In England and Canada, socioeconomic disadvantage is associated with poorer physical function and greater declines as people age, according to a study published August 13 in the open-access journal PLOS Medicine. The study was led by Stephanie Schrempft of Geneva University Hospitals, Switzerland, and colleagues.
Physical function naturally declines with age, but the rate of decline varies considerably between individuals and populations. Wealth is known to influence health and disability, yet few studies have directly compared patterns of functional ageing across countries. Such comparisons can help researchers understand how social policies and broader structural factors may contribute to inequalities in healthy ageing.
To investigate these differences, researchers analysed data from two major longitudinal studies: 8,511 participants in the English Longitudinal Study of Ageing and 22,605 participants in the Canadian Longitudinal Study on Aging. Participants were between 50 and 85 years old. The researchers examined wealth in relation to walking speed, grip strength, lung function, hearing, mobility, and difficulties performing daily activities such as dressing, bathing and eating.
People with less wealth generally had poorer physical function and experienced greater declines in mobility and their ability to perform daily activities as they aged. Importantly, socioeconomic inequalities in functional ageing were substantially greater in England than in Canada. These differences remained even after researchers accounted for chronic health conditions, weight status and behaviours such as smoking.
The size of the wealth gap was particularly striking for walking speed. In England, the least wealthy 60-year-olds had walking speeds comparable to those of the wealthiest 75-year-olds—an apparent functional ageing difference of approximately 15 years. In Canada, the corresponding difference was about nine years, suggesting meaningful differences in socioeconomic inequalities between the two countries.
The study also identified important differences between women and men. Women with the least wealth experienced greater difficulties with mobility and daily activities than men in the same socioeconomic group, although they had better lung function. These findings demonstrate that socioeconomic disadvantage does not affect everyone in the same way and highlight the value of considering both wealth and sex when studying healthy ageing.
Senior author Silvia Stringhini said the researchers were particularly struck by the substantially larger wealth gaps in England than in Canada. Despite both countries having universal healthcare and similar levels of income inequality, the differences in functional ageing were considerable. She noted that ongoing cross-country research will investigate the structural factors that may explain why these inequalities differ between countries.
First author Stephanie Schrempft emphasised that the findings go beyond showing that people with less wealth have poorer health on average. By following adults over time in England and Canada, the researchers found that socioeconomic disadvantage was also associated with a faster loss of mobility and physical independence with age. Although the study was observational and could not establish causation or fully account for factors such as childhood circumstances and access to private healthcare, the authors suggest that healthy-ageing policies should prioritise socioeconomically disadvantaged populations and address the broader structural conditions underlying these inequalities.
More information: Stephanie Schrempft et al, Socioeconomic inequalities in functional ageing trajectories in England and Canada: A comparative longitudinal cohort study, PLOS Medicine. DOI: 10.1371/journal.pmed.1004833
Journal information: PLOS Medicine Provided by PLOS
