The following describes the research questions that were identified through a systematic review of population-based interventions designed to reduce injuries to motor vehicle occupants. These questions were published as part of the comprehensive evidence review conducted by the Task Force and published in a special supplement to the American Journal of Preventive Medicine (see Am J Prev Med 2001;21(4S), pp.31-47 [evidence review for interventions to increase use of child safety seats] (see Am J Prev Med 2001; 21(4S), pp. 48-65) [evidence review for interventions to increase seat belt use] and see Am J Prev Med 2001; 21(4S), pp. 66-88 [evidence review of interventions to reduce alcohol impaired driving].

Public health practitioners, policy makers, employers/purchasers, and funders are encouraged to use these findings to help guide research priorities and build a broader evidence base.

RESEARCH ISSUES

Interventions to Decrease Alcohol Impaired Driving

Effectiveness

There is sufficient or strong evidence for the effectiveness of the five interventions to reduce alcohol-impaired driving that were reviewed. However, important issues related to the effectiveness of these interventions require further research.

General questions

• How do interventions to reduce alcohol-impaired driving interact with each other (e.g., .08 BAC laws and administrative license revocation)?
• What effects do these interventions have on long-term changes in social norms regarding drinking and driving?

Laws

• How do variations in enforcement levels influence the effectiveness of laws to reduce alcohol-impaired driving?
• What are the independent effects of publicity on the effectiveness of laws to reduce alcohol-impaired driving?
• Does public compliance with new laws change in a predictable manner over time?

Sobriety checkpoints

• Does the use of passive alcohol sensors at sobriety checkpoints improve their deterrent effects?
• Are the deterrent effects of sobriety checkpoints diminished if warning signs are posted which allow drivers to avoid the checkpoints?
• How do various configurations of sobriety checkpoints (e.g., intermittent blitzes vs. continuous, weekend nights vs. random time periods, number of officers per checkpoint) affect deterrence?
• What level of enforcement and publicity regarding sobriety checkpoints is necessary to maintain effectiveness over time?

Server intervention training

• Are server intervention training programs delivered community-wide effective at decreasing alcohol-impaired driving and alcohol-related crashes?
• What essential content areas should be included in all server intervention training programs?
• What effect does the method by which training is delivered (e.g., videotapes, lectures, role-playing) have on the effectiveness of server training programs?
• How do mandatory vs. voluntary server training programs differ with respect to:
  • management support for program goals
  • level of participation in training programs
  • overall effectiveness for decreasing patron BACs and drinking and driving?
• What specific management policies and practices are necessary to get the maximum benefits from server intervention training?
• What is the long-term effect of server intervention training programs? Are “booster sessions”required to maintain effectiveness?
• What effect does server intervention training have on alcohol sales, overall revenues, and tips?

Applicability

These five interventions should be applicable in most target populations and settings. However, questions remain regarding possible differences in the effectiveness of each intervention for specific settings and subgroups. For example,

• Are these interventions equally effective in rural and urban settings?
• Are these interventions equally effective when applied to populations with different baseline levels of alcohol-impaired driving?
• Does targeting publicity efforts to specific subpopulations (e.g., young drivers, ethnic minorities, males) improve the effectiveness of interventions to reduce alcohol-impaired driving?

Other Positive or Negative Effects

Few other positive and negative effects were reported in this body of literature. Further research regarding the following questions would be useful:

• What proportion of youths charged with violating zero tolerance laws had BAC levels elevated enough to warrant a more serious drinking-driving offense?
• Do interventions to reduce alcohol-impaired driving reduce other forms of alcohol-related injury?

Economic Evaluations

Little economic evaluation information was available. Research is warranted to answer the basic economic questions: what are the cost-benefit, cost utility, and cost effectiveness of interventions to reduce alcohol-impaired driving?

Barriers to Implementation

Several of the interventions reviewed face barriers to effective implementation. Research into the following areas may help to overcome these barriers:

• What role can community coalitions play in removing barriers to implementing interventions designed to prevent alcohol-impaired driving?
• What are the most effective means of disseminating research findings about effectiveness to groups that want to implement interventions?
• What forms of incentives (e.g., insurance discounts) are most helpful for increasing management and owner support for server intervention training?
• How can the costs of interventions to prevent alcohol-impaired driving be shared or subsidized?
• What situational and environmental influences help or hinder the implementation of server intervention training?

Discussion

Interventions to prevent alcohol-impaired driving are implemented within the social and legal context of a community. Although these reviews evaluate each intervention as an independent activity, effective prevention of impaired driving requires a comprehensive and systematic approach that addresses various individual and ecological influences on drinking and driving behavior. These reviews can help decision makers identify and implement effective interventions that fit within an overall prevention strategy.

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Interventions to Increase Seat Belt Use

Effectiveness

There is strong evidence for the effectiveness of the three interventions reviewed. However, important research issues related to the effectiveness of these interventions remain.

Safety belt laws

• To what extent does the level of enforcement and publicity influence the effectiveness of safety belt laws?
• Does the severity of fines have any bearing on the effectiveness of the laws?
• Do other penalties (e.g., license demerits) add to the effectiveness of the laws?
• Do exemptions for certain vehicles and occupants reduce the effectiveness of the laws?

Primary safety belt laws

• What are the age, sex, and racial differences between violators in primary and secondary law states?
• Are primary enforcement laws more or less effective in certain populations?

Enhanced enforcement

• How does the length and frequency of enhanced enforcement programs influence their effectiveness?
• Does the effectiveness of enhanced enforcement programs vary based on the scale of the interventions (e.g., single community vs. multi-community programs)?
• How do publicity, public education, and news coverage affect enhanced enforcement programs?

Applicability

All three interventions appear to be effective in most populations and settings. Although some differences in effectiveness for subgroups have been identified in these reviews, other questions regarding differential effectiveness of these interventions remain.

• What penalties for violations of laws (e.g., fines, license demerits) are most effective among high-risk drivers (e.g., teenagers, drinking drivers)?
• What are the most effective methods of publicizing enhanced enforcement to reach high-risk drivers?

Other Positive or Negative Effects
Research on the positive and negative effects of each intervention might include:

• Do primary safety belt laws increase or decrease risky driving?
• Do enhanced enforcement programs for safety belt use decrease risky driving?
• Do primary laws or enhanced enforcement programs deter alcohol-impaired driving?
• Are primary laws associated with changes in frequency of traffic stops for ethnic and racial minorities relative to the general population?

Economic Evaluations

Little economic evaluation information was available. Research is warranted to answer the basic economic questions: what are the cost-benefit, cost utility, and cost effectiveness of interventions to increase safety belt use?

Barriers
A number of barriers impede effective implementation of each intervention reviewed. Research into the following areas may help to overcome these barriers.

• How can communities increase public acceptance of primary safety belt laws?
• Do enhanced enforcement programs divert police from other crimes?

Discussion
These reviews examined interventions to increase safety belt use among individuals over the age of 5 years. An accompanying article in the Nov. 2001 AJPM supplement addresses interventions to increase use of child safety seats by children aged 0-4 years. A clear gap in these two sets of reviews and in the Task Force's recommendations is for children who are too old or large to sit in child safety seats but who are too small to wear safety belts without the use of booster seats (generally children aged 4 to 8 years). The literature base regarding the efficacy of booster seats, and particularly that of population-based interventions to improve their use, is still emerging. Future updates of these reviews and recommendations should address this vulnerable population.

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Interventions to Increase the Use of Child Safety Seats

Effectiveness

For all five interventions reviewed, the team identified key research issues that had not been answered in the systematic review process. These research issues were grouped by the types of evidence sought. The team identified sufficient or strong evidence of effectiveness for four interventions (i.e., child safety seat laws, community-wide information and enhanced enforcement campaigns, distribution programs, and incentive programs). However, several important research issues regarding the effectiveness of these interventions remain.

Does effectiveness of the intervention change when specific elements are changed?
For example,

• Does the effectiveness of child safety seat laws vary depending on the requirements of different state laws?
• Does effectiveness of laws vary depending on the intensity and visibility of regular enforcement in the state?
• Would the threat of being charged with contributory negligence if an unrestrained child is killed or injured in a motor vehicle crash change the effectiveness of the law?
• What role does information about laws play in compliance rates?
• Are distribution programs sponsored by medical care organizations more or less effective than programs implemented by other organizations (e.g., insurance companies or community organizations)?
• Are low-cost rental programs any more or less effective than free loan programs?
• Are different incentives needed for different devices (e.g., infant safety seats, child seats, booster seats, safety belts)?
• What is the relative effectiveness of different incentives (e.g., direct rewards related to restraint use vs. chances to win prizes)?

What is the long-term effectiveness of each intervention? For example,

• How can the effectiveness of a child safety seat law be maintained over time?
• Can incentive programs improve long-term use of child safety seats? If so, what kind of reward schedule and distribution method is necessary to maintain positive effects?

How effective are various combinations of these four interventions? For example,

• Does enhanced enforcement provide marginal benefit to that provided by legislation?
• Do hospital discharge policies requiring that newborns be restrained in an approved device increase the effectiveness of distribution programs?

Because the effectiveness of education alone has not been established, basic research questions remain. For example,

• What amount and quality of content are necessary to improve knowledge, attitudes, and behaviors?
• What are appropriate educational contents and methods for delivery to children at various developmental stages?
• What are the appropriate outcomes to measure when educating young children about the use of child safety seats?
• Is education alone effective to:
  • increase parental use of child safety seats?
  • increase children's independent use of child safety seats?
  • increase enforcement of child safety seat laws by law enforcement officials?
  • encourage hospital personnel to develop and enforce policies regarding child safety seat use?

Other Positive and Negative Effects

The studies included in the reviews did not measure other positive and negative effects of the interventions. For all five interventions, research is needed to determine whether each intervention is likely to either increase or reduce misuse of child safety seats. Research is also needed to determine the role of community-wide or individual education in facilitating the effectiveness of other interventions (e.g., legislation, loaner programs).

Applicability

Each of the effective interventions should be applicable in most of the relevant target populations and settings. However, differences in the effectiveness of each intervention for specific subgroups of the population could not be determined. Several questions about the applicability of these interventions in settings and populations other than those studied remain. For example,

• Are these interventions equally effective in all populations within a state (e.g., racial and ethnic minorities, high- and low-income populations, or behavior change-resistant populations)?
• How must the content and methods of the educational components of interventions be altered to work in different populations?
• Are these interventions effective in populations that already have high baseline safety seat use rates?
• Do programs targeted at parents of infants improve the rate at which parents buy or use child safety seats for children older than one year?
• Are incentive programs effective in settings other than those studied (e.g., state motor vehicle inspection stations) or when implemented by other organizations (e.g., community groups or local businesses)?

Economic evaluations

The team did not identify any economic evaluation meeting Community Guide standards for these interventions. Thus, basic economic research must still be conducted:

• What is the cost of interventions to increase the use of child safety seats?
• Are interventions to increase the use of child safety seats cost-saving?
• What is the return on investment of interventions to increase child safety seat use?

Discussion

Systematic literature reviews are particularly useful for creating guidelines. The Task Force on Community Preventive Services has done this by using the evidence from these systematic reviews to make recommendations about the use of the interventions. Systematic reviews are also useful for identifying gaps in our knowledge base. The research questions provided in this article should be used to guide future research, both by government agencies and foundations in allocating research funding and by academic and other research organizations in determining research priorities.
Dissemination of these findings is ongoing through federal and state government agencies, advocacy organizations, and other groups with missions that include reducing child motor vehicle occupant injuries. Implementation advice for these interventions is available from several organizations, including the National Highway Traffic Safety Administration (www.nhtsa.gov), the National Center for Injury Prevention and Control of the Centers for Disease Control and Prevention (www.cdc.gov/ncipc), and the National SAFE KIDS Campaign (www.safekids.org).

An important implementation issue regarding distribution and education programs has arisen since the studies in this review were conducted. Because the integrity of child safety seats can be compromised in a crash, seats returned to a distribution and education program should not be lent to others because there can be no guarantee that they were not involved in a crash. Therefore, when implementing child safety seat distribution and education programs, only new, unused seats should be provided to all recipients.

These interventions are aimed at children aged 0-4 and their parents. All 50 states require children in this age group to be properly restrained while riding in motor vehicles. Accompanying articles in the November 2001 AJPM supplement addresses interventions to improve the use of safety belts among teenagers and adults. A clear gap in these two sets of reviews and in the Task Force's recommendations is for children who are too old or large to sit in child safety seats but who are too small to wear safety belts without the use of booster seats (generally children aged 4 to 8 years). The literature base regarding the efficacy of booster seats, and particularly for population-based interventions to improve their use, is still emerging. Future updates of these reviews and recommendations should address this vulnerable population.

Systematic reviews are limited to the information published in the existing studies. In the present reviews, for example, no studies discriminated between correct and incorrect use of child safety seats. Although some studies evaluated correct use only, they neither estimated incorrect use nor discussed how to correct mistakes in child safety seat installation or child restraint. Because estimates of misuse of child safety seats are so high, it is imperative to continue research on how to reduce misuse of child safety seats.

Finally, these reviews did not examine positioning of children within the car. Recent evidence has clearly shown a relationship between placement of rearward facing infant safety seats in the passenger seat of a car with an activated airbag and increased risk of death of the infant if the airbag is deployed. None of the studies included in the reviews examined the effect of the interventions on placement of the child safety seat in the rear seat of the car. This problem is largely due to the abundance of studies that predated either the widespread installation of airbags or the recognition of the danger of airbags to infants and children.

Although numerous questions remain, evidence is available about the effectiveness of four of the five strategies we reviewed. This scientific evidence, along with the accompanying recommendations of the Task Force, can be a powerful tool for securing the resources and commitment required to implement these strategies.