The International Alcohol Control (IAC) study is a newly developed international collaborative project designed to collect comparative data on alcohol consumption and policy-relevant behaviors in both high- and middle/low-income countries. Initial member countries New Zealand, Thailand, South Korea, Scotland, and England have recently been joined by Mongolia, Australia, South Africa, Peru, St. Kitts, and Vietnam. This study of the purchasing behavior of respondents in New Zealand – a high-income country – from on- and off-premise outlets, found that heavier drinkers were more likely to buy cheaper alcohol from off-premise outlets, and purchase at later times.
Results will be published in the May 2014 online-only issue of Alcoholism: Clinical & Experimental Research and are currently available at Early View.
"The idea for the IAC study came in part from the International Tobacco Control study," explained Sally Casswell, director of Social and Health Outcomes Research and Evaluation (SHORE) at Massey University in Auckland, New Zealand, and corresponding author for the study. "There is a similar need in the alcohol field to develop more reliable ways to evaluate policy as it relates to alcohol control, and the IAC longitudinal survey and cross-country dimensions provide this. This project – designed to allow for comparable data collection over time and across countries, and collecting data on policy-relevant variables as well as consumption – provides a much more valuable starting point for beginning alcohol researchers." New Zealand was the first to use the IAC study survey instrument in 2011, she noted.
"The IAC study is in particular a landmark effort to test the effects of various alcohol policies on alcohol consumption and problems in low- and middle-income countries," added David H. Jernigan, associate professor at Johns Hopkins Bloomberg School of Public Health. "The bulk of our present-day evidence comes from high-income countries, and there are questions about how transferable policy solutions may be; this study will help address those questions. While it would be ideal if the US were involved in the IAC, simply for reasons of comparability, what is more important is that low- and middle-income countries participate, since this is where we lack evidence."
Casswell and her colleagues conducted their survey between July and October 2011 among a nationally representative sample of drinkers (n=1,900 drinkers aged 18 years and older). Interview data included place and time of purchase, amounts purchased, price paid, and consumption details (beverage and location specific). Analysis was performed on relationships between policy-relevant variables and consumption, incorporating demographic variables, and further validated by government data on alcohol available for consumption, aggregate expenditures, and prices from the Consumer Price Index.
"Our analysis of the relationship between the prices people told us they paid and how much they drank found that people drinking large quantities pay less for their drinks," said Casswell. "Those paying lower prices from off-license premises – where most alcohol is sold in New Zealand – were more likely to be daily drinkers; whereas prices paid in on-premise drinking locations, like bars and restaurants, were not linked to frequency of drinking, only to quantity. The survey also showed the heavier drinkers in the survey – both in terms of the quantities consumed and the frequency of drinking – were more likely to have purchased alcohol in later hours. The validity of our survey responses is very important. Most previous surveys have under-estimated the amount of alcohol consumed by about 40 to 50 percent, whereas our method accounts for almost all of the alcohol being consumed in the country. Similarly, the prices reported were accurate, judged against the data available."
Jernigan agreed that this study effectively addressed two issues that have vexed researchers concerning the validity of survey research on alcohol. "One, surveys have been plagued by persistent under-reporting of consumption; by using a beverage and location-specific method for assessing respondents' consumption, this survey comes very close to covering all the actual consumption in the country as demonstrated by sales data," he said. "Two, this study shows that respondents can answer questions about the price they paid for alcohol with reasonable accuracy."
"These results have important implications for local governments as well as communities," said Casswell. "It is the communities that have to deal with alcohol-related disorders and violence, which are linked to heavier drinking which is, in turn, linked to longer hours spent drinking in bars and pubs. Sales from off-license premises of takeaway alcohol have also been linked with family violence and child maltreatment. Our findings support the importance of trading hours, and this is one policy which may be changed quickly – unlike reducing density, for example, which may take longer to achieve."
"These findings are more relevant to policy makers than to clinicians," said Jernigan, "by pointing to the importance of limiting the hours of the sale of alcohol. These results are suggestive of something that has been demonstrated over and over again in the alcohol-research literature: the more available alcohol is, the more likely that people will drink heavily. At a more fundamental level, science relies on replication of results. This study is the first step towards producing replicable results regarding the effectiveness of alcohol policies in low- and middle-income countries. It is more important as a harbinger of the validity of what is to come than in its own findings."
"With this research, we are seeking to better inform community policy in the countries taking part [in the IAC study] about what is happening on the ground – what drinkers are buying, or obtaining via social supply, how much they are paying, where and when they buy, and their exposure to alcohol marketing," said Casswell. "An ability to measure response to any policy changes which occur, and make comparisons with countries where no policy change has occurred, will add to the international community's knowledge of what makes effective alcohol policy, particularly in emerging alcohol markets where less information is available."