Factors influencing risky single occasion drinking in Canada and policy implications

From a public health perspective, alcohol consumption is a challenging issue to address. Controversy existed in the research community whether low levels of alcohol consumption have protective effects, and if these effects outweigh known harms; however, there is a growing consensus in the literature that the positive effects of alcohol consumption have been overestimated in the past [1‐4]. Defining low-risk consumption has proved methodologically difficult, resulting in a variety of guidelines for low-risk alcohol intake across countries [5]. Likewise, alcohol misuse represents a wide spectrum of terms, from exceeding low-risk guidelines to alcohol dependence. A glossary of terms used in this article is outlined in Table 1.

Despite variation in how different organizations define and convey low-risk drinking, it is clear that the misuse of alcohol, including risky single occasion drinking (RSOD), is associated with a number of negative health, social, and economic consequences [6, 7]. Direct health implications associated with alcohol misuse include dependency, liver cirrhosis, organ damage, diabetes, cardiovascular disease, and various types of cancer [7, 8]. Furthermore, impaired judgement, impaired driving ([9]), injury, suicide, and risky sexual behaviour may be prompted by high levels of alcohol consumption, suggesting there may be broader health and social repercussions [7, 10]. In Canada, the most recent comprehensive economic analysis of alcohol-related costs was conducted in 2006 using data from 2002, and estimated that a total of CAD 14.6 billion was spent that year on direct and indirect costs [11, 12]. These costs are associated with healthcare, law enforcement, and productivity losses [7, 12]. Direct healthcare costs alone accounted for CAD 3.3 billion in spending in 2002 [7, 12]. More recently in 2013, the costs of Fetal Alcohol Spectrum Disorder (FASD) in Canada alone totalled approximately CAD 1.8 billion dollars [13] In contrast, the societal and healthcare costs of excessive alcohol use in the United States have been estimated at USD 223.5 billion and 24.5 billion, respectively [14]. Worldwide, alcohol abuse accounted for approximately 3.3 million deaths and 139 million disability-adjusted life years (DALYS) due to injury and morbidity [15]. Inhabitants of the North American region drank 8.4 l of pure alcohol per capita in 2010, 35% higher than the world average (6.2L) and second only to the European region (10.9 L). Among current alcohol drinkers in the Americas, the prevalence of heavy episodic drinking is 22%, again second only to Europe (22.9%). In the United States, the prevalence of monthly binge drinking defined in the article as 5+ drinks for men, 4+ for women in one occasion is approximately 17% [16].

A substantial proportion of these alcohol-related harms are associated with populations who exceeded low-risk alcohol guidelines, which is determined by quantity and/or frequency of alcohol use [7, 14, 17]. As the frequency of RSOD increases, the likelihood of negative health and social consequences increases [7, 17]. In addition, there is some evidence from the United States which indicates that moderate drinkers contributed to the majority of RSOD episodes ([18]).

Research shows that a number of economic, cultural, and historical factors contribute to individuals’ drinking practices [1, 19]. Data from the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC) and the National Survey on Drug Use and Health (NSDUH) demonstrated associations between early initiation of drinking (before the age of 21), age of 20–29 years, enrollment in college, being male and an increased engagement in RSOD, [1, 20]. However, it appears the gender gap is decreasing among younger cohorts [8]. In general, the factors that impact alcohol consumption have not been well explored within a Canadian context. Of particular interest may be how location of residence influences alcohol consumption in Canada, as provincial and territorial (P/T) jurisdiction over alcohol policy has created a patchwork of liquor regulations throughout the country [19, 21]. Studying provincial variations in alcohol consumption may provide insight into the impact of public policy, along with other cultural and socio-political differences, on RSOD. Furthermore, a deeper understanding of the risk factors that contribute to RSOD with respect to P/T may help guide relevant and informed alcohol related policies for each P/T.

Although experts agree that alcohol consumption can lead to negative health, social and economic consequences, defining low-risk intake has proved challenging for researchers and organizations [5, 12, 22]. Both volume and patterns of alcohol use can lead to separate risks, and studies have varied in their assessment of risk, with some focused on dose–response curves, while others focused on alcohol-attributable fractions [5]. Grams of pure alcohol per standard drink varies widely worldwide and portion sizes served often differ from the standard drink [5]. These debates added to the complexity for P/T governments and non-profit organisations to determine Canada’s Low Risk Alcohol Drinking Guidelines and communicate them to the public. In 2011, the National Alcohol Strategy Working Group (NASWG) recommended that, based on the available evidence, no more than two drinks should be consumed on most days for women (28 g of ethanol) and no more than three a day for men (42 g of ethanol) [23‐25]. Similarly, the guidelines recommend that over the duration of a week, women should consume less than 10 drinks and men less than 15 (140 and 210 g of pure alcohol, respectively) [23]. The CCSA defines risky drinking as “women having more than 3 drinks or for men more than 4 drinks on any single occasion once per month or more often” [23]. In contrast, the Canadian guidelines surrounding the definition of low-risk drinking are stricter compared to guidelines in the United States. For women, the National Institute on Abuse and Alcoholism (NIAA) [26] decrees that low-risk drinking consists of no more than 3 drinks per day and 7 per week (42 and 98 g of pure alcohol, respectively), whereas for men the guideline is 4 and 14 respectively (56 and 196 g of pure alcohol, respectively) [26]. European guidelines vary widely by country, and in response to this, recent practice principles from the Joint Action Reducing Alcohol Related Harm (RARHA) in Europe and the Center for Addiction and Mental Health (CAMH) have attempted to identify a standard definition of risk. They indicate that a level of alcohol intake of 10 g or less per day would result in an alcohol attributed death rate of below 1 in 100, and provide this as a suggested maximum for low risk drinking [27, 28]. This would equate with less than one standard drink per day in Canada, where one standard drink contains approximately 14 g of pure alcohol [24, 25].

The overall purpose of this study is to explore the past-year prevalence of RSOD in Canada and the factors associated with any RSOD and frequency of RSOD in Canada. Understanding the underlying factors contributing to RSOD in Canada will help guide the development of more effective policy interventions to curtail high-risk consumption. The two research questions developed were:

We defined infrequent RSOD as (past-year occurrence of drinking 5+ drinks (70+ grams alcohol) once a month or less) and frequent RSOD as (past-year occurrence of drinking 5+ drinks (70+ grams alcohol) more than once a month).

The Canadian Community Health Survey (CCHS) 2009–2010 annual component was used to conduct all the analyses in this paper ([29]). The sample size of this survey was 124,188. The response rate for the outcome variable of interest “How often in the past 12 months have you had 5 or more drinks on one occasion?” was 74.3%. Since logistic regression modeling uses listwise exclusion of missing values, the sample size of the regression models and descriptive statistics was 68,440. The sample was weighted using the survey weights provided by CCHS as instructed by Statistics Canada [30]. Descriptive statistics were conducted in SPSS Version 22.0 and regression modeling conducted using SAS 9.4 software. The alpha was set at 0.05.

This study is the first nation-wide study of factors, which are associated with the likelihood of individuals engaging in RSOD and frequency of engaging in RSOD in Canada. Multiple factors associated with RSOD identified in our models were consistent with the existing literature. Individuals who are male, unmarried or common-law, within the 18–24 year age range, and smoke were found to be more likely to engage in RSOD [1, 19, 31, 33] Other significant findings with regards to engaging in RSOD in the past year included: living in any province other than Ontario or British Columbia, being under 60 years of age, being widowed/separated/divorced, having a high income, reporting being stressed, being employed, and having a higher perceived health status. With regards to frequent RSOD, our findings were similar with notable differences identified for the P/T variable and the perceived life stress variable.

Socioeconomic status (SES), as a composite measure of an individual’s income, occupation, educational attainment, and social position in relation to others, has been generally linked to the risk of alcohol misuse including RSOD particularly among persons in the lowest SES strata [33‐35]. Breaking down this measure into its principal components: income, occupation, and educational attainment, we find conflicting results between all three variables across both statistical models.

Our findings relating to educational attainment are consistent with the literature in which individuals with higher educational attainment drink less at an occasion than those with lower levels of educational attainment [34, 35]. An alternative hypothesis for this relationship, aside from SES, is higher educational attainment has been linked to an increased uptake of healthy behaviors including reduced smoking, increased physical exercise, and more moderate alcohol consumption [36, 37]. This further supports the role of education as a major determinant of health.

Individuals in the highest income brackets surprisingly had much higher odds of engaging in any RSOD, including both infrequent and frequent RSOD, compared to those in the lowest income bracket controlling for all other factors including education. This finding differs from the literature, as studies examining RSOD indicate that individuals with lower incomes and SES engage in drinking that exceeds low risk guidelines more often than their counterparts with higher incomes [33, 35]. The centers for disease control and prevention [38] surveillance of binge drinking (defined equivalently with RSOD in our study as 5+ drinks on a single occasion) has demonstrated that the prevalence of RSOD is highest among those with a high household income, however the intensity and frequency of RSOD is highest among those with the lowest household income [38]. Studies have also found that individuals with higher incomes tend to drink more often, however whether these individuals reach the threshold of RSOD is up for debate [34]. In addition, research on the relationship between alcohol use and wage earnings has demonstrated that individuals who drink earn higher wages than non-drinkers [39] however individuals who drink excessively earn less, suggesting an inverse u-shape relationship between alcohol use and wage earnings and income [40].

Currently there is limited Canadian literature on the relationship between employment factors and alcohol intake [41]. In this study, after controlling for all other independent variables, we found that being employed in the last week increased the odds of engaging in both infrequent and frequent RSOD compared to those unemployed. These findings, while inconsistent with the SES theory, are consistent with the findings of Marchand et al. [41] which found that hours worked per week were associated with increased frequency of RSOD. Moreover, Brown et al. [42] found unemployed individuals to be less likely to engage in heavy alcohol consumption, which the authors theorized could be due to a lack of funds or underreporting by this population group. This association between employment and RSOD may be further linked by type of employment and occupational status, unavailable in this dataset, and highlights an area for further exploration within the Canadian context.

As for the link between self-perceived health status and RSOD, we found in both models that as self-perceived health status is associated with an increase in the odds of infrequent and frequent RSOD. These findings differ from the existing literature outlining that increased alcohol use is correlated with lower self-perceived health scores [43]. However, studies have demonstrated that alcohol consumption decision making may be influenced by underlying health concerns [44]. It is possible that there may be a clinically-induced relationship between illness, pharmaceutical interventions, and the consumption of alcohol. This relationship was not explored in this study.

Interestingly, perceived stress increased the odds of infrequent RSOD but not frequent RSOD. Alcohol, as a depressant, is generally viewed as a coping mechanism for life stress and higher levels of stress in the form of job insecurity is linked to high-risk alcohol consumption [41]. However, one would expect that this relationship would extend into frequent RSOD.

We found that smokers, at any level, are much more likely to engage in RSOD and frequent RSOD compared to non-smokers. This relationship was much stronger at predicting frequent RSOD, suggesting a strong link between alcohol use and smoking. This finding is consistent with the literature linking smoking with alcohol abuse and other illicit drug use ([45, 46]).

As expected, marriage is associated with a protective effect on the risk of RSOD. However, persons living in common-law were more likely to engage in any RSOD and frequent RSOD than married individuals. This is interesting because common-law couples have enjoyed similar tax benefits and legal status in Canada as married couples due to high profile court cases Egan v. Canada [47] and M. v. H. [48]. Research on the differences between common-law and married couples has demonstrated that common-law couples are more likely to separate than married couples [49], are more likely to experience relationship strain [50], and enjoy fewer economic benefits [51]. The higher levels of instability in common-law relationships and households may contribute to the increased odds of RSOD and frequent RSOD.

Finally, province of residence was associated with the likelihood of engaging in RSOD. Persons living in Atlantic Canada or in one of the three Territories were more likely to engage in infrequent and frequent RSOD compared to Ontario. In the literature, comparative data pertaining to RSOD by province was not available; however, statistics show higher rates of overall consumption in the Territories, British Columbia, Alberta, and Newfoundland and Labrador [19]. This P/T variation is likely due to a myriad of factors including: alcohol policies and taxation, cultural norms, historical factors, and the social environment [19, 52, 53].

Although the legal age for purchase of alcohol in Canadian P/T is 19 years except in Alberta, Manitoba and Quebec, the regulatory system of alcohol sale is complicated. The retail liquor sale is wholly private (AB), exclusively controlled by Government (PEI, NB, NWT) or mixed controlled by both private and public systems (NS, QC, ON, SK, MB, BC, YT) [54]. The system is further complicated by permitting delisted products to be sold at significantly less than minimum price (SK), establishing special outlets for selling at discounted prices or allowing private liquor stores selling less than minimum price (BC) [55].

As for an association between P/T alcohol policies and RSOD, our findings did not uncover a link between the two variables. For instance, residents of Saskatchewan and Alberta had similar results with relation to RSOD; however these provinces employ very different alcohol policies. Saskatchewan has a mixed government and private sales structure whereby minimum prices are set in government stores and prices are indexed to inflation; whereas Alberta employs a free-market with regard to alcohol sales with privatization, no minimum prices, and no indexing to inflation [23]. Although factors such as price controls and tax policy have been shown to reduce regular alcohol consumption and heavy drinking [32], the effects of these forms of policy were not evident in our study. Therefore more direct research on this topic is needed to determine the best methods for provincial governments to control RSOD.

Our findings extend the existing literature by focusing on the Canadian population, and demonstrate that age, sex, education, income, employment, marital status, smoking status, life stress, self-perceived health, and province of residence are associated with RSOD and the frequency of RSOD.

This paper examined RSOD and frequent RSOD within the Canadian population. It was found that engaging in RSOD was significantly influenced by a myriad of demographic, socioeconomic, and health status variables. More research into the factors which we found to influence RSOD is needed to determine ways to mediate RSOD at all levels within the Canadian population as it is associated with negative health and social implications [7, 8].

It is important for policy-makers and researchers to start to consider the impact of people who participate in both infrequent and frequent RSOD, as those who engage in frequent RSOD are more likely to have serious negative health consequences however those who engage in infrequent RSOD remain at risk and represent a larger proportion of the Canadian population. As with Geoffrey Rose’s prevention paradox [57], targeting higher risk populations (frequent risky single occasion drinkers) for prevention is effective but not as effective as a mass prevention strategy in order to shift the whole population’s distribution of RSOD downwards.

Attempts at reducing RSOD through traditional health promotion efforts such as educational and media campaigns have proven largely ineffective [58], however studies have shown that changing perceptions about RSOD and cultural norms can be effective [59]. In addition research has shown that alcohol consumption is price-sensitive [60] and heavier drinkers may be more sensitive to price changes [61]. Therefore effective prevention strategies should include aspects of changing perceptions, especially among youth and young adults, about RSOD and cultural norms in conjunction with changes to provincial alcohol policies and taxation.

Additionally, our finding associating smoking with RSOD specifically suggests an opportunity to combine public health prevention strategies for both substances. Policies surrounding “cultural norms” with regards to RSOD, along with effective alcohol price controls are likely to reduce the prevalence and frequency of RSOD in Canada.