New ISER research using Understanding Society data has suggested that health inequalities are larger between households than between individuals, highlighting the importance of targeting potential health policies at couples rather than individuals. The new research, co-authored by Dr Apostolos Davillas with Professor Stephen Pudney from the University of Sheffield, has been published in the Journal of Health Economics.
It is often assumed that partners who live together influence each other’s lifestyle choices, e.g. physical activity, eating habits, etc., but relevant research has also suggested that people often seek partners that have the same socio-economic characteristics as them (“homogamy”), probably implying similar health statuses.
The new study seeks to distinguish non-causal correlation due to homogamy from potentially causal effects of shared lifestyle and environmental factors to explore the underlying sources of the concordance of health states within couples. Using data from Understanding Society, this new study has shown that both homogamous partner selection and causal shared lifestyle make roughly equal contributions to the concordance of health states observed within couples.
The research made use of Understanding Society’s self-reported health data and biomarkers which gave a maximum sample of 12,881 couples.
Dr Apostolos Davillas said: “These findings are relevant to public policy and the capacity of couples to absorb adverse shocks. Even if health selection occurs at the time of partnership formation (homogamy), a causal effect of the shared environment is necessary for health concordance to persist or increase through time. We find that shared lifestyle factors and homogamous partner selection make roughly equal contributions to the concordance of health states in couples. This matters for policy because persistent concordance may result in wider health inequalities across couples and any tendency for disability and morbidity to become more concentrated within couples also affects the social cost of disease.
“Separating homogamy from causal concordance may be also relevant for public health prevention programs. Although homogamous health selection is largely immune to policy, evidence on causal effects of shared environment and lifestyle may provide a basis for screening programmes and other interventions that exploit information on the health of one partner to identify elevated risks for the other partner.”
Concordance of health states in couples: Analysis of self-reported, nurse administered and blood-based biomarker data in the UK Understanding Society panel by Apostolos Davillas and Stephen Pudney is published in the Journal of Health Economics
Volume 56, December 2017