Mortality among the elderly in the U.S., 1956-1987: demonstration of the upper boundary to Gompertzian mortality.

Mortality in the United States among individuals aged 85 years and older between the years 1956 and 1987 was analyzed using a cumulative summation technique. This analysis demonstrates that general mortality conforms to Gompertzian dynamics through age 96 years for both men and women. Of the 33 320 985 deaths in men in the U.S. between 1956 and 1987, only 123,643 (0.37%) occurred in men aged 97 years and older. Of the corresponding 26,946,599 deaths in women, only 327,291 (1.21%) occurred in women aged 97 years and older. These results suggest that the competitive and deterministic features of the Gompertzian model of human aging and mortality remain valid through age 96 years and cover the vast majority of human mortality.