Setting a Cap on the Maximum Average Number of Drinks Per Day in Australian Survey Research

Aims: The aim of this study is to assess the impact of the cap level on total consumption and a range of variables including negative consequences. Design, Setting, and Participants: Cross sectional survey in Australia with 2,020 Australians aged 16 and over. Measures: Participants completed a detailed survey on their alcohol consumption with no methodological limit on consumption. Findings: Setting a cap on high levels of consumption can significantly decrease the mean level of consumption. While the relationship between consumption and related variables do not change significantly, the relationship with negative consequences strengthens as the cap lowers, and the relationship with purchases decreases for uncapped data and data with low caps, providing some guidance on where a cap would be best placed. Conclusions: Consideration of where to set a maximum daily consumption level in survey research should be not only based on what could be feasibly consumed, but also on the point at which a very high reported consumption level is more likely to have been reported in error than as a reflection of reality. Checking the relationship between consumption and related variables, with different caps applied before selecting a capping level, is recommended.