What is the standard mortality ratio used for?

The standard mortality ratio (SMR) is a measure used to compare the observed number of deaths in a specific population to the number of deaths that would be expected based on a standard population. It is commonly used in epidemiology and public health to assess the mortality risk associated with specific factors, such as diseases, treatments, or demographic characteristics. An SMR greater than 1 indicates higher mortality than expected, while an SMR less than 1 suggests lower mortality. This metric helps identify health disparities and the effectiveness of interventions.