Methods

The International Alcohol Control (IAC) Policy Evaluation Study is a multi-country collaborative research project measuring the impacts of key national level alcohol control policies. The design of the IAC study is modelled on the International Tobacco Control Project (itcproject.org).

The IAC study design allows for comparison across countries and can assess changes in drinking behaviour before and after policy changes to evaluate alcohol control policies. The objectives of the IAC study are to inform local policy development and implementation and to allow rigorous evaluation of the impacts of national-level alcohol control policies in each of the participating countries. The overall aim is to reduce alcohol related harm by strengthening the development and implementation of effective alcohol policy.

Longitudinal Survey

The IAC longitudinal survey is the first international cohort study examining alcohol use and policy relevant behaviours. Replenishment samples are also added to ensure representative samples are maintained to compensate for attrition of the sample. The IAC survey is a complex survey and is designed to be computer assisted. Data are collected using computer assisted telephone interviews (CATI), in face to face interviews using a netbook, PDA or similar device, or as a web based survey.

The alcohol consumption measures are location and beverage specific and have been adapted for use in different alcohol markets and drinking cultures. This approach has been found to account for high levels of alcohol consumed in a country. This approach collects data on both commercial beverages and informal and illicit beverages. Measures of policy relevant behaviours such as information about the prices paid for alcohol beverages have also been found to be valid.

Alcohol Environment Protocol

The Alcohol Environment Protocol (AEP) assesses the alcohol environment in which the IAC survey participants live. The AEP is based on administrative and commercial data sets, key informant interviews and observational studies to assess the implementation of effective alcohol control policies in the following areas: alcohol availability, pricing and taxation of alcohol products, social supply of alcohol, alcohol marketing, and drink driving enforcement.

The objectives of the AEP are to inform the development of survey instruments and contextualise interpretation of the survey data in each of the countries. It also allows comparison of the alcohol environment in very different alcohol markets and cultures.

Cross country comparison

The IAC survey and AEP include key measures for policy domains that are identical or functionally similar across countries to facilitate cross-country comparisons. The evaluation studies take advantage of natural experiments created when a country, or locality, implements a policy; changes in policy relevant variables in that country from pre- to post-policy survey waves will be compared to other countries where that policy has not changed. This research design provides high levels of internal validity, allowing more confident judgments regarding the possible causal impact of the policy.

An overview of the study design is available here.