Abstract
Aims: To investigate the relationship between several indicators of socio-economic status and drinking patterns in young adulthood.
Design: Data collected in a longitudinal study of young adults was analysed using repeated measures models to examine the relationship between income, occupational activity and educational achievement and patterns of drinking.
Setting: These data were collected as part of a longitudinal study of a birth cohort of New Zealanders. They were interviewed for the most part in a central location using face to face method and a computer assisted alcohol interview.
Participants: The participants were members of the Dunedin Multidisciplinary Health and Development Study aged 18, 21 and 26. Nine hundred and sixty nine study members contributed to the analysis. Study members have been found to be broadly representative of the New Zealand population and cross national studies suggest findings are generalisable to other similar market economies.
Measurements: Three indicators of socio-economic status were used; educational achievement, occupational activity and income. The educational achievement indicator at age 18 had three levels that ranged from no school qualifications to higher school qualifications. For age 21 two additional categories of tertiary educational achievement were included to make five categories and for age 26 higher tertiary degrees were included in the measure to make six categories. Five categories of occupational activity were used: unemployed; student; employed in higher status occupation; employed in lower status occupation; and homemakers/unpaid workers. Income data was also used. Two measures of alcohol consumption were used. These were the frequency of drinking and the typical quantity of alcohol consumed per drinking occasion in the past year. Both of these measures were computed from a series of five location-specific questions.
Findings: Frequency of drinking increased over these early adult years and the quantities consumed peaked at age 21 and decreased thereafter for both males and females. Frequency of drinking during these years was influenced by income with the higher income respondents drinking more often and this was persistent overtime. Quantity of drinking was most influenced by educational achievement. The less well educated young adult drank significantly more during a drinking occasion and at all ages (18, 21 and 26). There was also a relationship between educational achievement and frequency of drinking for males at age 18 and a relationship between women’s occupational activity and the quantities they consumed.
Conclusions: The quantities of alcohol consumed and the frequency of drinking had different relationships with measures of socio-economic status. Those with fewer educational qualifications had heavier drinking occasions. More frequent drinking was more common among those with higher income but income had no relationship with the quantities consumed. The finding that the dimensions of drinking operate differently explains the lack of consistency in previous research which has investigated socio-economic status and the volumes of alcohol consumed. The findings of higher quantities consumed among those of lower social status may explain some of the reduced life expectancy found among those with lower socio-economic status.