title: Ignition Interlock Laws: Effects on Fatal Motor Vehicle Crashes, 1982-2013.
abstract: BACKGROUND
  Alcohol-involved motor vehicle crashes are a major cause of preventable mortality in the U.S., leading to more than 10,000 fatalities in 2013. Ignition interlocks, or alcohol-sensing devices connected to a vehicle's ignition to prevent it from starting if a driver has a predetermined blood alcohol content (BAC) level, are a promising avenue for preventing alcohol-involved driving. This study sought to assess the effects of laws requiring ignition interlocks for some or all drunk driving offenders on alcohol-involved fatal crashes.
  
  
  METHODS
  A multilevel modeling approach assessed the effects of state interlock laws on alcohol-involved fatal crashes in the U.S. from 1982 to 2013. Monthly data on alcohol-involved crashes in each of the 50 states was collected in 2014 from the National Highway Traffic Safety Administration Fatality Analysis Reporting System. Random-intercept models accounted for between-state variation in alcohol-involved fatal crash rates and autocorrelation of within-state crash rates over time. Analysis was conducted in 2015.
  
  
  RESULTS
  State laws requiring interlocks for all drunk driving offenders were associated with a 7% decrease in the rate of BAC >0.08 fatal crashes and an 8% decrease in the rate of BAC ≥0.15 fatal crashes, translating into an estimated 1,250 prevented BAC >0.08 fatal crashes. Laws requiring interlocks for segments of high-risk drunk driving offenders, such as repeat offenders, may reduce alcohol-involved fatal crashes after 2 years of implementation.
  
  
  CONCLUSIONS
  Ignition interlock laws reduce alcohol-involved fatal crashes. Increasing the spread of interlock laws that are mandatory for all offenders would have significant public health benefit.
authors.affiliation: Center for Injury Research and Policy and Center for Mental Health and Addiction Policy Research, Department of Health Policy and Management, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland. Electronic address: bmcginty@jhu.edu.
authors.forename: Emma E
authors.initials: EE
authors.lastname: McGinty
authors.affiliation: Department of Health Systems, Management and Policy, Program for Injury Prevention, Education and Research (PIPER), Colorado School of Public Health, Aurora, Colorado.
authors.forename: Gregory
authors.initials: G
authors.lastname: Tung
authors.affiliation: Center for Injury Research and Policy, Department of Health Policy and Management, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland.
authors.forename: Juliana
authors.initials: J
authors.lastname: Shulman-Laniel
authors.affiliation: Department of Health Systems, Management and Policy, Program for Injury Prevention, Education and Research (PIPER), Colorado School of Public Health, Aurora, Colorado.
authors.forename: Rose
authors.initials: R
authors.lastname: Hardy
authors.affiliation: Center for Injury Research and Policy, Department of Health Policy and Management, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland.
authors.forename: Lainie
authors.initials: L
authors.lastname: Rutkow
authors.affiliation: Center for Injury Research and Policy, Department of Health Policy and Management, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland.
authors.forename: Shannon
authors.initials: S
authors.lastname: Frattaroli
authors.affiliation: Center for Injury Research and Policy, Department of Health Policy and Management, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland.
authors.forename: Jon S
authors.initials: JS
authors.lastname: Vernick
mesh_terms: D000063:Accidents, Traffic / Q000401:mortality / Q000517:prevention & control* / Q000639:trends; D000066448:Driving Under the Influence / Q000331:legislation & jurisprudence* / Q000517:prevention & control; D006801:Humans; D011482:Protective Devices / Q000706:statistics & numerical data; D014481:United States