International alcohol control study: pricing data and hours of purchase predict heavier drinking.

BACKGROUND: This study reports findings from the International Alcohol Control (IAC) study that assesses the impact of alcohol control policy on consumption and policy-related behaviors. Modeled on the International Tobacco Control study that uses longitudinal surveys with comparison between countries, the baseline survey was carried out in New Zealand. This study reports analysis of the purchasing behavior respondents report separately for on- and off-premise outlets, providing validation data for both alcohol consumption and reported prices.

METHODS: New Zealand is a high-income country with an adult per capita alcohol consumption (as of 2011) of 9.5 l. The survey was carried out among a nationally representative sample of drinkers. Interview data on place and time of purchase, amounts purchased, price paid, and consumption (beverage and location specific) was collected. Relationships between policy relevant variables and consumption were modeled taking into account demographic variables. Validation was provided by government data on alcohol available for consumption, aggregate expenditure and prices from the Consumer Price Index.

RESULTS: Drinkers paying low prices at on- or off-licensed premises had higher odds of consuming 6+ drinks on a typical occasion, as did drinkers purchasing alcohol at later times. Regarding frequency, drinkers purchasing at later times were more likely to be daily drinkers. Lower price in off licenses but not on licenses predicted daily drinking. The data collected accounted for approximately 96% of alcohol available for consumption and the prices accounted for 98% of aggregate expenditure.

CONCLUSIONS: Valid survey data were collected to give an accurate picture of alcohol consumption and prices paid by drinkers. Heavy drinkers were more likely to buy cheaper alcohol and purchase at later times; 2 policy issues under discussion in many settings. This analysis suggests the IAC study that has the potential to provide data to contribute to the debate on appropriate policy responses to reduce alcohol-related harm.