Dynamics of health changes in the oldest old: new perspectives and evidence.

Improvement in survival at advanced ages suggests that important changes in health and the natural history of disease processes may be occurring concurrently. a general model based upon cohort and life-course perspectives describes the changing relation of morbidity, disability, and mortality over time. Variability across different social and economic conditions is examined among institutionalized and non-institutionalized elderly, and between the United States and Japan. Future policy must take account of the qualitative, as well as the quantitative, changes in aging.