Health trends of the ageing population in Sweden : association of mortality reductions with morbidity and quality of life improvements

Sammanfattning: Since the beginning of the 19th century, and particularly after the 1950s, life expectancy of the elderly in all developed countries, including Sweden, has increased substantially, posing the question whether the health of the ageing population has also been improving over time. The aim of this PhD thesis was to investigate morbidity occurrence among the elderly in Sweden, attempting to answer the question of whether their overall health and quality of life has been improving over time in parallel with mortality reductions. Analysis was conducted using data from the national registers (studies I to III), combined in study IV with data from the Stockholm Public Health Cohort. In Studies I and II, the time from age 60 until the first and subsequent morbidity, measured using hospital admissions of any cause as a proxy, was estimated for the years between 1995 and 2010; it was then associated with the change over time in the remaining life expectancy at the age of 60. Postponement to higher ages for both mortality and first and subsequent morbidity was observed, for both men and women, and for most ages. In Study III, morbidity from hip fractures, which is a prominent disease among the elderly in Sweden, has been estimated. In addition, survival after the disease and the lifetime risk of the disease, have been measured. Incidence of hip fractures decreased over time for both men and women up to the age of 94, while no real improvements have been observed for survival after the first hip fracture or for the lifetime risk. In addition to administrative information from registers about hospital admissions, which does not necessarily capture individuals’ full disease panorama, the health-related quality of life (HRQoL) of individuals was used in study IV to determine whether a hospitalization could indicate the onset of a period of life for the elderly lived with compromised health. Results revealed that only one hospitalization had no long-term consequences on the quality of life; multiple ones, however, did lead to severe morbidity and quality of life reductions. To conclude, morbidity among the elderly in Sweden seems to have been postponed to higher ages over the years, in parallel with survival improvements observed during the same period. However, individuals have not become more fragile, since the occurrence of subsequent morbidity events has also been prolonged. Lifestyle changes and the increasingly beneficial role preventive medicine plays for individuals’ health, which could be leading to the reduction of the incidence of prominent diseases for the elderly such as cardiovascular conditions and hip fractures, could explain such health improvements over time.