Crude Rates
Crude rates are calculated by dividing the number of events; i.e., births or deaths, by the population in which the events (i.e., births to women of child bearing age, or deaths due to a certain cause) are occurring in a specified period of time such as one year.
Age-Adjusted Death Rates
Age-adjusted death rates are calculated to allow comparisons of death rates between two populations at the same time or the same population at different times. The age-adjustment process removes differences in the age composition of two or more populations to allow comparisons between these populations independent of their age structure.
Incidence Rates
Incidence is a way of measuring the risk of a disease in a population. An incidence rate is calculated by dividing the number of new cases of a disease by the population in which the disease is occurring in a defined period of time (e.g., one year) and multiplying this number by 100,000.
