Question

A sample of 100 healthy men was followed for the development of prostate cancer. After being followed for 5 years, 20 men of the study sample developed prostate cancer. Another 10 men of the sample were followed up for 1 year and then were lost to follow up and we do not have information about their prostate cancer status. The remaining men who never developed the disease were followed for 10 years. Calculate the number of person-years of observation accrued by this population.

Answer 1

Answer: The number of person - year accrued by the population being observed is 1,210person-year.

Step-by-step explanation: Person-year is the calculation of the actual time a participant is at risk in the study,assuming that all participants participated in the study. Because some people will never be infected in a study and some will be infected at a particular point in time. This is why the person per time is necessary in the study. It is the sum of time spent on following up people that has not been affected by the disease in the study.

CALCULATING THE PERSON-YEAR

1) 100 persons are followed for 5years

2) 10 persons are followed for a year and then lost

3) The remaining were followed for 10years. The remaining are sample, after subtracting the 20 infected persons and the 10persons that were lost from the 100 persons, which was the initial sample. That means 70 persons were followed up for 10years.

Therefore;

100persons × 5years = 500 person-year

10persons × 1year = 10 person-year

70persons × 10years = 700person - year.

Therefore the sum of the person-year.

500+10+700 = 1,210 person-year

The number of person - year accrued by the population being observed is 1,210 person-year.