Aims To examine the associations between working hours and alcohol-related problems during early adulthood.
Design and setting Longitudinal study of a birth cohort born in Christchurch, New Zealand in 1977 and studied to age 30.
Participants A total of 1019 participants with data available for working hours and alcohol-related problems at either age 25 or 30.
Measurements Weekly working hours in paid employment; frequent alcohol use; diagnosis of alcohol abuse/dependence; number of symptoms of alcohol abuse/dependence. Associations between working hours and alcohol-related problems were adjusted for covariates including measures of: parental and family background; personality and behaviour; IQ and educational achievement; recent negative life events; recent mental health problems; and current partner and family circumstances.
Findings Longer work hours were associated significantly with more frequent alcohol use (P < 0.0001), higher rates of alcohol abuse/dependence (P = 0.0001) and a greater number of alcohol abuse/dependence symptoms (P = 0.01). These associations were adjusted for a wide range of confounding factors. After adjustment there remained significant (P < 0.05) associations between working hours and alcohol-related problems, with those working 50 or more hours per week having rates of alcohol-related problems 1.8–3.3 times higher than those who were not working. The associations between work hours and alcohol use were similar for males and females.
Conclusions Longer work hours appear to be associated with higher rates of alcohol-related problems, including more frequent alcohol use, higher rates of alcohol abuse/dependence and a greater number of alcohol abuse/dependence symptoms. These associations remain even after extensive adjustment for confounding.