Dosage of Policy Enforcement Interventions and Community Alcohol Problems

ABSTRACTProblems associated with alcohol affect individuals, families and communities. Alcohol-related community problems include underage and excessive drinking, driving under the influence (DUI) crashes and injuries, violence, crime and negative effects on quality of life. Policy interventions to reduce and prevent community-level alcohol-related problems have been the focus of much research, resulting in the recognition of effective and promising prevention practices. Alcohol policies include laws: establishing a maximum blood alcohol concentration (BAC) allowed for driving, a minimum age for purchase and consumption of alcohol; and limiting sales to underage or intoxicated persons. Policy enforcement can deter DUI, sales of alcohol to underage or intoxicated persons, underage and excessive drinking, especially if the enforcement is highly visible to the public. A growing body of literature examines the amount and frequency, or “dosage” of interventions that is associated with improved health or reductions in problems. Much of the dosage research involves educational or treatment interventions that focus on individual or group behavior change, rather than on policy interventions designed to make change at the community level. The overarching goals of this dissertation research are to: 1) examine the existing alcohol policy enforcement literature; 2) explore certain community factors that may be associated with higher levels of dosage; and 3) compare how varying levels of alcohol policy enforcement dosage affect community alcohol-related outcomes.Paper 1 examines research literature regarding the association between dosage of high-visibility alcohol policy enforcement and alcohol-related problems at the community level. A systematic review found support for consistent enforcement to achieve desired alcohol-related outcomes, and for “high” versus “low” levels of enforcement. However, there was no consensus found among the studies for a necessary threshold of enforcement dosage, due in part to the differences in problems addressed, existing policies in study communities, types of enforcement interventions used, and the designs and sizes of the studies. Findings support the need for additional research with rigorous study designs to determine effective levels of dosage of high-visibility alcohol policy enforcement. Paper 2 investigates the association between dosage of high-visibility alcohol enforcement interventions and: level of alcohol problems at baseline, interagency collaboration, and additional grant funding from two state agencies, in 12 intervention cities funded by the California Strategic Prevention Framework State Incentive Grant (SPF SIG). Multi-level modeling is used to study the effects of these three community characteristics on levels of dosage over 12 months. Findings indicate that funding may lead to more high-visibility enforcement to reduce crashes, injury, and mortality associated with driving under the influence (DUI). Interagency collaboration may lead to more enforcement and visibility to reduce retail availability of alcohol (e.g., at convenience stores) to underage persons. Baseline levels of alcohol-related problems were not found to be significantly associated with higher levels of enforcement. None of the community characteristics studied here was significantly associated with higher levels of enforcement to reduce social availability of alcohol (e.g., at parties). Future studies that include larger samples of cities are needed to help explain how these and other community factors may influence implementation of high-visibility alcohol enforcement interventions.Paper 3 focuses on the effects of four levels of dosage (zero, low, medium, and high) of a high-visibility DUI enforcement intervention on changes over 58 months in the proportion of DUI crashes and DUI injury crashes in the 24 cities of the California SPF SIG project. Multi-level modeling is used to examine the moderating effect of dosage level on the relationship between time and DUI crash and injury rates. Findings reveal a statistically significant moderating effect of medium dosage level (i.e., approximately 1 intervention per month) on the negative relationship between time and DUI crashes. Although not statistically significant, a high level of dosage is associated with an increase in the proportion of DUI crashes, while a low dosage level results in no change in the proportion of DUI crashes. Statistically significant moderating effects of both medium and high dosage levels are found on the negative relationship between time and injury DUI crashes. These findings suggest that implementing approximately 1 DUI enforcement intervention per month may be best for reducing both DUI crashes and DUI injury crashes, and that a higher number of interventions per month does not lead to better outcomes. Replication can help strengthen these findings, and may lead to practical policy enforcement recommendations for communities to reduce DUI injuries and related crashes