Original articleContribution of socioeconomic position over life to frailty differences in old age: comparison of life-course models in a French sample of 2350 old people
Introduction
Socioeconomic factors are important determinants of health status, throughout adulthood and old age [1]. European studies have shown that disadvantaged people die earlier than people in advantageous socioeconomic circumstances (high level of education or income) and that groups of lower socioeconomic status are more likely to report poorer health [2]. Socioeconomic inequalities can be enhanced in old age. Indeed, aging is often associated with a loss of income because of retirement or widowhood, and old people are more likely to face financial difficulties compared with their midlife counterparts. Data from two English cohorts have actually highlighted social gradients in both walking speed [3], [4] and incidence of functional impairment [5].
A growing body of evidence suggests that health inequalities in later life cannot be fully understood without taking into account earlier life experiences. For instance, data from the Wisconsin Longitudinal Study showed that exercise in later life is influenced by socioeconomic status at the age of 18 years, an association partly mediated by socioeconomic resources and health in midlife [6]. In a Swedish cohort of men and women born in the period of 1915 to 1929, Mishra et al. [7] examined the effect of socioeconomic position (SEP) across lifetime on mortality in old age. Findings indicated that SEP at birth, in adulthood, and in later life independently increased mortality risk.
Among health measures in old age, frailty is increasingly used in both clinical and epidemiologic studies. Frailty is a geriatric concept that refers to the increased vulnerability to stressors [8]. This is an age-related predictor of adverse health outcomes and mortality in old age, which is the result of a decrease in physiological reserves of multiple systems [9]. Although the existence of a social gradient in frailty in old age is well documented [10], [11], [12], [13], [14], [15], [16], [17], [18], [19], [20], only a few studies have examined the effect of the period of exposure to social inequalities [19], [21].
In this context, this study aims to investigate the effect of SEP at each life stage on health in old age, measured using a frailty index (FI).
Section snippets
Study design and population
This work is part of a cross-sectional study carried out to characterize health and functional independence among people aged 70 years and older (SIPAF study, French acronym for “Système d’Information sur la Perte d’Autonomie Fonctionnelle de la personne âgée,” meaning “information system for loss of functional autonomy of the elderly”). Subjects were selected at random among participants in a supplementary pension fund, AG2R La Mondiale (Paris, France), with over-representation of strata of
Study population
A total of 2350 people agreed to participate in the study (participation rate: 18.9%). The main reasons for nonparticipation were the lack of interest in the study (28.3% of the nonparticipants), followed by a state of frailty (10.8%) and the refusal of a close relative (7.3%). Participation was better in low-populated areas and in departments where the population is aging or with a lower standard of living. Besides, participants were on average 2.3 years younger than nonparticipants (P
Discussion
In addition to a number of health variables, this study assessed different carriers of social inequalities in health, namely childhood deprivation, low level of education, low occupational class, and financial insecurity in old age. By using life-course models, this framework offered the possibility to test hypotheses with regard to the specific effect of each period of social disadvantage, as well as hypotheses with regard to their combined effects. Finally, results indicated that each period
Acknowledgment
This work was supported by AG2R La Mondiale (staffing, data management) and Université Versailles St-Quentin-en-Yvelines (data analyses). In addition to our sources of funding, we thank Jean-Pierre Audran for his involvement in setting up the study, Isabelle Remy for her logistical support, and Frédéric Simoes Da Gama for his contribution to data management.
References (37)
- et al.
Frailty in elderly people
Lancet
(2013) - et al.
Explaining the association between educational level and frailty in older adults: results from a 13-year longitudinal study in the Netherlands
Ann Epidemiol
(2014) - et al.
Prevalence and factors associated with frailty in an older population from the city of Rio de Janeiro, Brazil: the FIBRA-RJ Study
Clinics
(2013) - et al.
Frailty and migration in middle-aged and older Europeans
Arch Gerontol Geriatr
(2014) - et al.
Development and validation of a geriatric depression screening scale: a preliminary report
J Psychiatr Res
(1982) - et al.
“Mini-mental state”. A practical method for grading the cognitive state of patients for the clinician
J Psychiatr Res
(1975) - et al.
Association of frailty with survival: a systematic literature review
Ageing Res Rev
(2013) - et al.
Frailty, financial resources and subjective well-being in later life
Arch Gerontol Geriatr
(2014) - et al.
SES differentials in health by age and alternative indicators of SES
J Aging Health
(1996) - et al.
Socioeconomic inequalities in health in 22 European countries
New Engl J Med
(2008)
Social inequality in walking speed in early old age in the Whitehall II study
J Gerontol A Biol Sci Med Sci
Relationship between wealth and age trajectories of walking speed among older adults: evidence from the English Longitudinal Study of Ageing
J Gerontol A Biol Sci Med Sci
Inequalities in health at older ages: a longitudinal investigation of the onset of illness and survival effects in England
Age Ageing
Early-life socioeconomic status and physical activity in later life: evidence from structural equation models
J Aging Health
Socio-economic position over the life course and all-cause, and circulatory diseases mortality at age 50-87 years: results from a Swedish birth cohort
Eur J Epidemiol
Aging, frailty and age-related diseases
Biogerontology
Social determinants of frailty
Gerontology
Neighborhood deprivation, individual socioeconomic status, and frailty in older adults
J Am Geriatr Soc
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2023, Archives of Gerontology and GeriatricsCitation Excerpt :Similar to Western societies, education, occupation, and income are the leading determinants of SEP in Taiwan. A large body of literature highlights the associations between SEP and frailty among elderly populations, with many studies using accumulation risk models and sensitive or critical period hypotheses of life-course SEP to investigate frailty (Alvarado et al., 2008; Herr et al., 2015; van der Linden et al., 2020). However, how SEP mobility during the life course relates to frailty among elderly people in Taiwan remains unclear.
Multi-group frailty trajectories among older Koreans: Results from the Korean Longitudinal Study of Aging
2022, Archives of Gerontology and GeriatricsCitation Excerpt :Relationships between these factors and frailty remain inconclusive in the literature. Women and those with low socioeconomic status were associated with increased frailty risk in cross-sectional studies (Collard et al., 2012; Herr et al., 2015; Santos-Eggimann et al., 2009), while sex and marital status were not related with frailty trajectories (Peek et al., 2012). A previous study also suggests that non-married older adults may show a slower frailty progression (Hoogendijk et al., 2018).
Midlife contributors to socioeconomic differences in frailty during later life: a prospective cohort study
2018, The Lancet Public HealthThe association between bouts of moderate to vigorous physical activity and patterns of sedentary behavior with frailty
2018, Experimental GerontologyCitation Excerpt :An age, sex, and accelerometer wear time adjusted model was initially completed for each exposure variable individually, followed by a fully adjusted model. We included the following variables in the fully adjusted models based on previous literature which have shown a relationship with the FI (example references are provided): age (Kehler et al., 2017; Rockwood et al., 2011), sex (Gordon et al., 2017), ethnicity (Shamliyan et al., 2013; Espinoza and Hazuda, 2008), education (Rockwood et al., 2011), income (Hubbard et al., 2014), marital status (Rockwood et al., 2011), smoking status (Hubbard et al., 2009), alcohol consumption (Herr et al., 2015), body mass index (Hubbard et al., 2010), and total sedentary time (Blodgett et al., 2015). Accelerometer wear time was also added to the fully adjusted model to control for differences in wear time across study participants.