Relation between trends in late middle age mortality and trends in old age mortality--is there evidence for mortality selection?

STUDY OBJECTIVE: To test whether mortality selection was a dominant factor in determining trends in old age mortality, by empirically studying the existence of a negative correlation between trends in late middle age mortality and trends in old age mortality among the same cohorts. DESIGN AND METHODS: A cohort approach was applied to period data on total and cause specific mortality for Denmark, England and Wales, Finland, France, the Netherlands, Norway, and Sweden, in 1950-1999. The study described and correlated mortality trends for five year centralised cohorts from 1895 to 1910 at ages 55-69, with the trends for the same cohorts at ages 80-89. The research distinguished between circulatory diseases, cancers, and diseases specifically related to old age. MAIN RESULTS: All cause mortality changes at ages 80-89 were strongly positively correlated with all cause mortality changes at ages 55-69, especially among men, and in all countries. Virtually the same correlations were seen between all cause mortality changes at ages 80-89 and changes in circulatory disease mortality at ages 55-69. Trends in mortality at ages 80-89 from infectious diseases, pneumonia, diabetes mellitus, symptoms, or external causes showed no clear negative correlations with all cause mortality trends at ages 55-69. CONCLUSIONS: The consistently positive correlations seen in this study suggest that trends in old age mortality in north western Europe in the late 20th century were determined predominantly by the prolonged effects of exposures carried throughout life, and not by mortality selection.