Complexities in the assessment of alcohol intoxication, impairment and harms in naturalistic settings

The consumption of alcohol in public spaces such as the night-time economy (NTE) and music festivals has been linked to a host of harms experienced by patrons, such as aggression involvement and driving risk. Given the persistent and pervasive nature of risky alcohol use in the NTE and similar environments, much attention is being given to the assessment of its use and associated adverse outcomes in this context. The ability to comprehensively assess alcohol consumption, intoxication, impairment and associated harms is a key objective in public health domains. Research in this area can inform the target identification, design, implementation and efficacy of health interventions and health promotion initiatives, aimed at reducing harms among patrons. In order to develop appropriate interventions to be deployed in naturalistic drinking environments, it is important to first comprehensively understand how alcohol along with other substances are being used in these settings (i.e., consumption and intoxication), the demographic and behavioural profile of consumers, and how these are linked with the risk and experience of harms. However, there are innate and considerable methodological and logistical challenges associated with in-situ monitoring of alcohol use, impairment and related harm outcomes. The aim of this body of work was to identify some of these challenges, as well as investigate ways to improve upon current alcohol-related monitoring and risk identification in these naturalistic environments, focusing on four primary assessment techniques: (i) retrospective self-reports, (ii) event-level self-reports, (iii) objective biometric assessments (breath alcohol and transdermal alcohol techniques) and (iv) portable electronic cognitive-impairment assessments. Four studies were undertaken using one or a combination of the aforementioned assessment techniques: (1) a street-intercept retrospective self-report assessment of aggression involvement between NTE patrons (N=5,078) who reported alcohol use only versus NTE patrons who reported co-consuming alcohol and illicit substances, (2) a field-based methodological study (N=14) investigating the combined use of retrospective self-reports, prospective event-level self-reports and biometric assessments to measure alcohol consumption and intoxication over a multi-day event, and (3 & 4) a two-armed (field/laboratory and laboratory) study investigating the use of a portable cognitive assessment battery to assess the residual next-day cognitive effects of alcohol consumption (Phase 1 [field/laboratory] N=13, Phase 2 [laboratory] N=52). Study 1 found differences in retrospective aggression involvement between those who used alcohol only versus alcohol and other substances but highlighted a need for event-level measurements to further understand the relationship between substance use and harms. Thus, Study 2 investigated the simultaneous use of the aforementioned range of assessment techniques in a high-risk and prolonged drinking setting to better understand alcohol use in these environments, finding limitations with all assessments but merit in their combined use. Finally, Studies 3 and 4 indicated that while the deployment of portable cognitive assessments in real-world drinking settings is possible, the tasks themselves were not uniformly sensitive to detect alcohol-induced impairment at 0.08% breath alcohol concentration and that new tasks to assess impairment in these domains should be investigated. Overall, the combined findings of these studies offer a strengthened foundation on which to base and scale-up future alcohol-related assessments in naturalistic settings. However, a common theme throughout the work conducted is that alcohol-related assessments are still limited by the technology available, and complicated by the dynamic and complex nature of consumers and the environments in which they engage in these behaviours.