CDC Guide for Measuring Alcohol Outlet Density
CDC developed the Guide for Measuring Alcohol Outlet Density to help public health practitioners measure alcohol outlet density – which is a key risk factor for levels of alcohol use and related harm – at state and local levels.
This Guide discusses the importance of measuring alcohol outlet density and different approaches for doing so, along with their pros and cons.
Alcohol use is responsible for 88,000 deaths annually in the United States, including 1 in 10 deaths among working-age adults aged 20 to 64 years, costing the United States $249 billion in 2010, or $2.05 per drink. Binge alcohol use, or four or more drinks per occasion for women and five or more drinks per occasion for men, is responsible for more than half the deaths and three-quarters of the costs caused by alcohol. Yet, 9 in 10 adult excessive alcohol users are not alcohol-dependent.
High alcohol outlet density, defined as a high concentration of retail alcohol outlets in a small area, is known to be an environmental risk factor for alcohol use. To prevent harmful use of alcohol, the Community Preventive Services Task Force recommends “limiting alcohol outlet density through the use of regulatory authority (e.g., licensing and zoning),” which is based on strong scientific evidence of intervention effectiveness.
Alcohol outlet density varies widely among states and communities. Therefore, public health surveillance is needed to assess alcohol outlet density and to guide the development of public health interventions for reducing alcohol outlet density. For example, a liquor control agency could use information about alcohol outlet density to limit the issuance of new alcohol licenses, or to increase enforcement of liquor laws in a particular area. Information about alcohol outlet density could also be used by local governments to develop zoning regulations to regulate alcohol outlet density. In addition, public health surveillance of alcohol outlet density can be used to evaluate the relationship between exposure to retail alcohol outlets and various alcohol- attributable harms, such as property damage and interpersonal violence, as well as to evaluate the effects of reducing alcohol outlet density on these harmful outcomes.
There are several steps for measuring alcohol outlet density, including defining the reason for measuring alcohol outlet density, the measurement area, and the type of measure that will be used. In addition, it is necessary to:
- Obtain data about licensed alcohol outlets in the area
- Categorize retail alcohol outlets by type (e.g., on-premises or off-premises)
- Select the type(s) of alcohol outlet(s) that will be included in the assessment
- Geocode the alcohol outlets in the measurement area (i.e., assign geographic coordinates [latitude and longitude] to the alcohol outlets)
- Calculate alcohol outlet density using the selected approach.
There are three main approaches for measuring alcohol outlet density:
Each approach has advantages and disadvantages that should be carefully considered when selecting a measurement strategy, while being mindful of how the results will be used. In addition, there are many community characteristics (e.g., whether a community is located in an urban or rural area) that should be considered when selecting an alcohol outlet density measurement strategy.
Any measurement of outlet density is better than none, provided one is fully aware of the limitations of the measurement approach that is being used. As one moves from container-based to distance-based to spatial access-based measures of alcohol outlet density, the completeness and specificity of the measures increase, as does the complexity of the measurement process and resource requirements. If the resources are available, distance or spatial access-based measures of alcohol outlet density offer many advantages over container-based measures because they are not constrained by existing geopolitical boundaries. In addition, distance or spatial access-based measures allow for the assessment of alcohol outlet clustering, which is known to be associated with an increased risk of alcohol use and related harms, such as violent crime.
Based on a systematic review of scientific evidence on the effectiveness of regulating alcohol outlet density that was done for The Guide to Community Preventive Services (Community Guide), as well as other scientific studies, there is strong scientific evidence that regulating alcohol outlet density is one of the most effective strategies for reducing alcohol consumption and related harms.
Thus, assessing and monitoring alcohol outlet density are essential for public health agencies to help guide the development of strategies that regulate this environmental risk factor. In addition, developing and implementing other evidence-based strategies to prevent excessive alcohol use (e.g., the enforcement of liquor laws, such as the age 21 minimum legal age) are needed.
The information in this guide can help state and local health departments measure this environmental risk factor, and thus, guide the regulation of alcohol outlet density at state and local levels.
Monitoring environmental health hazards, such as high alcohol outlet density, is an essential public health function. Accordingly, public health agencies should consider collecting and reporting alcohol outlet densities within their jurisdiction consistently to help guide the development of effective strategies for preventing excessive alcohol consumption and related harms. Towards this end, any measurement of alcohol outlet density is better than none, as long as one is fully aware of the limitations of the measurement approach that is being used.
Consider the pros and cons of different measurement strategies carefully, being mindful of how these data will be used. As one moves from container-based, to distance-based, to spatial access-based measures of alcohol outlet density, the completeness and specificity of the measures increase, along with the complexity and resource requirements. However, distance or spatial access-based measures of alcohol outlet density offer many advantages over predefined, container-based measures because they are not constrained by existing geopolitical boundaries. In addition, distance or spatial access-based measures allow for the assessment of alcohol outlet clustering, which is known to be associated with an increased risk of alcohol use and related harms (e.g., violent crime). A spatial access-based measure can also be weighted to account for differences in the size of the resident population and, if a census-based unit is used, adjusted to account for other differences in the demographic characteristics (e.g., age, race, socioeconomic status) of the exposed population. This weighting can also allow for comparisons between small geographic areas with high alcohol outlet densities.
If resources are limited, and the goal is simply to get an overall estimate of exposure to retail alcohol outlets within a specified geographic area (e.g., a city or county), then a container-based approach (e.g., an assessment of the number of alcohol outlets per square mile) may be sufficient. However, container-based measures can also be significantly affected by changes in the resident population (e.g., increases or decreases in total population); changes in usable land area; availability of public transportation; and other factors, depending on the measure that is chosen. These factors can undermine the usefulness of these measures for assessing changes in alcohol outlet density over time. It is also not possible to adjust for small-area variations in population size and population characteristics. These limitations can make it difficult to compare alcohol outlet densities within a city, county, or state. Therefore, container-based approaches to measuring alcohol outlet density should only be used if no other option is available.
Standardized concepts and measurement strategies are needed to assess changes in alcohol outlet density over time, compare alcohol outlet densities in different areas, and provide a basis for assessing the relationship between alcohol outlet density and alcohol-attributable harms. Guidelines and criteria are also needed for defining the threshold values for an area with high alcohol outlet density. Additional research is needed to further describe the validity and reliability of various alcohol outlet density measurement strategies and the level of agreement between alcohol outlet density measures calculated by using different measurement strategies. Furthermore, assessing how the risk of alcohol-attributable harms varies based on the distance between alcohol outlets needs more study. Further research is also needed to examine whether there is a tipping point for alcohol outlet density beyond which the risk of alcohol-attributable harms increases substantially, and if so, whether this tipping point varies based on the sociodemographic characteristics of communities where retail alcohol outlets are located.
However, from the Community Guide review and other scientific studies, there is strong scientific evidence to support that regulating alcohol outlet density is one of the most effective strategies for reducing alcohol consumption and related harms.
Consequently, it is essential for public health agencies to assess alcohol outlet density to help guide the development of strategies to regulate this environmental risk factor, and to support the design and implementation of other evidence-based strategies for preventing excessive alcohol use and related harms.