Age differences in the associations between sick leave and aspects of health, psychosocial workload and family life: a cross-sectional study.

Objectives: To investigate differences in associations between sick leave and aspects of health, psychosocial workload, family life and work-family interference between four age groups (<36, 36-45, 46-55 and 55+ years).

Design: A cross-sectional study; a questionnaire was sent to the home addresses of all employees of a university.

Setting: A Dutch university.

Participants: 1843 employees returned the questionnaire (net response: 49.1%). The age distribution was as follows: <36: 32%; 36-45: 26%; 46-55: 27% and 55+: 12%.

Primary Outcomes: Frequent sick leave (FSL, ≥3 times in the past 12 months) and prolonged sick leave (PSL, >2 weeks in total in the past 12 months). Differences between the age groups in independent variables and outcomes were investigated. Logistic regression analysis was used to calculate associations between various variables and the sick leave outcomes. Interaction terms were included to detect differences between the age groups.

Results: Age differences were found for many work- and family-related characteristics but not in the mean scores for health-related aspects. Presence of chronic disease was reported more frequently with increasing age. The 55+ age group had almost two times less chance of FSL, but 1.6 times more chance of PSL than the <36 age group. Age moderates the associations between career opportunities, partner's contribution in domestic tasks and sex, and FSL. Job security and pay, support from supervisor, challenging work and being breadwinner have different associations with PSL. However, life events in private lives and perceived health complaints are important in all age groups. FSL and PSL have some determinants in common, but there are differences between the outcomes as well.

Conclusions: Age should be treated as a variable of interest instead of a control variable. Employers and occupational physicians need to be aware that each phase in life has specific difficulties that can lead to FSL and PSL.