Question

In a mass screening of 5000 women, 25 of these were found to have breast cancer. During the next 5 years 10 more of the examined women developed breast cancer. Calculate the point prevalence of breast cancer in this population. What is the risk of developing breast cancer among these women?

Answer 1

Point prevalence is the number of persons ill on the date divided by the population on that date.

So here No of ill people = 25

Total number of people =5000

Point prevalence= 25/5000 = 0.005 * 100 = 0.5%

Point of prevalence after 10 years. = 35/5000 =0.007*100 = 0.7%

Incidence risk is the total number of new cases divided by the population at risk at the beginning of the observation period.

Total number of new cases = 35

Total population at the beginning = 5000

No of years = 5 years

35/5000 * 5 = 0.007* 5 =0.035 breast cancer cases per year