Elinaikakäyrien

Elinaikakäyrät, sometimes referred to as survival curves or life expectancy curves, are graphical representations used in various fields to illustrate the probability of survival over time for a specific population or group. These curves are most commonly encountered in statistics, medicine, and actuarial science.

The horizontal axis of an elinaikakäyrä typically represents time, which could be measured in days, months, years, or even larger intervals depending on the context. The vertical axis usually depicts the proportion of the population that has survived up to that point in time, often expressed as a percentage or a decimal between 0 and 1. A value of 1 indicates 100% survival, while a value of 0 signifies that no individuals from the initial group remain.

The shape of an elinaikakäyrä provides significant insight. A steep downward slope indicates a high mortality rate within a short period, while a flatter curve suggests lower mortality and a longer expected lifespan. For instance, in medical studies, elinaikakäyrät are used to compare the effectiveness of different treatments by showing how long patients receiving each treatment survive. In reliability engineering, they can illustrate the lifespan of manufactured products. Actuaries use them to estimate the remaining life expectancy of individuals for insurance purposes. The data used to construct these curves is often derived from longitudinal studies or historical records.