A researcher is conducting a study on breast cancer risk in a particular community. In a population of 10,000 individuals, 300 new cases of a breast cancer are diagnosed over the course of one year.
Which of the following statements is correct regarding the incidence of breast cancer in the community being studied?
The incidence rate is calculated by dividing the number of new cases by the population at risk and expressing it as a rate per unit of the population. In this scenario, 300 cases in a population of 10,000 individuals yields an incidence rate of 30 per 1,000 individuals per year.
Answer choice A: The breast cancer incidence rate is 3 per 1,000 individuals per year, is incorrect. The calculation of incidence rate involves dividing the number of new cases by the population at risk. Here, 300 cases in a population of 10,000 equates to an incidence rate of 30 per 1,000 individuals per year.
Answer choice C: The breast cancer incidence rate is 0.3 per 100 individuals per year, is incorrect. This calculation would yield an incidence rate that is lower than the actual value, as it implies a smaller portion of the population is affected.
Answer choice D: The breast cancer incidence rate is 0.03 per 100 individuals per year, is incorrect. This calculation would yield a much lower incidence rate than the actual value, as it suggests a smaller proportion of the population is affected.
Answer choice E: The breast cancer incidence rate is 0.03 per 1,000 individuals per year, is incorrect. This calculation would yield a much lower incidence rate than the actual value, as it suggests a smaller proportion of the population is affected.
Key Learning Point
Incidence rate represents the rate of occurrence of new cases of a disease within a specified population over a defined period. It is calculated by dividing the number of new cases by the population at risk and expressing it as a rate per unit of the population and time, such as per 1,000 individuals per year. In this scenario, the disease's incidence rate is 30 per 1,000 individuals per year, indicating the rate of new cases within the population over one year.
