The aim of calculating the "Standardized Mortality Ratio" SMR is to compare mortality in the cohort with the general population. It is investigated whether the incidence or mortality in the cohort differs from that in the general population. It is calculated how many deaths would be expected in the cohort if the incidence or mortality rate in the cohort were the same as in the general population. To calculate the SMR, the observed deaths from the cohort are divided by the expected deaths.