Relationships of disability with age among adults aged 50 to 85: evidence from the United States, England and continental europe

Abstract

Objectives: To extend existing research on the US health disadvantage relative to Europe by studying the relationships of disability with age from midlife to old age in the US and four European regions (England/Northern and Western Europe/Southern Europe/Eastern Europe) including their wealth-related differences, using a flexible statistical approach to model the age-functions.

Methods: We used data from three studies on aging, with nationally representative samples of adults aged 50 to 85 from 15 countries (N = 48225): the US-American Health and Retirement Study (HRS), the English Longitudinal Study of Ageing (ELSA) and the Survey of Health, Ageing and Retirement in Europe (SHARE). Outcomes were mobility limitations and limitations in instrumental activities of daily living. We applied fractional polynomials of age to determine best fitting functional forms for age on disability in each region, while controlling for socio-demographic characteristics and important risk factors (hypertension, diabetes, obesity, smoking, physical inactivity).

Results: Findings showed high levels of disability in the US with small age-related changes between 50 and 85. Levels of disability were generally lower in Eastern Europe, followed by England and Southern Europe and lowest in Northern and Western Europe. In these latter countries age-related increases of disability, though, were steeper than in the US, especially in Eastern and Southern Europe. For all countries and at all ages, disability levels were higher among adults with low wealth compared to those with high wealth, with largest wealth-related differences among those in early old age in the USA.

Conclusions: This paper illustrates considerable variations of disability and its relationship with age. It supports the hypothesis that less developed social policies and more pronounced socioeconomic inequalities are related to higher levels of disability and an earlier onset of disability.

Figure 1. Mean numbers of disability (unadjusted) across countries.

Note. (Sweden, SE; Denmark, DK; Germany, DE; Netherlands, NL; Belgium, BE; France, FR, Switzerland, CH; Austria, AT; Italy, IT; Spain, ES; Greece, GR; Poland, PO; Czech Republic, CZ; England, EN; United States, US).

Figure 2. Predicted number of disability limitations by age (adjusted).

Note. All models are adjusted for sex, education, wealth, retirement status, partnership, hypertension, diabetes, obesity, smoking, physical inactivity and country (in case of SHARE). “SHARE north/west” includes Sweden, Denmark, Germany, Austria, Netherlands, Belgium, France and Switzerland; “SHARE south” includes Italy, Spain and Greece, “SHARE east” includes Poland and Czech Republic.

Figure 3. Predicted number of mobility limitations by age and wealth (adjusted).

Note. All models are adjusted for sex, education, retirement status, partnership, hypertension, diabetes, obesity, smoking, physical inactivity and country (in case of SHARE). “SHARE north/west” includes Sweden, Denmark, Germany, Austria, Netherlands, Belgium, France and Switzerland; “SHARE south” includes Italy, Spain and Greece, “SHARE east” includes Poland and Czech Republic.

Figure 4. Predicted number of IADL limitations by age and wealth (adjusted).

Note. All models are adjusted for sex, education, retirement status, partnership, hypertension, diabetes, obesity, smoking, physical inactivity and country (in case of SHARE). “SHARE north/west” includes Sweden, Denmark, Germany, Austria, Netherlands, Belgium, France and Switzerland; “SHARE south” includes Italy, Spain and Greece, “SHARE east” includes Poland and Czech Republic.