Inequality in the socioeconomic burden and prognosis of multiple long-term conditions

Dramatic increases in life expectancy over recent decades, particularly amongst those in mid-life and older, has contributed to a greater prevalence of people living with multiple complex long-term conditions (MLTCs). Meeting the needs of those living with multiple long-term health conditions simultaneously represents a major concern for governments and is one of the biggest challenges facing the NHS. Recent large-scale studies using electronic health records in the UK estimate 23-27% of people have two or more conditions that are likely to have significant impact on need for treatment and reduced quality of life and account for over half of primary and secondary care utilisation and costs. However, existing evidence informing our understanding of MLTCs comes primarily from clinical samples or cross-sectional studies. Large-scale and rich longitudinal population data are required to better understand people's experiences of MLTCs - common and novel disease clusters and how they change over time - as well as the social and economic determinants of MLTC clusters, their impact on social and economic outcomes, service use and prognosis in terms of functioning, disability, quality of life and mortality. We anticipate inequality in the burden and prognosis of MLTC as evidence suggests that onset begins 10-15 years younger, on average for those living in socioeconomically disadvantaged areas compared with those living in more advantaged areas. Further inequality in the prognosis of MLTC, for example through differences in use or quality of services, is less well-known. The work of this project will address the following research questions:
1. What MLTCs cluster together and what clusters are less common?
2. To what extent are there social and economic inequality in onset and progression of MLTCs?
3. What is the long-term social, economic and wellbeing burden associated with membership of different MLTC clusters in terms of physical, cognitive and social functioning, wellbeing and mortality?
4. Amongst those who live with MLTCs, are there social or economic inequalities in access to or quality of health care (such as the balance of planned and unplanned care, referrals to specialist care)?
This project will use the rich, longitudinal, multidimensional data of the English Longitudinal Study of Ageing (ELSA) linking with Hospital Episode Statistics (HES), mortality records. As a nationally representative longitudinal multidisciplinary panel study of older people in England, ELSA is the ideal data set for this project. ELSA has collected high quality data about the biological, health, economic, and social experiences every two years from a sample of over 12,000 people aged 50+ in 2001, with 9 waves of data currently available. Recently ELSA was linked with NHS hospital admissions (HES) and cancer registry data. While previous studies have used electronic health records to study multimorbidity, ELSA allows for the inclusion of information on social and economic circumstances and severity of conditions.
The project will make use of advanced statistical techniques to analyse the repeated assessments of ELSA and to exploit the linkage to HES and mortality data. Data from the main interviews on health conditions will be used to identify clusters of MLTCs and their changes over time using latent class analysis and latent trajectory analysis. Social and economic characteristics of those with MLTCs will be evaluated using data from the main ELSA interviews, covering a wealth of information on participant's circumstances and changes over time therein. The burden associated with multimorbidity will be evaluated longitudinally using mixed effects models. The measures under consideration are depression and quality of life (wellbeing), economic circumstances (income, wealth and labour market participation, receipt of universal credits), social (loneliness, receipt of informal care, social contacts and relationships), health and social ca