Work-family conflicts and subsequent sleep medication among women and men: a longitudinal registry linkage study.

Work and family are two key domains of life among working populations. Conflicts between paid work and family life can be detrimental to sleep and other health-related outcomes. This study examined longitudinally the influence of work-family conflicts on subsequent sleep medication. Questionnaire data were derived from the Helsinki Health Study mail surveys in 2001-2002 (2929 women, 793 men) of employees aged 40-60 years. Data concerning sleep medication were derived from the Finnish Social Insurance Institution's registers covering all prescribed medication from 1995 to 2007. Four items measured whether job responsibilities interfered with family life (work to family conflicts), and four items measured whether family responsibilities interfered with work (family to work conflicts). Cox proportional hazard models were fitted, adjusting for age, sleep medication five years before baseline, as well as various family- and work-related covariates. During a five-year follow-up, 17% of women and 10% of men had at least one purchase of prescribed sleep medication. Among women, family to work conflicts were associated with sleep medication over the following 5 years after adjustment for age and prior medication. The association remained largely unaffected after adjusting for family-related and work-related covariates. Work to family conflicts were also associated with subsequent sleep medication after adjustment for age and prior medication. The association attenuated after adjustment for work-related factors. No associations could be confirmed among men. Thus reasons for men's sleep medication likely emerge outside their work and family lives. Concerning individual items, strain-based ones showed stronger associations with sleep medication than more concrete time-based items. In conclusion, in particular family to work conflicts, but also work to family conflicts, are clear determinants of women's sleep medication.