Working informal caregivers and risk of long-term sickness absence and unemployment: a Danish nationwide cohort study of effect modification by psychosocial working conditions

Aim Balancing work and informal-care responsibilities is burdensome. We examine the risk of long-term sickness absence (LTSA) and unemployment among working caregivers of children with versus without mental disorders. We tested modification by occupational emotional demands and influence. Subject and methods This register-based matched cohort-study used LTSA and unemployment data on 1,927,098 Danish caregiver-child pairs, tracking incidence of child mental disorders (2000–2018). Exposure to occupational emotional demands and influence at baseline were assigned by job-exposure matrices. Mental disorders were indicated by psychiatric hospital contact, drug use or treatment for substance abuse. Caregivers of children with and without mental disorders were matched 1:5 by age, sex (child/caregiver), occupation, working hours (caregiver), and baseline calendar-week. Cox models estimated hazard ratios (HR) of LTSA (≥ 4 weeks) or unemployment with 10-year follow-up. LTSA and unemployment were analyzed separately, stratified by caregiver sex. Analyses were adjusted for socio-demographics. We tested effect modification and estimated relative excess risk due to interaction (RERI). Results Caregivers of children with any mental disorder had higher risk of LTSA (females: HR = 1.96, 95% CI = 1.94;1.98, males: HR = 1.63, 95% CI = 1.60;1.65) and unemployment (females: HR = 1.14, 95% CI = 1.12;1.15, males: HR = 1.14, 95% CI = 1.12;1.16). The RERI for LTSA was elevated among caregivers exposed to high emotional demands (females: 0.34, 95% CI = 0.28;0.40, males: 0.06, 95% CI < 0.01;0.12) or low influence (females: HR = 0.19, 95% CI = 0.14;0.24, males:HR = 0.12, 95% CI = 0.07;0.18). Conclusion Working caregivers of children with mental disorders have increased risk of LTSA and unemployment. Societal and workplace initiatives, e.g., targeting working conditions, may help balance informal-care and work responsibilities.