Centenarians Today: New Insights on Selection from the 5-COOP Study

Area of Science:

• Demography
• Gerontology
• Public Health

Background:

• The population of individuals aged 90 and above has significantly increased globally.
• The growth rate of the oldest old population varies considerably across different countries.
• Understanding mortality patterns in this demographic is crucial for public health planning.

Purpose of the Study:

• To quantify and compare mortality selection levels among nonagenarians and centenarians in five low-mortality nations.
• To identify country-specific differences in survival probabilities for the oldest old.
• To lay the groundwork for future research on health status trade-offs within the 5-Country Oldest Old Project (5-COOP).

Main Methods:

• Utilized data from the Human Mortality Database for Denmark, France, Japan, Switzerland, and Sweden.
• Incorporated specific data for Japan's centenarian population.
• Analyzed demographic data to assess mortality selection differentials.

Main Results:

• Identified three distinct levels of mortality selection across the studied countries.
• Observed a milder mortality selection in Japan.
• Found stronger mortality selection in Denmark and Sweden, with intermediate levels in France and Switzerland.

Conclusions:

• Significant variations in mortality selection exist among the oldest old in developed countries.
• These differences provide a basis for investigating the relationship between mortality selection and functional health outcomes.
• The findings support the ongoing research within the 5-Country Oldest Old Project (5-COOP).