Population aging patterns: the expansion of mortality.

Area of Science:

• Demography
• Gerontology
• Public Health

Background:

• The concept of mortality compression posits that lifespan increases lead to a tighter clustering of deaths around the maximum age.
• Previous research suggested a trend towards compressing mortality at older ages.

Purpose of the Study:

• To examine mortality patterns between 1962 and 1984 using the mortality compression hypothesis.
• To analyze changes in the age at death and the force of mortality across different population percentiles.

Main Methods:

• Utilized national vital statistics records to analyze age at death distributions.
• Employed data from the Social Security Administration and U.S. Census Bureau to calculate the force of mortality.
• Examined the coefficient of variation for mean age at death to assess variability.

Main Results:

• The mean age at death increased across all population percentiles, including the oldest groups.
• A relative increase in the variability of age at death was observed among the oldest old (over 85).
• The force of mortality for those over 85 decreased, mirroring patterns seen in younger age groups.

Conclusions:

• Observed mortality patterns suggest an "expansion" rather than "compression" of mortality at the oldest ages.
• The data did not support a hypothetical model of normal distributions with decreasing standard deviation.
• Further research with enhanced data on the oldest old is needed to refine understanding of mortality patterns.