{'fraction_non_alphanumeric': 0.03166863672182821, 'fraction_numerical': 0.022015366430260048, 'mean_word_length': 5.123341375150784, 'pattern_counts': {'":': 0, '<': 4, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Alcohol sales in Canadian liquor outlets as a predictor of subsequent COVID‐19 infection rates: a time‐series analysis

Abstract Aims Government alcohol sales data were used to examine whether age 15+ per‐capita alcohol consumption (PCAC) (i) changed during COVID‐19 and (ii) predicted COVID‐19 infections 2–5 weeks later. Design Interrupted time‐series analyses were applied to panels of data before and after COVID‐19 restrictions were introduced in Canada. Setting and participants The populations, aged 15+, of the provinces of Ontario (ON), British Columbia (BC) and Nova Scotia (NS), Canada. Intervention Expansion of home delivery options and hours of trading for liquor stores while restrictions on travel, social and economic activities were imposed by governments during COVID‐19 from 17 March 2020 until 29 March 2021. Measurements Weekly estimates of (i) age 15+ PCAC using sales data supplied by provincial government alcohol distributors for liquor stores, bars and restaurants, (ii) stringency of public health measures assessed by the Public Health Agency of Canada (PHAC) and (iii) new COVID‐19 infections reported by PHAC. Findings PCAC increased by 7.10% (P = 0.013) during the pandemic versus previous years, with increased private liquor store sales partly offset by reduced bar/restaurant sales. Consumption was positively associated with stringency of public health measures. Weekly PCAC was positively associated with new COVID‐19 infections 2 weeks later (+6.34% for a one drink/week increase, P < 0.001). Lagged associations with COVID‐19 infections 2 or 3 weeks later were observed for PCAC from all sales channels, with larger effect sizes per standard drink/person/week increase for on‐premise outlets (+77.27% week 2, P = 0.009) than government liquor stores (+6.49%, week 2, P < 0.001) or private liquor stores (+7.13%, week 4, P < 0.001). Conclusions Alcohol consumption increased in three Canadian provinces during COVID‐19 to degrees corresponding to the extent of the strictness of measures imposed to prevent viral spread. Increased consumption of alcohol was associated with increased COVID‐19 infection rates 2 weeks later.


INTRODUCTION
Alcohol is the most widely used legally available recreational substance among Canadians [1]. The harms associated with alcohol use in Canada are high, with more than 18 000 deaths, 105 000 hospital admissions and more than 700 000 Emergency Room presentations estimated for the year 2017 [2]. By comparison, during the first 12 months of the pandemic, COVID-19 contributed to approximately 20 000 deaths and 40 000 hospital admissions [3].
In this paper we take advantage of access to detailed alcohol sales data from three Canadian government liquor distribution monopolies to explore how alcohol consumption levels changed during the public health restrictions introduced from 17 March 2020 following the World Health Organization's declaration of a global pandemic on 11 March 2020 [4]. Changes in alcohol consumption levels have implications for the extent of alcohol-related harms in a population and hence also the burden placed on health-care services, a special concern during a pandemic [5].
Alcohol consumption itself is a risk factor for the spread of COVID-19 infections by virtue of some high-risk contexts in which it is consumed (e.g. private functions, social gatherings, bars, restaurants) and by its demonstrated role in reducing social distancing [6].
We thus also explore in this paper whether relationships can be observed between levels of alcohol consumption in a population and later rates of COVID-19 infections. Given delays between both wholesale and retail alcohol purchases and actual alcohol consumption, on one hand, and the time to develop and have confirmed a COVID-19 infection (up to 2 weeks) [7] on the other, we investigated whether positive lagged associations would be found between alcohol consumption and rates of new infection between 2 and 5 weeks later.
Canadian and US jurisdictions quickly declared that off-premise alcohol sales were 'essential', together with groceries, pharmaceuticals and fuel. One justification provided by government spokespeople in several North American jurisdictions [8][9][10] was to protect healthcare resources from being overwhelmed by people going into alcohol withdrawal. Close analysis of the process of decision-making in California revealed the key role of the alcohol industry in promoting this narrative [8]. In fact, for Canada only approximately 5% of alcoholattributable hospital admissions involve alcohol withdrawal [5].
World-wide, analyses of sales and self-report survey data reveal a range of impacts on levels of alcohol consumption reflecting different policy measures and different economic conditions. Surveys in the United Kingdom, Ireland and Germany indicate increased consumption, but no changes or decreases in other European countries [11]. In Canada, respondents to a national survey were more likely to report increasing alcohol use during the first lockdowns imposed [12]. An analysis of beer sales in Australia suggested increased consumption during the first lockdown [13]; elsewhere, alcohol consumption was reduced by targeted restrictions on alcohol production and sale, e.g. Mexico [14], India [15] and South Africa [16].
We hypothesized that policies introduced in Canadian jurisdictions to ensure continued convenient access to off-premise alcohol (accounting for 80% of alcohol sales in Canada), with more accessible home delivery options for some manufacturers and retailers plus longer hours for some sales channels, would contribute to increased consumption overall during the lockdowns imposed during the COVID-19 pandemic. In British Columbia (BC) and Ontario (ON), liquor store hours increased from 98 to 112 hours per week and same-day home delivery options were introduced, directly from stores, restaurants and also through third-party delivery services such as UberEats [17,18]. Previously, home delivery was limited to some liquor stores and involved delays of several business days [19]. Nova Scotia (NS) expanded opportunities for online sales and home deliveries from breweries (with discounts for 12 packs). ON also reduced minimum prices for spirits with an alcohol content greater than 14.8% by volume [20].
Underlying mechanisms for increased consumption could also be psychological in terms of increased stress experienced by some people during lockdown [21], but also economic because of shifts towards purchasing cheaper alcohol from off-premise outlets. We hypothesized that increased stringency of all public health measures to combat COVID-19 had the common effects of restricting people to their homes while also increasing levels of stress, thus providing both more motivation and opportunity for increased alcohol consumption.
Finally, we predicted positive associations between levels of alcohol consumption and subsequent rates of new COVID-19 infections, with earlier associations for estimates made with retail sales from government stores than from wholesale sales to privately owned liquor stores, bars and restaurants. In summary, the research aimed to address the following questions relating to age 15+ PCAC, in total and by alternative sales channels: i. Did PCAC change during the first 12 months of the COVID-19 pandemic compared with previous years after controlling for seasonal effects, autocorrelation, moving averages, region and any pre-COVID trends?
ii. Was the degree of the change in PCAC associated with the stringency of overall public health measures?
iii. During the first 12 months of the pandemic, was weekly age 15-+ PCAC associated with changes in rates of new COVID-19 infections at lag weeks 2-5 after adjustment for region, pre-trend and season, autocorrelation, moving averages and stringency of public health measures?

Design
Interrupted time-series designs [22] were used to address each research question using weekly panels of data on per-capita alcohol consumption (PCAC), the stringency of applicable public health measures and rates of new COVID-19 infections for the provinces of BC, ON and NS. Auto-regressive integrated moving average (ARIMA) models [23,24] were used to analyse the panels of weekly time-series data for each of three provinces separately, with 154 pre-intervention There were limitations in the sales data provided by the LCBO for ON which were overcome by further estimation procedures. First, missing data for 1 week in May, 2020 were estimated taking midpoints of data points immediately before and afterwards. Secondly, the LCBO could not provide data on beer sales from private beer stores which account for almost two-thirds of beer sales in ON [30].
These missing data were estimated by comparing the LCBO data with comprehensive Statistics Canada reports of total off-premise beer sales and assuming that the difference for each time-period was made up by private beer store sales. The exact procedures used for these calculations are provided in Supporting information, Appendix A. As a sensitivity test, all analyses were conducted with and without ON data to determine if the pattern of results was markedly different.

COVID-19 infection data
The data on new COVID-19 infections were obtained from Canadian government sources [31]. Weekly rates of new infections per 100 000 people were calculated for each province between 17 March 2020 and 29 March 2021 to match the weekly age 15+ PCAC estimates.

Population data
Population data for each province were estimated and projected by Statistics Canada [28]. We used the spline method [32,33] to estimate weekly total population and population aged 15+ for the study period. The data were used to calculate weekly age 15+ PCAC and weekly rates of new infections per 100 000 population.

Measure of public health restrictions
The Public Health Agency's (PHAC) COVID-19 stringency index [34], adapted from the University of Oxford's stringency index [35], was Mixed linear regression models [25][26][27] were also used to analyse the pooled weekly PCAC drawn from all three provinces to address The following procedures were applied in all interrupted timeseries models reported here. First, the seasonal index method [36] was used to de-seasonalize the age 15+ PCAC data. The seasonal index was created by dividing each observation by the corresponding centred moving average [36,37], an appropriate method used in previous published studies [38,39]. Log-transformations were applied to correct for significantly skewed distributions and make the variance stationary for dependent variables [40], and also de-emphasize outliers [41]. The Durbin-Watson test [42] and the sample autocorrelation function plot (ACF) [43] were first used to test potential autoregressive and/or moving-average parameters for possible inclusion in models in order to control for their autoregressive and/or moving-average effects. We also used the augmented Dickey-Fuller (ADF) unit root test to confirm the stationarity of the de-seasonalized natural log-transformed time-series data in each province before implementing the ARIMA models. The sandwich estimation was used to estimate the 95% confidence interval (CI) to correct for heteroscedasticity [44]. The fully adjusted estimates from multi-level linear regression models controlled for the effects of trend change, seasonality (seasonal index method) and autoregressive moving-average within regions and over time and unobserved factors [45]. The Ljung-Box χ 2 test statistic was applied to the residuals series to confirm that they were uncorrelated, the values for these tests can be found in Table B1 in Supporting information, Appendix B. The t-test was used to test the significance of effects of interest. The likelihood ratio test was used to assess the model fit [46].
For the mixed models estimating lagged associations between PCAC and weekly infection rates, the natural log-transformed weekly infection rate was modelled and thus the coefficients of the exposure (i.e. weekly age 15+ per-capita standard drinks) can be interpreted as the percentage change in the infection rates for an additional standard drink per person 15+ per week after adjusting for the confounding effects of stringency index scores, linear trend and non-stationarity variance (by analyzing natural log-transformed rates). We also tested and specified the terms that represent autoregressive and/or moving average effects to adjust for these effects. Sensitivity tests were also performed for these analyses restricted to the provinces of British Columbia and Nova Scotia, given that private beer store sales were not available for Ontario.
We conducted all statistical analyses using SAS version 9.4 [47].
The SAS PROC ARIMA procedure was used to model time-series of weekly age 15+ per-capita alcohol consumption in each province and the SAS PROC MIXED procedure was used to model the pooled timeseries data of alcohol consumption and infection [26].

Descriptive statistics for key variables
Descriptive statistics (means, standard deviations and ranges) are summarized for the whole period of the study for each of the key variables in Supporting information, Appendix C (Table C1 and Figs C1 and C2). Estimates of weekly age 15+ PCAC followed similar patterns across the provinces, with slightly lower levels for ON and mostly higher for BC. Weekly rates of new COVID-19 infections were similar for ON and British BC but substantially lower in NS.

Associations between COVID-19 restrictions and PCAC
The public health restrictions introduced to limit the spread of COVID-19 followed a very similar pattern across the three provinces (Figs 1-3). The first phase saw the abrupt introduction of the strictest restrictions which were then gradually eased during the summer months, but then ramped up during the second wave of infections in late 2020.
Across the provinces, it was estimated that total age 15+ PCAC increased by 7.10% (8.335 versus 8.927, t-test P = 0.013) during the F I G U R E 1 Per capita standard drinks and stringency scores weekly in British Columbia during the study period COVID-19 pandemic versus the prior period after adjustment for seasonal, trend, autoregressive and moving average effects (Table 1).
There were significant positive associations between the strictness of public health measures (stringency score) and changes in age 15+ PCAC from off-premise outlets, but with larger effects for private compared with government-owned liquor stores (Table 2). For all provinces there were large negative associations between stringency score and a unit change (=1 standard drink per person age 15+ per week) in PCAC from on-premise outlets, i.e. bars and restaurants. The size of the overall association between changes in stringency scores and in PCAC ranged between a 0.77% increase in PCAC per standard drink per person per week in BC to a 1.45% increase for NS.

Lagged associations between PCAC and COVID-19 infection rates
Significant positive lagged associations were observed, mostly at week 2, between changes in PCAC and rates of new COVID-19 infections, as hypothesized (Table 3). A 6.34% increase in COVID-19 infection in population rates of new infections was estimated at lag week 2 (t-test P < 0.001) for one additional standard drink per person per week. As predicted, the lagged effect for private liquor stores was later (week 4) than for government liquor stores. A much larger percentage change was observed at lag week 2 (77.27%, F I G U R E 2 Per capita standard drinks and stringency scores weekly in Nova Scotia during the study period F I G U R E 3 Per capita standard drinks and stringency scores weekly in Ontario during the study period T A B L E 1 Percentage of changes in mean age 15+ per-capita alcohol sales (standard drinks/week) in total and by outlet type for BC, Ontario and Nova Scotia before and during the COVID-19 pandemic.    Tables E1 and E2 in Supporting information, Appendix E present sensitivity tests in which only observations for BC and NS were included. These show highly consistent but larger effect sizes for the same weekly lags as in Tables 3 below (and in Supporting information,   Table C2) in which data from ON were also included.

DISCUSSION
An increase in age 15+ PCAC was observed in the three provinces providing detailed alcohol sales data with an average effect of +7.10%, consistent with previous Canadian surveys (e.g. [12]). Consistent patterns were observed throughout the three provinces, with the greatest increases corresponding to the strict lockdown measures imposed during the first few months of the pandemic. The size of the overall annual increase in PCAC was smaller in BC (+2.01%), perhaps reflecting the absence of tourism during much of 2020, with BC normally having the highest rates of tourism [48]. There were substantial shifts in the patterns of alcohol sales from on-premise (bars and restaurants) to off-premise outlets, with the private off-premise sector benefiting the most. This probably reflects special measures made by governments to protect the private liquor store sector at a time when, immediately prior to COVID-19, pressures to privatize liquor distribution and sale had been mounting in Canada [49].
The hypothesis that increases in alcohol consumption would be positively related to the extent and strictness of all public health measures imposed was supported. It is important to note that the PHAC COVID-19 stringency score was based on a wide array of restrictions on the movement of people and imposition of social distancing requirements without any specific focus on liquor policies [6]. In practice, however, lockdowns frequently targeted on-premise liquor outlets because of such clear risk factors as groups of strangers meeting each other indoors as well as evidence that bars, restaurants and large social occasions are high-risk contexts for the spread of infection [50].
These associations were observed consistently throughout the three provinces.
Plausible mechanisms for the observed increases in alcohol consumption with evidence in the literature include stronger motivation to consume alcohol for some people to deal with stress during the pandemic [21], increased convenience of access by virtue of home delivery of alcohol (amplified by the emergence of third-party delivery services) plus extended hours of off-premise trading [5], and greater affordability of alcohol by virtue of the observed shift towards lowerpriced sales from off-premise rather than on-premise outlets.
Positive and significant associations between level of alcohol con-

CONCLUSIONS
We conclude that alcohol consumption increased in three Canadian provinces during COVID-19 to degrees corresponding to the extent of the strictness of measures imposed to prevent viral spread. We also conclude that increased consumption of alcohol was associated with increases in rates of new COVID-19 infections 2-4 weeks later.
As in many developed countries, Canadian policy on alcohol during COVID-19 combined a continued, convenient and affordable offpremise supply together with heavy restrictions for on-premise consumption. The net result was an overall increase in consumption which placed upward pressure on rates of new infections, and hence demand for health-care, despite the restrictions placed on bars and restaurants. It follows that policies to reduce population consumption of alcohol would probably have strengthened the public health response to containing the COVID-19 pandemic, i.e. by placing price and availability restrictions on off-premise as well as on-premise sales.
Such policies should also be considered during the recovery period rather than perpetuating the new relaxed alcohol policies. Examples of such policies include minimum unit pricing (MUP) for alcohol and increased alcohol taxes. MUP can help governments increase revenues while supporting both off-premise and on-premise outlets to make greater profits while selling less alcohol [5]. There are now many examples of Canadian governments making the relaxed alcohol policies introduced during the pandemic permanent (e.g. [17,18]).
(NSLC) and the Liquor Control Board of Ontario (LCBO) for access to detailed weekly alcohol sales data.