An age-standardised rate (ASR) is a summary measure of the rate that a population would have if it had a standard age structure. Standardization is necessary when comparing several populations that differ with respect to age because age has a powerful influence on the risk of dying from cancer. The ASR is a weighted mean of the age-specific rates; the weights are taken from population distribution of the standard population. The most frequently used standard population is the World Standard Population. The calculated mortality rate is then called age-standardised mortality rate (world). The world standard population used within the application is as proposed by Segi (1960) and modified by Doll and al. (1966). The ASR is also expressed per 100,000.
Source: WHO