elinaikakäyriä

Elinaikakäyrä, often translated as life expectancy curve or survival curve, is a graphical representation used in various fields to illustrate the expected lifespan of a population or a group of individuals. These curves are fundamental tools in demography, epidemiology, medicine, and even in the study of engineered systems. They typically plot the proportion of a population that survives at different ages.

The horizontal axis of an elinaikakäyrä represents age, while the vertical axis shows the proportion of survivors, usually expressed as a percentage or a fraction. The shape of the curve provides insights into mortality patterns. A steep decline in the curve at younger ages indicates high infant or child mortality, while a curve that remains high for a long time before dropping sharply suggests a population with good longevity and a concentration of deaths in older age groups.

There are different types of elinaikäkäyrät. Type I curves show most deaths occurring at older ages, typical of developed countries with good healthcare. Type II curves represent a constant probability of death throughout the lifespan, like in some animal populations or certain diseases. Type III curves show high mortality in early life, with a lower death rate for those who survive infancy, common in many developing nations or historical populations. Understanding these curves is crucial for public health planning, resource allocation, and assessing the impact of interventions.