Certified Tumor Registrar (CTR) Practice Exam

To calculate the crude incidence rate for colorectal cancer in Buncombe County, the numerator represents the number of newly diagnosed cases within a specific time frame, while the denominator represents the total population at risk during the same period.

In this scenario, the numerator is the number of newly diagnosed cases of colorectal cancer, which is 120 for the year 2016. The denominator consists of the total population of Buncombe County in 2016, which is given as approximately 229,000.

Therefore, the calculation for the crude incidence rate is made by dividing the numerator (120 new cases) by the denominator (229,000 total population), yielding a crude incidence rate that reflects the number of new colorectal cancer cases per population unit.

The choice of 120/229,000 accurately establishes the proper rate calculation, as it uses the actual number of cases and population size relevant to the specified year and locale. The other options either employ different numbers or misrepresent the total population, thus indicating why they do not represent the crude incidence rate correctly.