A Review of the Validity and Reliability of Alcohol Retail Sales Data for Monitoring Population Levels of Alcohol Consumption: A Scottish Perspective

Aims: To assess the validity and reliability of using alcohol retail sales data to measure and monitor population levels of alcohol consumption. Methods: Potential sources of bias that could lead to under- or overestimation of population alcohol consumption based on alcohol retail sales data were identified and, where possible, quantified. This enabled an assessment of the potential impact of each bias on alcohol consumption estimates in Scotland. Results: Overall, considering all the possible sources of overestimation and underestimation, and taking into account the potential for sampling variability to impact on the results, the range of uncertainty of consumption during 2010 was from an overestimate of 0.3 l to an underestimate of 2.4 l of pure alcohol per adult. This excludes the impacts of alcohol stockpiling and alcohol sold through outlets not included in the sampling frame. On balance, there is therefore far greater scope for alcohol retail sales data to be underestimating per adult alcohol consumption in Scotland than there is for overestimation. Conclusion: Alcohol retail sales data offer a robust source of data for monitoring per adult alcohol consumption in Scotland. Consideration of the sources of bias and a comprehensive understanding of data collection methods are essential for using sales data to monitor trends in alcohol consumption.