The relationship between age at drinking onset and subsequent binge drinking among women.

BACKGROUND To examine the association between age at drinking onset and subsequent binge drinking, and to examine whether there are differences in this association between four countries. METHODS The data consisted of 68,539 women aged 18-47 years randomly selected from the general population in Denmark, Iceland, Norway and Sweden. Frequency of binge drinking, defined as consuming >6 U of alcohol at the same occasion once or more per month, and age at drinking debut were assessed through a questionnaire survey. RESULTS Overall, 12-26% reported binge drinking once or more per month in the four countries. Median age for starting drinking was 16 years in all four countries. Women who started drinking at 14 years or younger were significantly more likely to binge drink than women who started drinking at 19 years or older with adjusted odds ratios of 2.9 (95% confidence intervals 2.3-3.7), 2.8 (2.1-3.6) and 2.6 (1.9-3.4) for binge drinking in Denmark, Iceland and Sweden, respectively. Among Norwegian women the association was stronger with an adjusted odds ratio at 4.4 (3.5-5.6). The association in all four countries was more pronounced in women younger than 30 years than in older women. CONCLUSION In the four Nordic countries, there is a strong relation between age at drinking onset and later binge drinking. The strong relationship found in countries with such different alcohol cultures is most likely generalizable to other Western countries.