alderstandardisering

Alderstandardisering is a statistical technique used to adjust age-specific rates for differences in age structure when comparing populations or making comparisons over time. It is particularly useful when the age distribution of the populations being compared is significantly different, as this can distort direct comparisons of rates. The core idea is to remove the effect of age composition so that the observed differences in rates can be attributed to factors other than age.

The process typically involves selecting a standard population, which can be an actual population with a stable age structure or a hypothetical distribution. Age-specific rates from the population(s) of interest are then applied to the age structure of this standard population. This yields a set of age-standardized rates, which are hypothetical rates that would be observed if the population of interest had the age structure of the standard population. By using the same standard population for all comparisons, the influence of age is neutralized, allowing for a more accurate assessment of differences or changes in the phenomenon being studied, such as disease incidence, mortality, or fertility. Two common methods for age standardization are direct standardization and indirect standardization, each with its own application depending on the available data.