Life-course influences on mortality at older ages: Evidence from the Oslo Mortality Study

Abstract

Several studies have investigated the cumulative influence of disadvantage acting from early to adult life. And they suggest that risk of death increases in a cumulative fashion. Few studies have investigated the life-course influences on social inequality in mortality in early old age. In this study we wanted to follow a cohort through their adult working age into retirement and investigate pathways that may give increased risk of mortality. A cohort of all inhabitants in the age range 68–72 who lived in the municipality of Oslo on 1st January 1990 was selected. Data were obtained by linking censuses from 1960, 1970 and 1980 with tax registry in 1990 and death registry 1990–1998. Independent variables were occupational class in 1960, 1970 and 1980 and household income in 1990. Occupational class was coded as manual and non-manual and household income as above or below median household income. A cumulative model was developed by adding times of disadvantage. Then a pathway model was developed which investigated the specific trajectories individuals followed. Most of the increased risk of death was explained by individuals’ social conditions in 1990. In the cumulative model, there was no clear gradient in the groups between the bottom and top categories. This suggests that the cumulative model is not important in the high mortality age and that the relative importance of a cumulative effect varies by stages of the life course.