Makeham's addition to the Gompertz law re-evaluated

Area of Science:

• Demography
• Biostatistics
• Epidemiology

Background:

• The Gompertz law models human mortality but includes aging and external factors.
• Distinguishing between intrinsic (aging) and extrinsic (external) mortality is crucial for accurate analysis.
• Current models may conflate these factors, leading to biased interpretations.

Purpose of the Study:

• To propose the Makeham parameter as a distinct measure of extrinsic mortality.
• To isolate the impact of external factors on mortality rates by removing the effects of aging.
• To refine mortality modeling by separating intrinsic and extrinsic influences.

Main Methods:

• Utilizing the Gompertz law of human mortality.
• Introducing the Makeham parameter as a constant mortality rate independent of aging.
• Analyzing mortality data to differentiate between aging-dependent and aging-independent components.

Main Results:

• The Makeham parameter effectively measures mortality due to extrinsic causes.
• A small intrinsic mortality component, linked to cellular function, influences the initial Gompertz rate.
• Removing extrinsic mortality's impact from Gompertz parameters prevents biased conclusions.

Conclusions:

• The Makeham parameter provides a valuable tool for assessing extrinsic mortality.
• Separating intrinsic and extrinsic mortality factors enhances the precision of demographic and epidemiological studies.
• This approach allows for a clearer understanding of mortality dynamics and the factors driving them.