Quality of life, health and physiological status and change at older ages.

The relationship between self-reported health status and quality of life at older ages is well established. The present paper investigates this relationship further, using objective measures of health and their change over time in the English Longitudinal Study of Ageing, where positive quality of life at older ages was measured as CASP-19. Cross-sectionally, lung function and obesity, but not blood pressure, were associated with quality of life; these relationships in path analysis were transmitted primarily via functional limitation and more modestly, and only for lung function, via clinical depression. Longitudinally, the results suggest a stable and long-term influence on quality of life of lung function and, among women, body mass index, to which the influence of change may be cumulative; longer follow-up is required to clarify these processes. Overall, the results show that the relationship between health and quality of life is independent of potential psychological confounders, that functional limitation is the key dimension of health in its relationship with quality of life and that clinical depression may be an important mediator between functional limitation and quality of life.