Combinations of Drinking Occasion Characteristics Associated With Units of Alcohol Consumed Among British Adults: An Event-Level Decision Tree Modeling Study
Abstract
Background
Alcohol consumption is influenced by the characteristics of alcohol use occasions, for example, location, timing, or the composition of the alcohol use group. However, the relative importance of occasion characteristics is not yet well understood. This study aims to identify which characteristics, and combinations of characteristics, are associated with units consumed within alcohol use occasions. It also tests whether accounting for occasion characteristics improves the prediction of consumption compared to using demographic information only.
Methods
The data come from a cross-sectional, nationally representative, online market research survey. The sample includes 18,409 British alcohol users aged 18 + who recorded the characteristics of 46,072 alcohol use occasions using 7-day retrospective alcohol use diaries in 2018. The study used decision tree modeling and nested linear regression to predict units consumed in occasions using information on alcohol use location/venue, occasion timing, company, occasion type (e.g., a quiet night in), occasion motivation, alcohol type and packaging, food eaten and entertainment/ other activities during the occasion. The researchers estimated models separately for 6 age-sex groups and controlled for usual alcohol use frequency, and social grade in nested linear regression models.
Results
Our 6 final models accounted for between 55% and 71% of the variance in alcohol use occasion alcohol consumption. Beyond demographic characteristics (1 to 9%) and occasion duration (24 to 60%), further occasion characteristics and combinations of characteristics accounted for 31 to 70% of the total explained variance. The characteristics most strongly associated with heavy alcohol consumption were long occasion duration, consuming spirits as doubles, and consuming wine. Spirits were also consumed in light occasions, but as singles. This suggests that the serving size is an important differentiator of light and heavy occasions.
Conclusions
Combinations of occasion duration and alcohol type are strongly predictive of alcohol consumption in adults’ alcohol use occasions. Accounting for characteristics of alcohol use occasions, both individually and in combination, substantially improves the prediction of alcohol consumption.