Better all the time? Trends in health and longevity among older adults in Sweden

Abstract

Background: The health status of the aging population has become one of the major public health concerns today, as the number of older people increases in both absolute and relative terms and life expectancy continues to increase. The increases in life expectancy observed today is mainly the result of improved survival in old age, and as old age is a major risk factor for disease and disability, a major question of concern is to what extent increasing life expectancy comes with years with or without disability.

Aim: The overarching aim of this thesis is to assess whether the increasing old age life expectancy in Sweden has been accompanied by years with or without disability, and to what extent the development differs by gender and education. In addition, the ages and causes of death that drive the increase in life expectancy are investigated. Finally, the burden of disability at exceptional old age is explored in countries with different mortality selection.

Data: The data sources used in this thesis come from Statistics Sweden (SCB), The Swedish Cause of Death Register, the Swedish Panel Study of Living Conditions of the Oldest Old (SWEOLD), The Survey of Health, Ageing and Retirement in Europe (SHARE), and The 5-Country Oldest Old Project (5-COOP).

Study 1: Remaining life expectancy free of severe-disability, mild disability, and mobility limitations at age 77 were estimated at several time points between 1992 and 2011. This was done by combining national mortality statistics from SCB with health data from SWEOLD and SHARE. Results are heterogeneous, but in general years without disability increased more than years with disability. A more favorable development was observed among women and the gender difference in disability-free life expectancy decreased over time. Study 2: The impact of age- and cause-specific mortality on the increase in life expectancy and the decrease in the gender gap in life expectancy between 1997 and 2014 was assessed by using data from the Swedish Cause of Death Registry. Results showed that decreasing mortality from ischemic heart disease in ages 65 and older explained most of the increase in overall life expectancy, and the convergence of the gender gap. On the other hand, certain causes of death had a diminishing impact on life expectancy, most prominently Alzheimer’s disease and unspecified dementia in the age group 85 and above. Study 3: Disability-free life expectancy at age 77 was estimated between 2002 and 2014 by educational attainment. Mortality statistics from SCB by education were combined with disability estimates by education from SWEOLD. Results show that the increase in disability-free life expectancy was greater than the increase in life expectancy for women with both higher and lower education, and for men with higher education. However, for men with lower education, both years with and without disability increased. Overall, there was a more positive development for those with higher education and the inequalities in disability-free life expectancy increased over time. Study 4: The main aim was to test if centenarians in countries with stronger mortality selection into exceptionally old age have a lower level of disability than centenarians in countries with a weaker mortality selection. The 5-COOP survey was used, which includes centenarians from five countries: Japan, France, Switzerland, Denmark, and Sweden. Results indicated that the probability of having disability was lower in the countries with a stronger mortality selection (Denmark and Sweden) than in countries with weaker mortality selection (Japan, France, Switzerland). Nevertheless, the highest probabilities of disability were found in Switzerland, which ranked in the middle in terms of mortality selection

Conclusion: There was an overall positive development, where disability-free life expectancy increased more than total life expectancy during the study period, except for men with lower education. Women had greater gains in disability-free years and greater reduction in disabled years than men, and consequently the gender difference in disability-free life expectancy decreased over time. However, educational differences increased over time as those with lower education did not have the same favorable development as those with higher education. The major driver of the observed increase in life expectancy was reduced mortality from ischemic heart disease among those aged 65 and older. Among centenarians, however, the burden of health problems is high and appears to be greater in countries with a weaker mortality selection into exceptionally old age.