Christopher Morrison

Relating off-premises alcohol outlet density to intentional and unintentional injuries.

AIMS This study investigated the hypotheses that (i) intentional and unintentional injuries occur more frequently in areas with greater density of off-premises alcohol outlets; and (ii) larger and chain outlets selling cheaper alcohol contribute more substantially to injury risk than smaller and independent outlets. DESIGN Ecological cross-sectional. SETTING From the 256 Statistical Area level 2 (SA2) census units in Melbourne, Australia, we selected a random sample of 62 units. There were 2119 Statistical Area level 1 (SA1) units nested within the selected SA2 units. PARTICIPANTS The selected units contained 295 off-premises outlets. MEASUREMENTS Two independent observers conducted premises assessments in all off-premises outlets, assessing the volume of alcohol available for sale (paces of shelf space), price (least wine price) and other operating characteristics (chain versus independent, drive-through). Outlet counts, assessed outlet characteristics and other area characteristics (population density, median age, median income, retail zoning) were aggregated within SA1 units. Dependent variables were counts of ambulance attended intentional injuries (assaults, stabbings, shootings) and unintentional injuries (falls, crush injuries and object strikes). FINDINGS In univariable analyses, chain outlets were larger (r = 0.383; P < 0.001) and sold cheaper alcohol (r = -0.484; P < 0.001) compared with independent outlets. In Bayesian spatial Poisson models, off-premises outlet density was positively related to both intentional [incidence rate ratio (IRR) = 1.38; 95% credible interval (CI) = 1.19, 1.60] and unintentional injuries (IRR = 1.18; 95% CI = 1.06, 1.30). After disaggregation by outlet characteristics, chain outlet density was also related to both intentional (IRR = 1.35; 95% CI = 1.11, 1.64) and unintentional injuries (IRR = 1.20; 95% CI = 1.08, 1.38). CONCLUSIONS Greater off-premises outlet density is related to greater incidence of traumatic injury, and chain outlets appear to contribute most substantially to traumatic injury risk.

Quantifying Disparities in Urban Firearm Violence by Race and Place in Philadelphia, Pennsylvania: A Cartographic Study

Objectives To describe variability in the burden of firearm violence by race, income, and place in an urban context. Methods We used Philadelphia Police Department data from 2013 to 2014 to calculate firearm assault rates within census block groups for both victim residence and event locations, stratifying by race and block group income. We used cartographic modeling to determine variations in incidence of firearm assault by race, neighborhood income, and place. Results The overall rate of firearm assault was 5.0 times higher (95% confidence interval [CI] = 4.5, 5.6) for Black people compared with White people. Firearm assault rates were higher among Black people across all victim residence incomes. Relative risk of firearm assault reached 15.8 times higher (95% CI = 10.7, 23.2) for Black residents in the highest-income block groups when compared with high-income White individuals. Firearm assault events tended to occur in low-income areas and were concentrated in several “hot spot” locations with high proportions of Black residents. Conclusions Profound disparity in exposure to firearm violence by race and place exists in Philadelphia. Black people were substantially more likely than White people to sustain firearm assault, regardless of neighborhood income.

Commentary on Gmel et al. (2015): Are alcohol outlet densities strongly associated with alcohol‐related outcomes? A critical review of recent evidence

We read with interest the recent systematic review by Gmel, Holmes and Studer [1], summarising the January 2009 to October 2014 literature regarding ecological relationships between alcohol outlet density and alcohol-related outcomes. Given the recent proliferation of studies in this area, an updated synthesis is timely and most welcome. However, we have a number of concerns about the methods and theoretical approach the authors used. In particular, we believe the review does not take into consideration the quality of the included studies, and that the authors overstate the effects of ecological bias and the modifiable areal unit problem. Moreover, by limiting the review to so narrow a time frame, they missed an opportunity to assess recent studies within the context of a literature that dates back almost half a century [2,3]. In our opinion, the main conclusion, that ‘it makes little sense to continue aggregate-level studies in which heterogeneous outlet types are aggregated’, does not do justice to the state of the science.

Spatial relationships between alcohol-related road crashes and retail alcohol availability

BACKGROUND This study examines spatial relationships between alcohol outlet density and the incidence of alcohol-related crashes. The few prior studies conducted in this area used relatively large spatial units; here we use highly resolved units from Melbourne, Australia (Statistical Area level 1 [SA1] units: mean land area=0.5 km(2); SD=2.2 km(2)), in order to assess different micro-scale spatial relationships for on- and off-premise outlets. METHODS Bayesian conditional autoregressive Poisson models were used to assess cross-sectional relationships of three-year counts of alcohol-related crashes (2010-2012) attended by Ambulance Victoria paramedics to densities of bars, restaurants, and off-premise outlets controlling for other land use, demographic and roadway characteristics. RESULTS Alcohol-related crashes were not related to bar density within local SA1 units, but were positively related to bar density in adjacent SA1 units. Alcohol-related crashes were negatively related to off-premise outlet density in local SA1 units. CONCLUSIONS Examined in one metropolitan area using small spatial units, bar density is related to greater crash risk in surrounding areas. Observed negative relationships for off-premise outlets may be because the origins and destinations of alcohol-affected journeys are in distal locations relative to outlets.

Commentary on Gmel etal. (2015)

We read with interest the recent systematic review by Gmel, Holmes and Studer [1], summarising the January 2009 to October 2014 literature regarding ecological relationships between alcohol outlet density and alcohol-related outcomes. Given the recent proliferation of studies in this area, an updated synthesis is timely and most welcome. However, we have a number of concerns about the methods and theoretical approach the authors used. In particular, we believe the review does not take into consideration the quality of the included studies, and that the authors overstate the effects of ecological bias and the modifiable areal unit problem. Moreover, by limiting the review to so narrow a time frame, they missed an opportunity to assess recent studies within the context of a literature that dates back almost half a century [2,3]. In our opinion, the main conclusion, that ‘it makes little sense to continue aggregate-level studies in which heterogeneous outlet types are aggregated’, does not do justice to the state of the science.

Social disadvantage and exposure to lower priced alcohol in off-premise outlets

INTRODUCTION AND AIMS Greater concentrations of off-premise alcohol outlets are found in areas of social disadvantage, exposing disadvantaged populations to excess risk for problems such as assault, child abuse and intimate partner violence. This study examines whether the outlets to which they are exposed also sell cheaper alcohol, potentially further contributing to income-related health disparities. DESIGN AND METHODS We conducted unobtrusive observations in 295 off-premise outlets in Melbourne, Australia, randomly selected using a spatial sample frame. In semi-logged linear regression models, we related the minimum purchase price for a 750 mL bottle of wine to a national index of socioeconomic advantage for the census areas in which the outlets were located. Other independent variables characterised outlet features (e.g. volume, chain management) and conditions of the local alcohol market (adjacent outlet characteristics, neighbourhood characteristics). RESULTS A one decile increase in socioeconomic advantage was related to a 1.3% increase in logged price. Larger outlets, chains, outlets adjacent to chains, outlets in greater proximity to the nearest neighbouring outlet and those located in areas with more students also had cheaper alcohol. DISCUSSION AND CONCLUSIONS Not only are disadvantaged populations exposed to more outlets, the outlets to which they are exposed sell cheaper alcohol. This finding appears to be consistent with the spatial dynamics of typical retail markets.

Ridesharing and Motor Vehicle Crashes in 4 US Cities: An Interrupted Time-Series Analysis

Uber, the worlds largest ridesharing company, has reportedly provided over 2 billion journeys globally since operations began in 2010; however, the impact on motor vehicle crashes is unclear. Theoretically, ridesharing could reduce alcohol-involved crashes in locations where other modes of transportation are less attractive than driving ones own vehicle while under the influence of alcohol. We conducted interrupted time-series analyses using weekly counts of injury crashes and the proportion that were alcohol-involved in 4 US cities (Las Vegas, Nevada; Reno, Nevada; Portland, Oregon; and San Antonio, Texas). We considered that a resumption of Uber operations after a temporary break would produce a more substantial change in ridership than an initial launch, so we selected cities where Uber launched, ceased, and then resumed operations (2013-2016). We hypothesized that Ubers resumption would be associated with fewer alcohol-involved crashes. Results partially supported this hypothesis. For example, in Portland, Ubers resumption was associated with a 61.8% reduction (95% confidence interval: 38.7, 86.4) in the alcohol-involved crash rate (an absolute decrease of 3.1 (95% confidence interval: 1.7, 4.4) alcohol-involved crashes per week); however, there was no concomitant change in all injury crashes. Relationships between ridesharing and motor vehicle crashes differ between cities over time and may depend on specific local characteristics.

The reliability of naturalistic observations of social, physical and economic environments of bars

Abstract Drinking in bars contributes to numerous public health problems, including violence and motor vehicle crashes. In order to formulate effective preventive interventions, it is essential to identify which specific features of bar environments are related to increased risks. Unobtrusive ethnographic observations are one approach that has been used to characterize these features; however, no studies have assessed reliability in a representative sample of bars. We performed brief scouting assessments in all 165 bars in six purposively selected California cities, followed by unobtrusive observations from a subsequent representative sample of 97 bars which were located in low- and high-bar density areas of the cities. Inter-rater reliability between two independent observers assessed individual item reliability, and principal components analyses assessed the reliability of a series of scales describing the physical, social, and economic characteristics of the bars. For the scouting assessment, items exhibited at least moderate reliability (κ or r ≥ 0.40). For the unobtrusive observations, items assessing physical and economic environments (e.g. pool table present, κ = 0.90; index beer cost, r = 0.82) had moderate to outstanding reliability (κ or r > 0.80). Items describing the social environment generally had poorer reliability, though group aspects (e.g. patron count, r = 0.78; patron circulation, r = 0.64) had better reliability than individual behaviors (e.g. derogatory speech, κ = 0.12). Scales constructed from specific sets of items exhibited modest reliability. The individual metrics and principal components we present will enable future studies seeking to disaggregate relationships between bar characteristics and public health problems.

A Critical Assessment of Bias in Survey Studies Using Location-Based Sampling to Recruit Patrons in Bars

Location-based sampling is a method to obtain samples of people within ecological contexts relevant to specific public health outcomes. Random selection increases generalizability; however, in some circumstances (such as surveying bar patrons), recruitment conditions increase risks of sample bias. We attempted to recruit representative samples of bars and patrons in six California cities, but low response rates precluded meaningful analysis. A systematic review of 24 similar studies revealed that none addressed the key shortcomings of our study. We recommend steps to improve studies that use location-based sampling: (i) purposively sample places of interest, (ii) use recruitment strategies appropriate to the environment, and (iii) provide full information on response rates at all levels of sampling.

Are barroom and neighborhood characteristics independently related to local-area assaults?

BACKGROUND Two separate but complementary literatures examine bar-related violence: one has focused on barroom features, and the other has focused on features of neighborhoods near bars. This study unifies these 2 perspectives using a microenvironmental approach. METHODS In a purposive sample of 65 bars in 4 California cities, we used premise assessments to characterize the physical, social, and economic environments of barrooms (e.g., patron count, average pace of drinking, and restaurant service); and a combination of systematic social observation, census, and alcohol license data to characterize the neighborhoods in which they were located (e.g., physical disorder, alcohol outlet density, and median household income). Hierarchical Poisson models then assessed relationships between these features and counts of police-reported assaults within buffer areas around bars. RESULTS Aspects of both barroom environments (more patrons, more dancing, and louder music) and neighborhood environments (greater bar density, greater physical disorder, lower population density, and lower income) were independently related to increased incidence of assaults. CONCLUSIONS Preventive intervention to reduce bar-area violence may be directed at both bar environments (e.g., limiting the number of patrons) and neighborhood environments (e.g., limiting outlet density).