in persons aged 5 - 24; in 1986 they accounted for 38% of all deaths in young persons aged 15-24.

High Risk Behaviours

High risk behaviours include seatbelt and alcohol use. The rate of seat belt use among those persons fatally injured was considerably less than among those with non-fatal or no injuries from MVAs. Alcohol intoxication accounts for about 40% of persons killed in motor vehicle crashes. Studies have consistently shown that fatally injured drivers are more likely to have a blood alcohol level of at least 0.10% than are drivers who are not killed.

Medical Impairment

Impaired vision, impaired hearing, decreased flexibility and dexterity, and slowing of information processing capability result in abnormally high accident rates in the elderly when exposure is taken into account. Less than 0.5% of all deaths of elderly people are the result of road accidents, but elderly drivers are over represented in low velocity, property-damage-only collisions. Whether drivers with concomitant medical conditions have excessive motor vehicle accidents is less clear.

Off Road Vehicles

Most injuries associated with all-terrain vehicles (ATVs) occur when the driver loses control, the vehicle falls over, the driver is thrown from the vehicle, or the vehicle collides with fixed objects such as fences or trees. The 1987 data for numbers of vehicles in use and mortality, without reference to patterns of vehicle use, yielded annual death rates of 1.7/1000 for 3-wheeled and 1.2/1000 for 4-wheeled ATVs. Canadian and U.S. studies have revealed the following risk factors: excessive speed, improper apparel and non-use of helmets, inexperience, and alcohol abuse.

Options

Primary options were legislation and physician counselling about occupant protection systems (lap and shoulder belts, airbags, child safety seats, safety helmets) and health behaviours (driving while intoxicated, use of seat belts, infant safety seats). Monitoring of patients for medical impairment was also considered.

Outcomes

Outcomes included crash mortality; injuries (moderate-to-serious, head, non-crash); severity of injuries; hospital admission; hospital charges; and use of occupant restraints.

Evidence

A MEDLINE search from 1981 to 1991 using the MeSH headings motor vehicle, accident prevention and primary care physician yielded 151 citations. As well, the 1989 report of the U.S. Preventive Services Task Force was used extensively. Study results were synthesized in table or graphic format only.

Recommendations were graded as:

A Good evidence to support the recommendation that the condition be specifically considered in a PHE.

B Fair evidence to support the recommendation that the condition be specifically considered in a PHE.

C Poor evidence regarding inclusion or exclusion of the condition in a PHE, but recommendations may be made on other grounds.

D Fair evidence to support the recommendation that the condition be specifically excluded from consideration in a PHE.

E Good evidence to support the recommendation that the condition be specifically excluded from consideration in a PHE.

Quality of evidence was rated according to 5 levels:

I Evidence from at least 1 properly randomized controlled trial (RCT).

II-1 Evidence from well-designed controlled trials without randomization.

II-2 Evidence from well-designed cohort or case-control analytic studies, preferably from more than 1 centre or research group.

II-3 Evidence from comparisons between times or places with or without the intervention. Dramatic results in uncontrolled experiments could also be included here.

III Opinions of respected authorities, based on clinical experience, descriptive studies or reports of expert committees.

Values

The 13-member Task Force of experts in family medicine, geriatric medicine, pediatrics, psychiatry and epidemiology used an evidence-based method for evaluating the effectiveness of preventive health care interventions. Recommendations were not based on cost-effectiveness of options. Patient preferences were not discussed.

Background papers providing critical appraisal of the evidence and tentative recommendations prepared by the chapter author were pre-circulated to the members. Evidence for this topic was presented and deliberated upon in 1- to 2-day meetings, 2 to 3 times per year from January 1993 to June 1993. Consensus was reached on final recommendations.

Benefits, Harms, and Costs

Effectiveness of occupant restraint systems has been demonstrated in laboratory experiments, postcrash injury comparisons and postcrash judgments regarding the probable effects of restraints. Estimates from non-randomized controlled trials suggest that proper use of lap and shoulder restraints decreased the risk for moderate-to-serious injury in front seat occupants by 45% to 55% and decreased risk for mortality by 40% to 50%. Victims who were brought to the hospital had less severe injuries, were less likely to be admitted, and incurred lower hospital charges. Despite this, it is estimated that 3-point seat belts are not worn by 25% of Canadians. The overall safety benefit of a combination airbag system and lap-shoulder belt has not yet been determined.

Evidence from non-randomized controlled trials suggests that persons who refrain from drinking and driving have a significantly reduced risk of injury or death from motor vehicle accidents.

Few studies exist on the effectiveness of physician counselling on seat belt use or drinking and driving behaviour. Studies examining the use of infant safety seats (before use was mandated by law) found significant short-term improvements immediately after newborns were discharged from hospital, and for the next few months.

Descriptive studies report an excess of motor vehicle accidents among persons with known concomitant medical conditions. For example, elderly persons with impaired vision or hearing, decreased flexibility and dexterity, or slowing of information processing capabilities have abnormally high accident rates.

Cohort analytic studies in regions where helmet use for motorcyclists is mandated by law report a 30% reduction in mortality, and a 75% reduction in head injuries.

Recommendations

Recommendation grade [A, B, C, D, E] and level of evidence [I, II-1, II-2, II-3, III] are indicated after each recommendation. Citations in support of individual recommendations are identified in the guideline text.

There is good evidence to implement legislation mandating the use of seatbelts and child restraints in automobiles [A, II-1] and safety helmets when riding on motorcycles or all-terrain vehicles [B, II-2], and to implement "do not drink and drive" legislation [A, II-2].
There is fair evidence to include (in the PHE) physician counselling regarding the use of seatbelts and child restraints [B, II-3].
There is insufficient evidence to include or exclude physician counselling of patients regarding the use of safety helmets [C, III] and regarding drinking and driving [C, no studies].
There is insufficient evidence to include or exclude physician monitoring of patients for medical impairment [C, III].

Validation

This report was externally peer reviewed. Use of safety belts and child safety seats is legislated in all Canadian provinces and in 50 states. The Canadian Medical Association, the College of Family Physicians, and the National Highway Traffic Safety Administration recommend that physicians counsel patients to use occupant restraints. The Canadian Medical Association supports legislation to reduce drinking and driving, and the American Academy of Pediatrics supports physician counselling of parents and children on drinking and driving.

Selected References

Source Document

Elford RW. Prevention of motor vehicle accident injuries. In: Canadian Task Force on the Periodic Health Examination. Canadian Guide to Clinical Preventive Health Care. Ottawa: Health Canada, 1994; 514-24.

Other

Counseling to prevent motor vehicle injuries. In U.S. Preventive Services Task Force. Guide to Clinical Preventive Services: An Assessment of the Effectiveness of 169 Interventions. Baltimore: Williams & Wilkins, 1989, 315-20.

Link to Full Text of this review

Link to Summary Table of Recommendations of this review

Link to Selected References list of this review

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A	Good evidence to support the recommendation that the condition be specifically considered in a PHE.
B	Fair evidence to support the recommendation that the condition be specifically considered in a PHE.
C	Poor evidence regarding inclusion or exclusion of the condition in a PHE, but recommendations may be made on other grounds.
D	Fair evidence to support the recommendation that the condition be specifically excluded from consideration in a PHE.
E	Good evidence to support the recommendation that the condition be specifically excluded from consideration in a PHE.

I	Evidence from at least 1 properly randomized controlled trial (RCT).
II-1	Evidence from well-designed controlled trials without randomization.
II-2	Evidence from well-designed cohort or case-control analytic studies, preferably from more than 1 centre or research group.
II-3	Evidence from comparisons between times or places with or without the intervention. Dramatic results in uncontrolled experiments could also be included here.
III	Opinions of respected authorities, based on clinical experience, descriptive studies or reports of expert committees.