High-intensity drinking and hours spent drinking.

BACKGROUND:High-intensity drinking (HID) is associated with negative consequences, but it remains unclear whether a time qualifier (i.e., time spent drinking) is needed to identify individuals at highest risk. To improve the measurement and conceptualization of HID, we examined the utility of adding a time qualifier to define what constitutes an occasion of HID using repeated daily surveys in a sample of young adults. METHODS:Participants were selected from a nationally representative sample of 12th-grade students in the United States who participated in the Monitoring the Future (MTF) study in Spring 2018. In 2019 and 2020, young adults (at modal ages 19-20) responded to annual and daily (14 consecutive days per year) online surveys about their alcohol use. RESULTS:When we compared moderate drinking days (less than 4/5 drinks for women/men), binge drinking days (4-7/5-9 drinks), and HID days (8+/10+ drinks), HID days had the longest duration of drinking (5.2 h), highest peak estimated blood alcohol concentration (eBAC, 0.30%), and greatest drinking pace (2.58 drinks/h). HID was associated with a greater number of negative consequences than either moderate or binge drinking; adjusting for time spent drinking did not impact this interpretation. HID was reported on 10.9% of days; when defined as 8/10+ drinks in 4 h or 2 h, HID was reported on 4.8% and 1.0% of days, respectively. Nearly all differences in eBAC and negative consequences persisted across drinking intensity despite the introduction of time constraints. CONCLUSIONS:HID days were characterized by both a longer time spent drinking and a more rapid pace of drinking. Adding a time qualifier to the definition of HID would restrict variability by only describing the minority of days and does not improve the distinctions among levels of risk.