Methods for calculation of per capita alcohol consumption in a Muslim majority country with a very low drinking level: Findings from the 2011 Iranian mental health survey

Introduction and Aims: There is a paucity of data on volume of alcohol use from Muslim majority countries. We aimed to present estimation methods for alcohol consumption with the use of survey data for these societies and provide an estimation for age 15+ per capita consumption of pure alcohol for Iran. Design and Methods: The Iranian Mental Health Survey was a nationally representative household survey on individuals aged 15-64years, with a multistage, cluster sampling design. We used the 'Last Week' method and 'Quantity-Frequency' methods for gathering data on alcohol consumption and combined these to provide more complete estimates. Results: The response rate was 85.7%. From the total of 7840 respondents, 5.7% and 1% reported past 12months and past week alcohol use, respectively. The highest estimation for age 15+ per capita consumption of pure alcohol was yielded by the 'combination method' (0.108 L ethanol/person/year) followed by the Quantity-Frequency method (0.079L). The 'Last Week' method provided the lowest estimate (0.059L). Discussion and Conclusions: Unlike in surveys of non-Muslim countries, frequency of drinking from recent recall (last week) was much lower than from recall of usual drinking in the last year. We conclude that 0.108L (SE= 0.03) is the best survey-based estimate of age 15+ per capita consumption, which translates to about 5 750 000L of national consumption per year in Iran. However, this method is still likely to under-estimate per capita consumption due to evidence of under-reporting in the survey.