The physical functioning and mental health of informal carers: evidence of care‐giving impacts from an Australian population‐based cohort

Informal carers represent a substantial proportion of the population in many countries and health is an important factor in their capacity to continue care‐giving. This study investigated the impact of care‐giving on the mental and physical health of informal carers, taking account of contextual factors, including family and work. We examined health changes from before care‐giving commenced to 2 and 4 years after, using longitudinal data from the Household Income and Labour Dynamics in Australia survey. The sample comprised 424 carers and 424 propensity score‐matched non‐carers. Health was self‐assessed, measured with the SF‐36 Health Survey Mental Health (MH) and Physical Functioning (PF) scales. Care‐giving was classified as non‐carer, low (<5 hours/week), moderate (5–19 hours/week) and high (20 or more hours/week). PF and MH change scores were regressed on baseline scores, care‐giving, covariates (including work, family and socio‐demographic characteristics) and interactions to identify impacts for subgroups. The physical and mental health impacts differed by gender, and care‐giving hours and carer work hours were important contextual factors. Deterioration in both PF and MH was worse for females after 2 years and deterioration in MH was worse for males after 4 years. Among carers aged 40–64 years, there was a 17‐point decline in PF (P = 0.009) and a 14‐point decline in MH (P < 0.0001) after 2 years for female high caregivers working full‐time and 9.3 point improvement (P = 0.02) for non‐working male high caregivers. Change was not significant for non‐carers. The study found that not all carers suffer adverse health impacts; however, the combination of high levels of care‐giving with workforce participation can increase the risk of negative physical and mental health effects (particularly in female carers). Working carers providing high levels of care represent a vulnerable subgroup where supportive and preventive services might be focused.