Evidence of a structural effect for alcohol outlet density: a multilevel analysis.

BACKGROUND: Ecological studies reveal that alcohol-related outcomes tend to occur in high alcohol outlet density neighborhoods. The ecological design of these studies limits the interpretation of the findings in terms of the level of the effect. The effect of alcohol outlet density could be related to greater individual access to alcohol, an individual level effect, or to the grouping of drinkers by neighborhood, a structural effect at the neighborhood level. METHODS: To differentiate between individual and neighborhood level possibilities, we conducted a multilevel study. Individual distance to the closest alcohol outlet was the individual level measure of the effect of alcohol outlet density, whereas the mean distance to the closest alcohol outlet for all individuals within a census tract was the neighborhood level measure for the effect of alcohol outlet density. We analyzed telephone surveys of 2604 telephone households within 24 census tracts stratified by poverty status and alcohol outlet density. Individual distance to alcohol outlets, age, sex, race/ethnicity, and level of education were entered as individual level covariates, and their corresponding aggregated means were entered as census tract level covariates (i.e., mean distance to outlets, mean age, percentage male, percentage Black, mean education). RESULTS: Analysis of variance revealed that 16.2% of the variance in drinking norms and 11.5% of the variance in alcohol consumption were accounted for at the census tract level. In multivariate hierarchical analysis, individual distance to the closest alcohol outlet was unrelated with drinking norms and alcohol consumption, whereas mean distance to the closest alcohol outlet demonstrated a negative relation with drinking norms (betae = -5.50+/-2.37) and with alcohol consumption (betae = -0.477+/-0.195); that is, the higher the mean distance to the closest alcohol outlet, the lower the mean drinking norms score and mean level of alcohol consumption. CONCLUSIONS: The findings suggest that the effect of alcohol outlet density on alcohol-related outcomes functions through an effect at the neighborhood level rather than at the individual level. Problem drinkers tend to be grouped in neighborhoods, an effect predicted by alcohol outlet density.

A structural model of health behavior: a pragmatic approach to explain and influence health behaviors at the population level.

BACKGROUND: Behavior is influenced by individual-level attributes as well as by the conditions under which people live. Altering policies, practices, and the conditions of life can directly and indirectly influence individual behavior. This paper builds on existing ecological theories of health behavior by specifying structural mechanisms by which population-level factors effect change in individual health behaviors. METHODS: This paper moves ecological theory from model building to a pragmatic characterization of structural interventions. We examined social and environmental factors beyond individual control and mechanisms as to how they influence behavior. RESULTS: Four categories of structural factors are identified: (1) availability of protective or harmful consumer products, (2) physical structures (or physical characteristics of products), (3) social structures and policies, and (4) media and cultural messages. The first three can directly influence individuals through facilitating or constraining behavior. The fourth, media, operates by changing individual-level attitudes, beliefs, and cognitions, as well as group norms. CONCLUSION: Interventions that target the four identified structural factors are a means to provide conditions that not only reduce high-risk behavior but also prevent the adoption of high-risk behaviors. Structural interventions are important and underutilized approaches for improving our nation's health.

A geographic relation between alcohol availability and gonorrhea rates.

BACKGROUND AND OBJECTIVES: The availability of alcohol measured as alcohol outlet density is associated with numerous alcohol-related outcomes in small area analysis. A number of studies suggest that high-risk sexual behavior should also be considered an alcohol-related outcome. GOAL OF THIS STUDY: To assess the geographic relationship between alcohol availability and high-risk sexual behavior at the neighborhood level. STUDY DESIGN: Ecological analysis of the geographic relation between off-premise, on-premise, and total alcohol outlet density and reported gonorrhea rates among 155 urban residential census tracts in New Orleans during 1995. RESULTS: All alcohol outlet density variables were positively related to gonorrhea rates. Off-premise outlets per square mile was most strongly related to gonorrhea rates (beta +/- SE) (beta = 0.582+/-0.073), accounting for 29% of the variance in gonorrhea rates. Interpreted as an elasticity, a 10% increase in off-sale alcohol outlet density accounts for a 5.8% increase in gonorrhea rates. Including the covariates percent black and percent unemployed to the model reduced but did not remove the effect of off-sale outlet density (beta = 0.192+/-0.047). CONCLUSIONS: These results indicate there is a geographic relationship between alcohol outlet density and gonorrhea rates at the census tract level. Although these results cannot be interpreted causally, they do justify a public health intervention as a next step in defining the relation between alcohol availability and high-risk sexual behavior.

Dietary calcium, calcium supplementation, and blood pressure in African American adolescents.

BACKGROUND: Intake of calcium from the diet is inversely associated with blood pressure in observational studies and animal models but randomized trials in humans have found only small effects of calcium supplementation on blood pressure. A blood pressure-lowering effect of calcium supplementation may thus be restricted to persons with a low intake of calcium from the diet and specific genetic or other characteristics. OBJECTIVE: A randomized trial was conducted to assess the effect of calcium supplementation on blood pressure in African American adolescents. Rapid growth during adolescence may increase calcium requirements, and avoidance of milk and milk products by some African Americans can result in low intake of calcium. DESIGN: One hundred sixteen adolescents (65 girls, 51 boys; mean age: 15.8 y) were given calcium (1.5 g/d) or placebo for 8 wk in a randomized, double-blind, crossover design. Blood pressure was measured after 2, 4, and 8 wk. Dietary calcium was determined with a validated food-frequency questionnaire. RESULTS: The net effect (+/-SE) of calcium supplementation on diastolic blood pressure was a reduction of 1.9 +/- 1.1 mm Hg (P = 0.04, one-tailed t test). Blood pressure reduction was greater in adolescents with lower intake of calcium from the diet (P = 0.003, one-tailed t test for interaction): -4.9 +/- 1.6, -2.3 +/- 1.6, and 1.4 +/- 1.8 mm Hg for change in the lower (0.024-0.067 g Ca/MJ), middle (0.069-0.091 g Ca/MJ), and upper (0.093-0.217 g Ca/MJ) tertiles, respectively. No main effect on systolic blood pressure was detected. CONCLUSION: These findings suggest that calcium supplementation may lower diastolic blood pressure in African American adolescents with low dietary intakes of calcium.

The risk of assaultive violence and alcohol availability in Los Angeles County.

OBJECTIVES: Although there is considerable evidence that alcohol consumption facilitates assaultive violence, the extent to which alcohol outlets in a community influence assaultive violence remains controversial. METHODS: To assess the geographic association between city-specific rates of assaultive violence and alcohol-outlet density, an ecologic analysis of the 74 larger cities in Los Angeles County was conducted for the 1990 reporting year. RESULTS: Sociodemographic factors alone accounted for 70% (R2 = .70) of the variance in the rate of assaultive violence in a multiple regression model. Adding the variable for alcohol-outlet density to the model yielded a significant positive slope. The magnitude of this relation indicates that in a typical Los Angeles County city (50,000 residents, 100 outlets, 570 offenses per year), one outlet was associated with 3.4 additional assaultive violence offenses in 1990. CONCLUSIONS: These findings indicate that higher levels of alcohol-outlet density are geographically associated with higher rates of assaultive violence. This association is independent of measured confounders, including city-level measures of unemployment, ethnic/racial makeup, income, age structure, city size, household size, and female-headed households.

Alcohol outlet density and motor vehicle crashes in Los Angeles County cities.

The extent to which the availability of alcohol encourages alcohol consumption resulting in alcohol-related problems remains controversial. In order to address this issue we used 1990 data from 72 cities within Los Angeles County to estimate the relation between densities of four types of alcohol outlets (restaurants, bars, liquor stores, mini-markets) and rates of two types of alcohol-related motor vehicle crashes reported by police (injury, property damage). After logarithmic transformation of variables, crash rates were regressed on outlet densities and possible demographic confounders. The demographic covariates accounted for 25% of the variance in injury crashes; adding the combined outlet density to the model yielded a significant elasticity estimate (beta +/- SE) (beta = 0.55 +/- 0.13). Separate models for types of outlets yielded significant elasticities for restaurants (beta = 0.22 +/- 0.07), liquor stores (beta = 0.46 +/- 0.17) and mini-markets (beta = 0.34 +/- 0.13), but not for bars (beta = 0.08 +/- 0.07). Alcohol-related crashes resulting in property damage also showed positive associations with outlet densities, but these associations were smaller and reached statistical significance for restaurants (beta = 0.19 +/- 0.11) and bars (beta = 0.21 +/- 0.10). Direction of influence cannot be inferred from these cross-sectional findings, but they do indicate that increased alcohol availability is geographically associated with increased alcohol-related motor vehicle crashes and that this association is independent of measured confounders.