Disability, informal and formal support, and psychological health in later life : a cross-sectional and longitudinal examination

Abstract

This thesis examines the relationships between disability, informal and formal instrumental support, and psychological health in later life. Specifically, it addresses three questions cross-sectionally and longitudinally: (a) what factors are associated with the type of support received (no support, informal support only, formal support only or both informal and formal support), with a focus on the determinants of formal support in isolation? (b) does the type of support received (informal and/or formal support) differentially buffer the harmful association between disability and psychological health? and (c) do the stress-buffering effects of enacted support strengthen in later life with advancing age? To address these three research questions, data are drawn from the Australian Longitudinal Study of Ageing. The sample comprises 1961 community{u00AC}dwelling individuals aged 65 years or over at Wave 1; 1518 at Wave 3 and 666 at Wave 6. Results from the first research question show that only a small proportion of older adults rely solely on formal support in isolation over time. Further, results indicate that increases in functional limitations over time are associated with higher odds of transitioning from receiving formal support only to receiving both informal and formal support, compared with remaining a formal-only recipient. Overall, the results suggest that assistance received from formal sources only may not be sufficient to meet extensive health needs. Findings are both consistent with the theory of complementarity and suggest that it may need to be refined to encompass the proposition that informal support may be drawn upon to supplement existing formal support as physical health needs increase. In relation to the second research question, results show that receiving (a) informal support only and (b) both informal and formal support are associated with weaker relationships between functional limitations and depressive symptoms and life satisfaction relative to the receipt of no support. There is also a trend that suggests receiving formal support only provides a buffering effect against disability for life satisfaction but not depressive symptoms. However, a closer examination of the results reveal that this moderating effect is driven by an adverse association between receipt of formal support in isolation and life satisfaction for individuals with minimal functional limitations, rather than a protective effect. These findings highlight the importance of informal instrumental support in later life and suggest that the receipt of formal support in isolation may not be sufficient to meet an individual's physical health needs. Results from these analyses also show that receiving instrumental support for individuals with no or minimal functional limitations are generally associated with poorer psychological health. This unexpected finding emphasises the complex interrelationships between disability, instrumental support and psychological health and cautions us against assuming that support is always beneficial. In regards to the third research question, longitudinal results lend support to the stress-buffer age-variation hypothesis, which posits that the protective influence of enacted support strengthens with advancing age in later life. This finding highlights the importance of social relationships in later life and has important implications for service provision. Specifically, the results are consistent with socioemotional selectivity theory and suggest that informal aspects of the provider-receiver relationship such as continuity of care may be particularly beneficial for older adults. Show more