ABSTRACT: High-Intensity Drinking over the Life Course: Identifying high-risk subgroups through event-based and population-based approaches Binge or heavy episodic drinking (HED) of ≥4/ ≥5 drinks for women/men in a single occasion or day has been a key marker of harmful drinking in general and clinical populations and has been widely used in alcohol epidemiology to capture the public health burden from alcohol use. Yet critics have raised the issue that the HED threshold fails to capture the impact of high-intensity drinking (HID) and implies the same average risks to all heavy drinkers regardless of whether they consume 5 or 15 drinks. Recent studies have raised attention to HID of consuming double (8+/10+ drinks) or even triple (12+/15+ drinks) the HED amount. As amounts per day reach extreme levels, risks for consequences and alcohol use disorders (AUD) increase greatly, even when average intake remains the same. This proposed Center project will trace trends in harmful drinking patterns with special attention to HID occurrence and rates over a 40-year period, identify a range of alcohol-related precursors and problems through event-based and population-based approaches, and situate harmful patterns within contexts to inform early screening and interventions for high-risk groups. We will employ sophisticated statistical methods to examine associations and consequences involved with HED and HID, using two adult general population and two heavy drinker event-based samples, each type of data designed to generate complementary and new knowledge about HID. We carry forward ARG's rich history in alcohol epidemiology and measurement expertise, and the Center mission to reduce alcohol-related disparities, in all our study aims. In response to NIAAA's priorities, and to ensure direct translational impact of study findings, we incorporate specific theory and practice for each study aim. Our definitions of HED/HID include both threshold (5+, 8+ and 12+) and amounts drunk in any day (from 5-7, 8-11, and 12+ drinks). Aim 1 takes a life course perspective to document harmful drinking trends over time from 1984 to 2024 and by priority groups (e.g., women; middle-aged to older adults; socially disadvantaged groups including racial/ethnic minorities and those with lower education; and people with history of AUD treatment or in recovery). Aim 2 characterizes event-level factors that heighten the risks for HID compared to HED levels. Sensitivity analyses will compare whether adjustments for drink size/strength and drinking rate (estimated BAC) will improve accuracy of how HID predict alcohol problems (e.g., AUD). Aim 3 situates harmful drinking patterns involving HID within the socioecological model to examine risk and protective factors both currently and across the life course that are strongly associated with HID. Also in Aim 3 we assess the extent that HID elevates the public health burden of AUD and other problems above that of HED and non-HED levels for all drinkers and priority groups using risk models and machine learning methods. Study findings will help identify key population subgroups and risk/protective factors that can support future development of targeted interventions at the event, individual, and environmental levels to reduce heavy and high-intensity drinking and their associated consequences.

PUBLIC HEALTH RELEVANCE This work will broaden our knowledge of both the precursors to and the outcomes of high-intensity drinking (HID) at various points over the life course, also estimating the public health burden attributable to high alcohol intake. This research project is poised to improve HID measurement, track HID trends over time, and enhance theory by contextualizing intensity within an individual's overall drinking pattern, drinking history, event-level characteristics, and individual and environmental influences. Finally, this research promises to aid in improving prevention and treatment strategies by better identifying suitable target subgroups (in particular women and disadvantaged populations disproportionately impacted by alcohol problems), and provide information to help shape design of future interventions aimed at reducing harmful drinking intensities among a range of adults, from young adults to middle-aged and older Americans.