Human mortality at extreme age

Area of Science:

• Demography
• Biostatistics
• Gerontology

Background:

• Understanding mortality patterns in extreme old age is crucial for demographic projections and healthcare planning.
• Semi-supercentenarians (aged 105+) represent a unique population for studying the limits of human longevity.
• Previous studies have yielded mixed results regarding the existence of an upper bound to human lifespan.

Purpose of the Study:

• To analyze mortality patterns in Italian and French semi-supercentenarians using advanced statistical methods.
• To investigate whether a constant force of mortality exists beyond age 108.
• To determine if there are differences in mortality between countries, cohorts, and sexes at extreme ages.

Main Methods:

• Application of extreme value statistics to model mortality.
• Utilisation of survival analysis and computer-intensive methods.
• Analysis of mortality data from Italian and French semi-supercentenarian populations, accounting for sampling frame effects.

Main Results:

• Extreme-value modeling indicates a constant force of mortality beyond 108 years.
• No significant differences in mortality were observed between Italian and French populations or cohorts after age 108.
• Power calculations suggest an upper lifespan bound is unlikely to be below 130 years.
• No sex differences in survival were found after age 108 in Italian data and the International Database on Longevity, but French men showed lower survival.

Conclusions:

• The data supports a constant force of mortality beyond 108 years, implying no discernible upper limit to human lifespan.
• Findings are consistent with Gompertz models and previous longevity research.
• The physical upper bound for human lifespan, if it exists, is likely beyond current empirical observation.