Translations:Advanced Field Epi:Manual 1 - Disease Investigation/19/en

If animals are lost to follow-up during the period of interest, then the denominator should be adjusted to take this into account. The same principle applies if any new animals enter the population at risk during the time period. There are several commonly used methods for adjusting the count of population at risk in open populations. The two approaches most commonly used for cumulative incidence estimation are described below: