User:Bluerasberry/person year

A person year, (also called patient year) is a unit of measurement for describing incidence.

The unit is equivalent to the sum of the number of years the individuals in a cohort are living in the observed condition. During the years when researchers observe the people in the cohort, they count the number of times the people experience a medical issue. At the end the researchers report their findings of observing a certain number of incidents per person years.

The unit is widely used but has some shortcomings. There are alternative measures which also have their own shortcomings.