Abstract
Background: National surveys have been used to measure alcohol consumption patterns and some aspects of alcohol related harm, but do not tell us much about the role of alcohol in social networks. Understanding the drinking patterns of intimate partners and social influences on drinking may help us understand alcohol’s contribution to satisfaction, disorder, and violence in families.
Aim: To describe 1.Patterns of drinking in the adult population, by key demographic characteristics; 2.Similarities and differences in drinking between intimate partners; 3.The experience of informal social controls on drinking.
As this research relies on survey data, an important aspect of the work was to assess the impact of incomplete response on the findings.
Methods: Data were collected in a cross-sectional nationally representative survey of 18 – 70 year olds, conducted in 2007 as part of Gender, Alcohol and Culture: an International Study (GENACIS). This postal survey of a sample from the combined electoral roll, used a questionnaire designed by the International Research Group on Gender and Alcohol (IRGGA) adapted for New Zealand conditions. Standard descriptive statistics have been used, along with logistic regression models to estimate associations between variables while controlling for confounders. Potential non-response bias was investigated by comparing known characteristics of respondents and non-respondents, comparing early, intermediate and late respondents, and comparing key findings with other national surveys of alcohol use.
Results: The survey had a response rate of 49.5%. Men, people of Maori ethnicity, people living in high deprivation areas, and young adults were less likely to respond to the survey. Late respondents were more like non-respondents in terms of demographics and more likely to be binge drinkers, suggesting binge drinking was underestimated in the survey.
Most of the sample were current drinkers (12 month prevalence 89.6%), and prevalence of drinking decreased with age. Men were more likely to be identified as binge drinkers, along with the youngest age group, those of Maori descent, people classified as never married and people living in the most deprived areas.
Most intimate partnerships (86%) differed in drinking frequency by less than 2 points, and 58% of partnerships differed in typical quantity per occasion by only 1-5 drinks. The more time couples spent drinking together the more concordant they were for both drinking frequency and quantity of alcohol per occasion. Higher concordance for alcohol per occasion was associated with higher reporting of happiness with the relationship.
Pressure to drink less, came most commonly from family and spouses, rather than friends, workmates or health professionals. Binge drinkers of both sexes, and young men in general, were the most likely groups to have experienced this type of pressure.
Pressure to drink more was most common in the youngest age group (60.1%), and decreased with age. Binge drinkers were most likely to experience pressure to drink more of all drinker status groups (OR=2.7 relative to lifetime abstainers).
Conclusions: This study provides new insights into drinking patterns by gender and relationship status. It provides information about drinking within relationships and what informal controls are operating. This helps identify groups and situations at higher risk of alcohol-related harm. However, longitudinal research would be required to reveal whether the associations identified in this study might be causal, and where appropriate interventions might be focused.