Aging and chronic disease as independent causative factors for death and a programmed onset for chronic disease.

To explore the relationship between occurrence of chronic diseases and the aging process, the role of age in death from disease was assessed by receiver operating curve (ROC) analysis, to quantify differences in the age compositions between death and survival groups using data for various diseases and from regions of different socioeconomic status in China. Results showed that the contribution of age to different diseases was varied. Increase in life expectancy was associated with relatively old age at the time of death for five of seven diseases. For cancer and diseases of the circulatory system, increase in life expectancy was associated with relatively younger age at the time of death. These findings indicate that chronic diseases may occur independently of aging and may have a programmed onset pattern.