Area compatibility factor

Overview
In survival analysis, the area compatibility factor, F, is used in indirect standardisation of population mortality rates.


 * $$F = \frac{\sum_x {}^sE_{x,t}^c {}^sm_{x,t}}{\sum_x {}^sE_{x,t}^c} \left/

\frac{\sum_xE_{x,t}^c {}^sm_{x,t}}{\sum_x E_{x,t}^c}\right.$$

where:


 * $${}^sE_{x,t}^c$$ is the standardised central exposed to risk from age x to x + t for the standard population,


 * $$E_{x,t}^c$$ is the central exposed to risk from age x to x + t for the population under study and


 * $${}^sm_{x,t}$$ is the mortality rate in the standard population for ages x to x + t.

F is then multiplied by the crude mortality rate to arrive at the indirectly standardised mortality rate.