Impact of Different Reference Period Definitions in the Quantification of Alcohol Consumption: Results from a Nationwide STEPS Survey in Mozambique

Aims: To compare the estimates of alcohol consumption in Mozambique obtained with different reference period definitions. This is a critical methodological aspect when measuring alcohol consumption and its impact is likely to vary across settings.

Methods: A nationally representative sample of 3264 Mozambicans aged 25-64 years was evaluated in a community-based cross-sectional study conducted between September and November 2005. Face-to-face interviews were conducted following the World Health Organization-Stepwise approach to Surveillance methodology. The amount of alcohol consumed was estimated among current drinkers, using the previous week (1W) and the 12 months (12M) prior to the data collection as the reference.

Results: Among drinkers, the prevalence of consumption of >14 drinks/week was higher in men (12M: 18.6 vs. 7.8%; 1W: 16.3 vs. 6.1%), although the prevalence of excessive weekly intake (>7 drinks for women and >14 drinks for men) was higher among women (12M: 25.9 vs. 18.6%; 1W: 18.1 vs. 16.3%). The concordance between the reported intakes according to the reference period was low (κ = 0.25).

Conclusion: In this setting where alcohol consumption is a male-dominated behaviour, among drinkers the prevalence of gender-defined excessive amounts was higher in women. The concordance between different recall periods was low and this needs to be taken into account when comparing results from different studies.