Incidence rates, or the rates of new cases of a disease, are often shown as the rate per either 100,000 population or per 10,000 population, and provide valuable additional insight to the number of new cases of the disease.
In scenarios when comparing the incidence of a disease across different localities that have varying different sizes in population, looking at the incidence rate of that disease per 10,000 or per 100,000 population helps to show a more complete picture than would only looking at the number of new cases alone.
Examples are given in the quick, 3 minute video below to further illustrate this point.
In conclusion, showing the incidence rate per 10,000 or per 100,000 population provides additional valuable insight in addition to showing the number of new cases of the disease. This is especially true when comparing the incidence rate of the disease across different localities that have varying sizes in populations. In addition, looking at the incidence rate per population is essential when comparing that rate to a state or national average for that disease or comparing it to a benchmark or goal that is in the format of an incidence rate per population.