Kate Vallance

The relationship between minimum alcohol prices, outlet densities and alcohol‐attributable deaths in British Columbia, 2002–09

AIM To investigate relationships between periodic increases in minimum alcohol prices, changing densities of liquor stores and alcohol-attributable (AA) deaths in British Columbia, Canada. DESIGN Cross-section (16 geographic areas) versus time-series (32 annual quarters) panel analyses were conducted with AA deaths as dependent variables and price, outlet densities and socio-demographic characteristics as independent variables. SETTING AND PARTICIPANTS Populations of 16 Health Service Delivery Areas in British Columbia, Canada. MEASUREMENTS Age-sex-standardized rates of acute, chronic and wholly AA mortality; population densities of restaurants, bars, government and private liquor stores; minimum prices of alcohol in dollars per standard drink. FINDINGS A 10% increase in average minimum price for all alcoholic beverages was associated with a 31.72% [95% confidence interval (CI): ± 25.73%, P < 0.05] reduction in wholly AA deaths. Significantly negative lagged associations were also detected up to 12 months after minimum price increases for wholly but not for acute or chronic AA deaths. Significant reductions in chronic and total AA deaths were detected between 2 and 3 years after minimum price increases. Significant but inconsistent lagged associations were detected for acute AA deaths. A 10% increase in private liquor stores was associated with a 2.45% (95% CI: ± 2.39%, P < 0.05), 2.36% (95% CI: ± 1.57%, P < 0.05) and 1.99% (95% CI: ± 1.76%, P < 0.05) increase in acute, chronic and total AA mortality rates. CONCLUSION Increases in the minimum price of alcohol in British Columbia, Canada, between 2002 and 2009 were associated with immediate and delayed decreases in alcohol-attributable mortality. By contrast, increases in the density of private liquor stores were associated with increases in alcohol-attributable mortality.

Minimum Alcohol Prices and Outlet Densities in British Columbia, Canada: Estimated Impacts on Alcohol-Attributable Hospital Admissions

OBJECTIVES We investigated whether periodic increases in minimum alcohol prices were associated with reduced alcohol-attributable hospital admissions in British Columbia. METHODS The longitudinal panel study (2002-2009) incorporated minimum alcohol prices, density of alcohol outlets, and age- and gender-standardized rates of acute, chronic, and 100% alcohol-attributable admissions. We applied mixed-method regression models to data from 89 geographic areas of British Columbia across 32 time periods, adjusting for spatial and temporal autocorrelation, moving average effects, season, and a range of economic and social variables. RESULTS A 10% increase in the average minimum price of all alcoholic beverages was associated with an 8.95% decrease in acute alcohol-attributable admissions and a 9.22% reduction in chronic alcohol-attributable admissions 2 years later. A Can

Impact on alcohol‐related mortality of a rapid rise in the density of private liquor outlets in British Columbia: a local area multi‐level analysis

0.10 increase in average minimum price would prevent 166 acute admissions in the 1st year and 275 chronic admissions 2 years later. We also estimated significant, though smaller, adverse impacts of increased private liquor store density on hospital admission rates for all types of alcohol-attributable admissions. CONCLUSIONS Significant health benefits were observed when minimum alcohol prices in British Columbia were increased. By contrast, adverse health outcomes were associated with an expansion of private liquor stores.

A 'standard joint'? the role of quantity in predicting cannabis-related problems

AIMS To study relationships between rates of alcohol-related deaths and (i) the density of liquor outlets and (ii) the proportion of liquor stores owned privately in British Columbia (BC) during a period of rapid increase in private stores. DESIGN Multi-level regression analyses assessed the relationship between population rates of private liquor stores and alcohol-related mortality after adjusting for potential confounding. SETTING The 89 local health areas of BC, Canada across a 6-year period from 2003 to 2008, for a longitudinal sample with n = 534. MEASUREMENTS Population rates of liquor store density, alcohol-related death and socio-economic variables obtained from government sources. FINDINGS The total number of liquor stores per 1000 residents was associated significantly and positively with population rates of alcohol-related death (P < 0.01). A conservative estimate is that rates of alcohol-related death increased by 3.25% for each 20% increase in private store density. The percentage of liquor stores in private ownership was also associated independently with local rates of alcohol-related death after controlling for overall liquor store density (P < 0.05). Alternative models confirmed significant relationships between changes in private store density and mortality over time. CONCLUSIONS The rapidly rising densities of private liquor stores in British Columbia from 2003 to 2008 was associated with a significant local-area increase in rates of alcohol-related death.

Sexual identity and drug use harm among high-risk, active substance users

The ‘standard drink’ concept is widely used as a standardized measure of alcohol consumption. There is no equivalent measure of cannabis consumption, perhaps due to challenges such as varied joint size, tetrahydrocannabinol content, and means of delivery. This study introduces a new measure of cannabis quantity and examines whether it predicts cannabis-related social problems with and without controlling for frequency of use. Cannabis-related problems, measured by the Alcohol, Smoking and Substance Involvement Screening Test (ASSIST), were predicted from cannabis use frequency (days in past month) and quantity (one joint = 0.5 g, five bong or pipe hits, 10 puffs), controlling for age and gender. The sample consisted of 665 participants aged 15–67 (mean = 28.2, SD = 11.8) from the British Columbia Alcohol and Other Drug Monitoring Project, High Risk Group Surveys, 2008 to 2009. Cannabis use frequency and quantity were positively associated with cannabis-related problems. Individuals who consumed cannabis daily and consumed more than one joint per day were at the greatest risk of problems. Controlling for frequency, the effect of quantity remained significant for failure to do what is expected due to cannabis use. This study suggests that quantity, above and beyond frequency, is an important predictor of cannabis problems. We discuss the potential usefulness and validity of this new measure in harm reduction.

Evaluating recall bias in a case-crossover design estimating risk of injury related to alcohol: Data from six countries

Research shows that sexual minorities are at greater risk for illicit substance use and related harm than their heterosexual counterparts. This study examines a group of active drug users to assess whether sexual identity predicts increased risk of substance use and harm from ecstasy, ketamine, alcohol, marijuana, cocaine and crack. Structured interviews were conducted with participants aged 15 years and older in Vancouver and Victoria, BC, Canada, during 2008–2012. Harm was measured with the World Health Organizations AUDIT and ASSIST tools. Regression analysis controlling for age, gender, education, housing and employment revealed lesbian, gay or bisexual individuals were significantly more likely to have used ecstasy, ketamine and alcohol in the past 30 days compared to heterosexual participants. Inadequate housing increased the likelihood of crack use among both lesbian, gay and bisexuals and heterosexuals, but with considerably higher odds for the lesbian, gay and bisexual group. Lesbian, gay and bisexual participants reported less alcohol harm but greater ecstasy and ketamine harm, the latter two categorised by the ASSIST as amphetamine and hallucinogen harms. Results suggest encouraging harm reduction among sexual minority, high-risk drug users, emphasising ecstasy and ketamine. The impact of stable housing on drug use should also be considered.

Explaining the Health Gap Experienced by Girls and Women in Canada: A Social Determinants of Health Perspective

INTRODUCTION AND AIMS Prior work suggests that recall bias may be a threat to the validity of relative risk estimation of injury due to alcohol consumption, when the case-crossover method is used based on drinking during the same six hours period the week prior to injury as the control period. This work explores the issue of alcohol recall bias used in the case-crossover design. DESIGN AND METHODS Data were collected on injury patients from emergency room studies across six countries (Dominican Republic, Guatemala, Guyana, Nicaragua, Panama and Canada), conducted in 2009-2011, each with n ≈ 500 except Canada (n = 249). Recall bias was evaluated comparing drinking during two control periods: the same six hours period the day before versus the week before injury. RESULTS A greater likelihood of drinking yesterday compared with last week was seen using data from the Dominican Republic, while lower likelihood of drinking yesterday was found in Guatemala and Nicaragua. When the data from all six countries were combined, no differential drinking between the two control periods was observed. DISCUSSION AND CONCLUSIONS These findings are in contrast to earlier studies showing a downward recall bias of drinking, and suggest that it may be premature to dismiss the last week case-crossover method as a valid approach to estimating risk of injury related to drinking. However, the heterogeneity across countries suggests that there may be some unexplained measurement error beyond random sampling error.

An examination of injection drug use trends in Victoria and Vancouver, BC after the closure of Victoria's only fixed-site needle and syringe programme.

In the last few decades there has been a resurgence of interest in the social causes of health inequities among and between individuals and populations. This ‘social determinants’ perspective focuses on the myriad demographic and societal factors that shape health and well-being. Heeding calls for the mainstreaming of two very specific health determinants - sex and gender - we incorporate both into our analysis of the health gap experienced by girls and women in Canada. However, we take an intersectional approach in that we argue that a comprehensive picture of health inequities must, in addition to considering sex and gender, include a context sensitive analysis of all the major dimensions of social stratification. In the case of the current worldwide economic downturn, and the uniquely diverse Canadian population spread over a vast territory, this means thinking carefully about how socioeconomic status, race, ethnicity, immigrant status, employment status and geography uniquely shape the health of all Canadians, but especially girls and women. We argue that while a social determinants of health perspective is important in its own right, it needs to be understood against the backdrop of broader structural processes that shape Canadian health policy and practice. By doing so we can observe how the social safety net of all Canadians has been eroding, especially for those occupying vulnerable social locations.

Risk of injury from alcohol, marijuana and other drug use among emergency department patients

BACKGROUND Needle and syringe programmes (NSPs) have been established as effective harm reduction initiatives to reduce injection drug use (IDU)-related risk behaviours, including sharing needles. On May 31, 2008, Victoria, BCs only fixed site NSP was shut down due to community and political pressure. This study examines and compares IDU trends in Victoria with those in Vancouver, BC, a city which has not experienced any similar disruption of IDU-related public health measures. METHODS Quantitative and qualitative data were collected by interviewer-administered questionnaires conducted with injection drug users (n=579) in Victoria and Vancouver between late 2007 and late 2010. RESULTS Needle sharing increased in Victoria from under 10% in early 2008 to 20% in late 2010, whilst rates remained relatively low in Vancouver. Participants in Victoria were significantly more likely to share needles than participants in Vancouver. Qualitative data collected in Victoria highlight the difficulty participants have experienced obtaining clean needles since the NSP closed. Recent injection of crack cocaine was independently associated with needle sharing. CONCLUSIONS The closure of Victorias fixed site NSP has likely resulted in increased engagement in high-risk behaviours, specifically needle sharing. Our findings highlight the contribution of NSPs as an essential public health measure.

Concordance of self-reported drug use and saliva drug tests in a sample of emergency department patients

BACKGROUND Alcohol is known to be associated with injury, but little is known of combined use of alcohol and other drugs on injury; especially important for marijuana, given increasing legalization of use in the U.S. and Canada. METHODS Probability samples of patients 18 and older were interviewed in the emergency department at two sites in Vancouver and one in Victoria, BC (n=1191 injured and 1613 non-injured patients). Case-control and case-crossover analyses were used to analyze risk of injury, based on self-reported alcohol and drug use (marijuana, stimulants, depressants) prior to injury. RESULTS Risk of injury was significantly elevated (p<0.001) for alcohol use alone in both case-control (OR=2.72) and case-crossover analyses (OR=2.80) but not for any of the three drug classes. The interaction of alcohol with each class of drug was tested, and marginally significant only for marijuana in case-control analysis (OR=4.42; p=0.088). The interaction of alcohol and two or more drugs was also significant in case-control analysis (OR=03; p=0.035). The volume of alcohol consumed prior to injury was greater for those also using drugs during this time and positively associated with the number of drugs reported. CONCLUSION Given the potential issues involved with both case-control and case-crossover study designs, the inconsistent findings suggest caution in reaching any definite conclusion regarding whether there is extra risk related to combined use of alcohol and marijuana, and is an important area for future research.