How do you calculate standardized mortality ratio?

The standardized mortality ratio (SMR) is calculated by dividing the observed number of deaths in a study population by the expected number of deaths based on age-specific mortality rates from a reference population. The formula is: SMR = (Observed Deaths / Expected Deaths) × 100. An SMR of 100 indicates that the mortality rate in the study population is equal to that of the reference population, while values above or below 100 indicate higher or lower mortality, respectively.