Motor Vehicle Injury Alcohol-Impaired Driving: Maintaining Current Minimum Legal Drinking Age (MLDA) Laws

The CPSTF finding is based on evidence from a systematic review of 33 studies (search period 1966 – 2000).

The review was conducted on behalf of the CPSTF by scientists from CDC’s Division of Unintentional Injury Prevention with input from a team of specialists in systematic review methods and experts in research, practice and policy related to motor vehicle injury prevention.

As of February 2017, all 50 states had set their minimum legal drinking age laws at 21. Some states allow youth to consume alcohol in certain situations, for example during religious ceremonies or when parents give permission.

More details about study results are available in the published evidence review.

The systematic review included 33 studies.

• Most of the studies assessed the effects of changes in the MLDA from ages 18 to 21 or vice versa.
  • Effects of raising the MLDA: crash-related outcomes decreased by a median of 16% (14 studies; 1 study evaluating fatal crashes among 16-17 year olds was not included in the summary effect measures)
  • Effects of lowering the MLDA: crash-related outcomes increased by median of 10% (9 studies)
  • Estimated effect of raising the MLDA by 3 years (from 18 to 21) from regression-based studies: crash-related outcomes decreased by a median of 12% (9 studies)
• Effects were stable over follow-up times ranging from 7 months to 9 years.

An economic review of this intervention did not find any relevant studies.

• Results should be applicable to all drivers 18 20 years of age.
• Results are based on studies from the United States, Australia, and Canada. They may not apply to countries with different alcohol consumption or driving patterns.

CPSTF identified several areas that have limited information. Additional research and evaluation could help answer the following questions and fill remaining gaps in the evidence base. (What are evidence gaps?)

• How do variations in enforcement levels influence the effectiveness of MLDA laws?
• What are the independent effects of publicity on the effectiveness of MLDA laws?
• Does public compliance with new laws change in a predictable manner over time?
• How do interventions to reduce alcohol-impaired driving interact with each other (e.g., 0.08% BAC laws and administrative license revocation)?
• What effects do these interventions have on long-term changes in social norms about drinking and driving?
• Are interventions equally effective in rural and urban settings?
• Are interventions equally effective when applied to populations with different baseline levels of alcohol-impaired driving?
• Do MLDA laws reduce other forms of alcohol-related injury?
• What are the cost-benefit, cost utility, and cost-effectiveness of interventions to reduce alcohol impaired driving?
• What role can community coalitions play in maintaining MLDA laws?

• Studies were conducted in the United States, Australia, and Canada.
• Most studies in the review assessed the effect of changes in the minimum legal drinking age from 18 to 21 years or vice versa.
• Included studies reported the following outcomes: fatal injury crashes or crash fatalities; fatal and nonfatal injury crashes; or other crash types.

Effectiveness Review

Analytic Framework see Figure 1 on page 67

When starting an effectiveness review, the systematic review team develops an analytic framework. The analytic framework illustrates how the intervention approach is thought to affect public health. It guides the search for evidence and may be used to summarize the evidence collected. The analytic framework often includes intermediate outcomes, potential effect modifiers, potential harms, and potential additional benefits.

Effectiveness Review

Summary Evidence Table

The number of studies and publications do not always correspond (e.g., a publication may include several studies or one study may be explained in several publications).

Effectiveness Review

Brown DB, Maghsoodloo SA. A study of alcohol involvement in young driver accidents with the lowering of the legal age of drinking in Alabama. Accid Anal Prev 1981;13:319 22.

Cook PJ, Tauchen G. The effect of minimum drinking age legislation on youthful auto fatalities. J Legal Stud 1984;13:169 90.

Chaloupka FJ, Saffer H, Grossman M. Alcohol control policies and motor vehicle fatalities. J Legal Stud 1993;22:161 86.

Dee TS. State alcohol policies, teen drinking and traffic fatalities. J Public Econ 1999;72:289 315.

Decker MD, Graitcer PL, Schaffner W. Reduction in motor vehicle fatalities associated with an increase in the minimum drinking age. JAMA 1988;260: 3604 10.

DuMouchel W, Williams AF, Zador P. Raising the alcohol purchase age: its effects on fatal motor vehicle crashes in twenty-six states. J Legal Stud 1987;16:249 66.

Durant R, Legge JS. Policy design, social regulation and theory building: lessons from the traffic safety policy arena. Political Res Q 1993;46:641 56.

Ferreira J, Sickerman A. The impact of Massachusetts reduced drinking age on auto accidents. Accid Anal Prev 1976;8:229 39.

Figlio DN. Effect of drinking age laws and alcohol-related crashes: timeseries evidence from Wisconsin. J Policy Anal Manage 1995;14:555 66.

Hingson R, Scotch N, Mangione T, et al. Impact of legislation raising the legal drinking age in Massachusetts from 18 to 20. Am J Public Health 1983;73:163 9.

Hoskin AF, Yalung Mathews D, Carraro BA. Effect of raising the legal minimum drinking age on fatal crashes in 10 states. J Safety Res 1986;17: 117 21.

Legge J Jr. Reforming highway safety in New York State: an evaluation of alternative policy interventions. Soc Sci Q 1990;71:373 82.

Lillis R, Williams T, Williford W. The impact of the 19-year-old drinking age in New York. Advances in Substance Abuse 1987;Suppl 1, Control Issues in Alcohol Abuse Prevention: Strategies for States and Communities:133 46.

Males M. Minimum purchase age for alcohol and young-driver fatal crashes: a long-term view. J Legal Stud 1986;15:181 211.

Naor EM, Nashold RD. Teenage driver fatalities following reduction in the legal drinking age. J Safety Res 1975;7:74 9.

O’Malley PM, Wagenaar AC. Effects of minimum drinking age laws on alcohol use, related behaviors and traffic crash involvement among American youth: 1976 1987. J Stud Alcohol 1991;52:478 91.

Ruhm CJ. Alcohol policies and highway vehicle fatalities. J Health Econ 1996;15:435 54.

Saffer H, Chaloupka F. Breath testing and highway fatality rates. Appl Econ 1989;21:901 12.

Saffer H, Grossman M. Beer taxes, the legal drinking age, and youth motor vehicle fatalities.J Legal Stud 1987;16:351 74.

Saffer H, Grossman M. Drinking age laws and highway mortality rates: cause and effect. Econ Inquiry 1987;25:403 17.

Smith DI, Burvill PW. Effect on traffic safety of lowering the drinking age in three Australian states. J Drug Issues 1986;16:183 98.

Smith RA, Hingson RW, Morelock S, et al. Legislation raising the legal drinking age in Massachusetts from 18 to 20: effect on 16 and 17 year olds. J Stud Alcohol 1984;45:534 9.

Voas RB, Tippetts AS, Fell J. The United States limits drinking by youth under age 21: Does this reduce fatal crash involvements? 43rd Annual Proceedings Association for the Advancement of Automotive Medicine, September 20 21, 1999. Barcelona (Sitges), Spain. pp. 265 78.

Wagenaar AC. Preventing highway crashes by raising the legal minimum age for drinking: the Michigan experience 6 years later. J Safety Res 1986;17:101 9.

Wagenaar AC. Raising the legal drinking age in Maine: impact on traffic accidents among young drivers. Int J Addict 1983;18:365 77.

Wagenaar AC, Maybee R. Legal minimum drinking age in Texas: effects of an increase from 18 to 19. J Safety Res 1986;17:165 78.

Whitehead PC, Craig J, Langford N, MacArthur C, Stanton B, Ferrence RG. Collision behavior of young drivers: impact of the change in the age of majority. J Stud Alcohol 1975;36:1208 23.

Williams AF, Rich RF, Zador PL. The legal minimum drinking age and fatal motor vehicle crashes. J Legal Stud 1975;4:219 39.

Williams AF, Zador PL, Harris SS, Karpf RS. The effect of raising the legal minimum drinking age on involvement in fatal crashes. J Legal Stud 1983;12:169 79.

Womble K. Impact of minimum drinking age laws on fatal crash involvements: an update of the NHTSA analysis. J Traffic Safety Educ 1989;37:4 5.

The following outlines the search strategy used for reviews of these interventions to reduce alcohol-impaired driving: 0.08% Blood Alcohol Concentration (BAC) Laws; Lower BAC Laws for Young or Inexperienced Drivers; Maintaining Current Minimum Legal Drinking Age (MLDA) Laws; Mass Media Campaigns; Multicomponent Interventions with Community Mobilization; Ignition Interlocks; School-Based Programs; Designated Driver Promotion Programs; Sobriety Checkpoints (archived); Intervention Training Programs for Servers of Alcoholic Beverages (archived).

The reviews of interventions to reduce motor vehicle-related injury reflect systematic searches of multiple databases as well as reviews of reference lists and consultations with experts in the field. The team searched six computerized databases (MEDLINE, Embase, Psychlit, Sociological Abstracts, EI Compendex, and Transportation Research Information Services [TRIS]), which yielded 10,958 titles and abstracts for articles, book chapters, reports, and published papers from the Association for the Advancement of Automotive Medicine proceedings about safety belts, alcohol-impaired driving or child passenger safety. Studies were eligible for inclusion if:

• They were published from the originating date of the database through June 2000 (March 1998 for child safety seat interventions)
• They involved primary studies, not guidelines or reviews
• They were published in English
• They were relevant to the interventions selected for review
• The evaluation included a comparison to an unexposed or less-exposed population
• The evaluation measured outcomes defined by the analytic framework for the intervention

For alcohol-impaired driving reviews, supplementary searches were conducted to address specialized questions and to update searches for reviews published after 2001. The final search using the primary alcohol-impaired driving search strategy was conducted through December 2004. For the most recent review in this series, “Effectiveness of Multicomponent Programs with Community Mobilization for Reducing Alcohol-Impaired Driving,” this database was supplemented by a hand search of the “Alcohol and Other Drugs” and “Transportation” sections of the SafetlyLit injury literature update service for the period from January through June 2005.

Effectiveness Review

Primary Search Strategy

1. S MOTOR(W)VEHICLE? OR CAR OR CARS OR AUTOMOBILE? OR MOTORCYCLE? OR TRUCK? OR TRAFFIC(2N)ACCIDENT? OR DRIVING OR DRIVER?
2. S ALCOHOL OR ALCOHOLIC(W)BEVERAGE? OR ALCOHOL(3N)DRINKING OR ETHANOL OR ALCOHOLISM OR DWI OR DUI OR (DRIVING(3N)(INTOXICATED OR INFLUENCE OR DRUNK OR DRINKING OR IMPAIRED))
3. S INTERVENTION? OR OUTREACH? OR PREVENTION OR (COMMUNITY(3N)(RELATION? OR PROGRAM? OR ACTION)) OR DETERRENT? OR PROGRAM? OR LEGISLATION OR LAW? OR EDUCATION OR DETERENCE OR COUNSELING OR CLASS OR CLASSES OR HEALTH(W)PROMOTION
4. S FOOD(W)INDUSTRY OR AIRPLANE? OR AIRCRAFT? OR PILOT? OR SOLVENT? OR SLEEP(W)APNEA OR EMISSION? OR AIR(W)QUALITY OR POLLUTION
5. S (S1 AND S2 AND S3 ) NOT S4

Higher Education-based Interventions

S1 MOTOR(W)VEHICLE? OR CAR OR CARS OR AUTOMOBILE? OR MOTORCYCLE? OR TRUCK? OR TRAFFIC(2N)ACCIDENT? OR DRIVING OR DRIVER?
S2 ALCOHOL OR ALCOHOLIC(W)BEVERAGE? OR ALCOHOL(3N)DRINKING OR ETHANOL OR ALCOHOLISM OR DWI OR DUI OR (DRIVING(3N)(INTOXICATED OR INFLUENCE OR DRUNK OR DRINKING OR IMPAIRED))
S3 UNIVERSIT? OR COLLEGE? OR CAMPUS? OR (EDUCATION?(2N)(HIGER OR INSTITUTION? OR FACILIT? OR PROGRAM? OR SURVEY?))
S4 S1 AND S2 AND S3
S5 CURRICULUM OR INSTRUCTION OR EDUCATION OR TRAINING OR WORKSHOPS OR PROGRAMS OR COURSE? OR TEACH? OR (SOCIAL(W)NORM?)
S6 STUDENT? OR YOUTH? OR TEEN? OR (YOUNG(W)ADULT?)
S7 S4 AND S5 AND S6

School-based Interventions

S1 MOTOR(W)VEHICLE? OR CAR OR CARS OR AUTOMOBILE? OR MOTORCYCLE? OR TRUCK? OR TRAFFIC(2N)ACCIDENT? OR DRIVING OR DRIVER?
S2 ALCOHOL OR ALCOHOLIC(W)BEVERAGE? OR ALCOHOL(3N)DRINKING OR ETHANOL OR ALCOHOLISM OR DWI OR DUI OR (DRIVING(3N)(INTOXICATED OR INFLUENCE OR DRUNK OR DRINKING OR IMPAIRED))
S3 SCHOOL?(5N)(BASED OR SETTING OR PROGRAM? OR PRIMARY OR ELEMENTARY OR SECONDARY OR ((JUNIOR OR SENIOR)(W)HIGH) OR MIDDLE) OR (EDUCATION?(2N)(INSTITUTION? OR FACILIT? OR PROGRAM? OR SURVEY?))
S4 S1 AND S2 AND S3
S5 CURRICULUM OR INSTRUCTION OR EDUCATION OR TRAINING OR WORKSHOPS OR PROGRAMS OR COURSE? OR TEACH?
S6 STUDENT? OR ADOLESCENT? OR YOUTH? OR TEEN? OR CHILD? OR TEACHER?
S7 525 S4 AND S5 AND S6

Cost Analyses

1. S MOTOR(W)VEHICLE? OR CAR OR CARS OR AUTOMOBILE? OR MOTORCYCLE? OR TRUCK? OR TRAFFIC(2N)ACCIDENT? OR DRIVING OR DRIVER?
2. S ALCOHOL OR ALCOHOLIC(W)BEVERAGE? OR ALCOHOL(3N)DRINKING OR ETHANOL OR ALCOHOLISM OR DWI OR DUI OR (DRIVING(3N)(INTOXICATED OR INFLUENCE OR DRUNK OR DRINKING OR IMPAIRED))
3. S INTERVENTION? OR OUTREACH? OR PREVENTION OR COMMUNITY(3N)(RELATION? OR PROGRAM? OR ACTION)) OR DETERRENT? OR PROGRAM? OR LEGISLATION OR LAW? OR EDUCATION OR DETERENCE OR COUNSELING OR CLASS OR CLASSES OR HEALTH(W)PROMOTION
4. S FOOD(W)INDUSTRY OR AIRPLANE? OR AIRCRAFT? OR PILOT? OR SOLVENT? OR SLEEP(W)APNEA OR EMISSION? OR AIR(W)QUALITY OR POLLUTION
5. S COST? OR ECONOMIC? OR ECONOMETRIC?
6. S (S1 AND S2 AND S3 AND S5) NOT S4

The following considerations are drawn from studies included in the evidence review, the broader literature, and expert opinion. The Community Guide does not conduct systematic reviews of implementation considerations.

• Engage partners throughout the process. Building support from the ground up can help secure policies that reinforce healthy behaviors in the community.
• Demonstrate why the policy is important. Use CPSTF findings and recent surveillance data to show partners how policies have been effective.
• Educate stakeholders. Keep the media, community influencers, and policymakers informed about MLDA laws to help communicate messages that are accurate and timely.
  • Keep messages brief and to the point. Use graphics, figures, or infographics to clearly demonstrate how the intervention can improve health outcomes.
  • Extend communication reach by working through partners who have the most credibility with key audiences.
• Pay attention to sustainability. Continue to conduct surveillance related to alcohol-impaired driving and disseminate findings.

Healthy People 2030

Healthy People 2030 includes the following objectives related to this CPSTF recommendation.

• Reduce the proportion of motor vehicle crash deaths that involve a drunk driver — SU‑11