People predicted that the legislation would lead to them drinking more alcohol before they entered town or make little change to their drinking habits. Baseline data over the 2 years before the legislation (Study 3) demonstrated stable preloading rates and BrAC at entry to the NEDs. However, after the introduction of the legislation patrons entered the NEDs systematically later and increased their alcohol preloading. People were substantially more inebriated as they entered the NEDs after the legislative change, with approximately 50% fewer people not preloading after the new laws. Exit BrAC was less consistent but showed some evidence of an increase. Crime statistics and patrons’ self-reported experiences of violence did not change.

We conducted 3 studies–randomly breath-testing patrons for alcohol, as they entered and exited NEDs. Study 1 assessed patrons’ (n = 807) breath approximated blood alcohol concentration (BrAC) and predictions of how the legislation would change their drinking habits before the legislation was enacted. Study 2 assessed crime statistics and patrons’ BrAC levels and drug taking reports on an equivalent night, one year apart–before (n = 497) and after (n = 406) the new legislation. Study 3 was a test of the generalisation of Study 2 with two months of survey and BrAC data collected as people entered and exited the NEDs over two consecutive years before (n = 652 and n = 155) and one year after (n = 460) the new legislation. In Study 3 we also collected crime statistics and data on people leaving the entertainment district one year before (n = 502) and one year after (n = 514) the legislative change.

Restrictive practices on alcohol sales in entertainment districts have been introduced to reduce alcohol-related violence in youth. On 1 st July 2016, the Queensland State Government (Australia) imposed a 2-hour reduction in trading hours for alcohol sales in venues within specific night-time entertainment districts (NEDS; from 5am to 3am), a reduction in maximum trading hours for venues outside NEDs (with a maximum 2am closing time), the banning of ‘rapid intoxication drinks’ (e.g. shots) after 12am, and no new approvals for trading hours beyond 10pm for the sale of takeaway alcohol. No independent study has evaluated general levels of intoxication, crowd numbers, fear of violence, and illicit substance use as people enter and exit NEDS, both before and after the introduction of restrictive legislation. Further, no study has assessed the impact using matched times of the year in a controlled study and also assessed actual assault rates as recorded by the police.

Competing interests: The authors have declared that no competing interests exist. In particular, we have not received any funding during this research from local or state governments, political organisations, lobby groups, registered health charities that promote temperance, or companies involved in the supply or sale of alcohol.

Introduction

Binge drinking of alcohol (imbibing 5 or more drinks in one sitting [1]) is a global phenomenon that increases health risks in those who take part, whether that be in North America [2], the United Kingdom [3], Africa [4] or Asian and Caribbean countries [5]. These health risks include cancer, epilepsy, respiratory problems, liver failure and poor mental health. Binge drinking also disproportionately affects the developing brain of adolescents [6], and a disproportionate number of young people attend night-time entertainment districts (NEDs) where they engage in binge drinking, both before going out [7] and whilst out [3]. While a recent focus of research has quite rightly been aimed at discovering more about the trajectories that lead to alcohol abuse in adolescents [8], there has been a call for research which is more representative of low SES adolescents [9]. The current research focuses on a representative sample of youth in Australian NEDs, but has currency in all countries where youth congregate in similar venues.

In addition to medical health risks, ‘Alcohol fuelled violence’ is an oft-cited reason for temperance legislation and efforts to restrict opening hours of establishments selling alcohol. In Australia, this approach to violence reduction in NEDS has led to significant scientific [10, 11] and political [12] controversy. It is undisputed that there are more assaults and violent acts in Australian NEDs that stay open late and where alcohol is available, than in districts where alcohol is not available or where the clubs have earlier closing hours [13]. However, we are lacking data on whether assaults decrease as a result of reduced alcohol availability, or whether violence reduction is attributable to a decreased density of patrons in NEDs. We are also lacking convincing evidence that reductions in opening hours lead to a decrease in the general level of inebriation. Recent legislative changes in Queensland, Australia, provided a crucible in which we could test the effects of reduced drinking hours on inebriation and violence in NEDs.

In late 2015, the Queensland Government announced plans to introduce a “Tackling Alcohol-Fuelled Violence Amendment Bill”. Before this legislation, clubs were able to sell alcohol until 5am, with a 3am lockout. This lockout meant that after 3am people could not enter clubs, but those already inside could stay until 5am. The new legislation imposed a 2-hour reduction in trading hours for alcohol sales in venues within specific NEDs (from 5am to 3am), a reduction in maximum trading hours for venues outside NEDs (with a maximum 2am closing time), the banning of ‘rapid intoxication drinks’ (e.g. shots) after 12am, and no new approvals for trading hours beyond 10pm for the sale of takeaway alcohol. These aspects of the legislation came into effect on 1st July 2016. This change in policy allowed an independent research team with longitudinal data to test new hypotheses and clarify the results of older studies.

In their seminal study, Kypri, Jones, McElduff, & Barker (2011) [14] explored the impact of introducing an earlier (3am) closing time and a (1.30am) lockout in the central business district (CBD) of Newcastle (Australia) on numbers of assaults, compared with a control setting in a nearby location (Hamilton). While they found a decrease in the number of assaults in Newcastle compared with Hamilton following the introduction of reduced licensing hours, this could have been related to reductions in the number of patrons in the area, due to the lockout, and alcohol-related assaults being displaced to other places or settings. Any link between reductions in the number of assaults and the average level of inebriation in the NED is unclear, as it was not assessed. The current research programme built upon this previous research by assessing average inebriation levels and street numbers both before and after legislative changes that reduced alcohol availability in the NEDs of a large Australian city. The impact of these legislative changes on perceptions of violence in the NEDs and their attitude towards entering these districts were also assessed.

Devilly, Allen & Brown (2017) [7] recently reported on alcohol preloading behaviours in NEDs in Queensland, Australia. Preloading is the act of consuming alcohol or drugs before entering the NEDs and has become a growing phenomenon in westernised countries, particularly in the UK and USA [15]. Devilly et al found that 79% of respondents had preloaded with alcohol, and that 71% returned a Breath Alcohol Concentration (BrAC) greater than zero. Those who preloaded with alcohol before entry into the NEDs had an average BrAC of .071% pure ethanol (n = 1,952; .073% for males and .068% for females). The major reason given for preloading was ‘to socialise’, followed by ‘to save money’. Preloading behaviours were associated with increased reports of harm to oneself and others, either through the preloading itself, or through increased violence or riskier sexual practices. Preloading levels were only marginally related to the time of night that patrons entered the NEDs (r = .12) and the location of preloading (private residences or suburban bars) had no significant impact on inebriation levels. There is also data that patrons’ BrAC at the end of the night is highly correlated to their entry BrAC, even when taking gender, personality and demographics (i.e., age and body mass index) into account [16]. If the trend towards preloading were to intensify, and there were no incentives for patrons to come into the NED earlier to counteract this preloading, then the average intoxication level of the city may actually rise. Given the presence of a growing preloading trend [15], and that people’s motivations to drink satisfies inherent urges [17], we speculated that reducing the availability of alcohol later in the night may increase the perceived intrinsic value of alcohol and make it more desirable. Evidence for this cognitive bias (the ‘scarcity heuristic’) is found in Lynn’s (1989) [18] treatise, in which participants assumed a bottle of wine was more expensive when it was scarce. Scarcity increased both the perceived expensiveness and desirability of the wine, but only when the real cost of the wine was unknown. People were also more willing to buy the wine if they did not know how much it cost, or when it was a gift for a friend.

This ‘scarcity heuristic’ may arise from a restriction approach to alcohol in NEDs via two potentially countervailing effects: alcohol as an issue is brought into people’s consciousness and may be valued higher, which would prime people to increase their drinking; but perhaps also more expensive, which may decrease drinking. A likely solution would be for people to begin or increase their alcohol intake while it is cheap (i.e., before entering the NED) and subsequently moderate their drinking when it is expensive (i.e., once in the NED, and irrespective of whether they preloaded or not). This could occur under a context of determined drunkenness, where youth predominantly abstain from alcohol during the beginning of the week, but binge in the late week / weekend [19]. In fact, it may be that the scarcity heuristic even creates this ‘determined drunkenness’ in some new people. It could also be possible that ‘unit time’ to drink becomes what is more scarce and, in a preloading culture that punishes early entry to the NEDs with little to no socialisation, people start drinking or drink more during this preloading period. Indeed, there may be other models to guide expectations (e.g., the Availability Theory, particularly legal availability, as explained by Wagenaar and Perry, 1994 [20]), but we find the scarcity heuristic to be an explanation that is parsimonious with legislation that legally restricts alcohol sales in a preloading culture.

Following this heuristic, we would expect preloading to increase, raising the intoxication level of patrons entering NEDs. This would be particularly concerning, given the high unique variance (between 30% and 40% dependent upon gender) in the relationship between intoxication levels at NED entry and exit [16]. We would, therefore, expect that restricted trading hours may have the unintended effects of patrons being more inebriated at the beginning of their night out, and that at the end of the night they would either have the same or higher blood alcohol readings than before the legislation. This would particularly be the case if people titrate their drinking to reach a certain level of inebriation before stopping or slowing down. In consequence, we did not expect the changes in legislation to have their intended effects of reducing the number of assaults and the public’s fear of assault due to inebriation.

Since we had collected data before the legislation was proposed and continued collecting it after the legislation came into effect, we also had an opportunity to gauge people’s drinking intentions relating to the legislation, and see whether these intentions were reflected in behavioural changes after the legislation was implemented. We expected respondents to say that the legislative changes would not lead them to come to venues earlier (despite fewer hours being available for drinking), but that they instead would say that they would drink more before coming out and drink at a greater rate whilst out [18, 16].