Commentary on Yao et al. (2016): Enforcement uniquely predicts reductions in alcohol-impaired crash fatalities

Determining a dosage threshold of drink-driving enforcement operations: A systematic review

ISSUES

Policy enforcement is crucial to achieve impacts on alcohol-related harm. It is not clear what level of enforcement intensity or 'dosage' is necessary for addressing drink driving and related harms. Given competing enforcement demands and agencies' resource constraints, understanding how much enforcement is sufficient to deter drink driving is critical.

APPROACH

This systematic literature review followed Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA) guidelines to examine research about dosage effects of enforcement and related visibility on drink-driving outcomes, including motor vehicle crashes and fatalities. Risk of bias was assessed using the Cochrane Collaboration Effective Practice and Organization of Care tool and the JBI checklist.

KEY FINDINGS

The 21 studies that met the inclusion criteria for this review differed in measures of enforcement dosage and outcomes, making it difficult to synthesise results across studies and draw conclusions about a threshold or optimal level of enforcement. Although most included studies found that sustained enforcement was associated with reductions in drink driving or related harms, only two studies tested an optimal dosage. Due to study design limitations, a substantial percentage of these studies must be considered with caution.

IMPLICATIONS

Additional research with rigorous study designs with appropriate controls is needed to determine an optimal high visibility enforcement dosage level to help law enforcement agencies make realistic decisions about allocating enforcement resources to address drink driving.

CONCLUSION

Consistent evidence about a drink-driving enforcement dosage threshold is lacking, partly due to an insufficient number of well-designed studies. Addressing challenges of conducting rigorous studies in community settings is crucial.

Drinking and driving and perceptions of arrest risk among California drivers: Relationships with DUI arrests in their city of residence

OBJECTIVE

Addressing drinking and driving remains a challenge in the United States. The present study aims to provide feedback on driving under the influence (DUI) in California by assessing whether drinking and driving behavior is associated with the DUI arrest rates in the city in which the driver lives; whether this is due to perceptions that one can get arrested for this behavior; and whether this differed by those drivers who would be most affected by deterrence efforts (those most likely to drink outside the home).

METHODS

This study consisted of a 2012 roadside survey of 1,147 weekend nighttime drivers in California. City DUI arrest rates for 2009-2011 were used as an indicator of local enforcement efforts. Population average logistic modeling was conducted modeling the odds of perceived high arrest likelihood for DUI and drinking and driving behavior within the past year.

RESULTS

As the DUI arrest rates for the city in which the driver lives increased, perceived high risk of DUI arrest increased. There was no significant relationship between either city DUI arrest rates or perceived high risk of DUI arrest with self-reported drinking and driving behavior in the full sample. Among a much smaller sample of those most likely to drink outside the home, self-reported drinking and driving behavior was negatively associated with DUI arrests rates in their city of residence but this was not mediated by perceptions.

CONCLUSION

The results of the present study suggest that perceptions are correlated with one aspect of DUI efforts in one's community. Those who were more likely to drink outside the home could be behaviorally influenced by these efforts.