Work out incidence rate instantly with clear inputs, formula shown and shareable results.
Divides new cases by the person-time at risk to give a true incidence rate, then scales it to the chosen population multiplier.
Incidence rate
Incidence rate = new cases / person-time at risk, expressed per 1,000, 10,000 or 100,000 person-years
Cumulative incidence divides cases by the number of people at the start; an incidence rate uses person-time and handles varying follow-up.
Only people still at risk. Time after diagnosis, death or loss to follow-up is excluded.