How do you calculate average duration in epidemiology?

In epidemiology, the average duration of an event or condition can be calculated by dividing the total duration of the event or condition by the total number of cases.

For example if you have a disease with a duration of 10 days for the first patient, 20 days for the second patient, 15 days for the third patient, and 5 days for the fourth patient, the average duration would be calculated as:

(10 + 20 + 15 + 5) = 50 days. Hence the average duration of disease in this case is 50/4= 12.5 days.