Compression and plasticity of old-age mortality

Abstract

In this thesis we first studied the start of the epidemiologic transition in rural Ghana and describe the changes in mortality. This is followed by studies on the compression of mortality and morbidity during the transition in Japan and the Netherlands. Finally, we examined the plasticity of mortality at old age. Studying old-age mortality during the epidemiologic transition is of great importance now that an increasing number of people reach old-age. The main findings from this thesis are that overall, when countries shift from a pre- to a post-transitional stage, mortality decreases and an increasing number of people live up to old age. In addition, mortality is compressed to a narrower age interval in which most of the annual deaths occur. This compression of mortality reaches a limit as soon as countries enter the post-transitional era. Furthermore, during the last stage of the epidemiologic transition we have observed that life expectancy without disability is increasing parallel to the increase in life expectancy, indicating a compression of disability. Finally we found that, mortality remains highly plastic up to old age, as indicated by the continuous rise in life expectancy and the shift of the age-at-death distribution towards higher ages.