How to assess case-finding in chronic diseases: Comparison of different indices

Recently, we have proposed a new illness-death model that comprises a state of undiagnosed chronic disease preceding the diagnosed disease. Based on this model, the question arises how case-finding can be assessed in the presence of mortality from all these states. We simulate two scenarios of different performance of case-finding and apply several indices to assess casefinding in both scenarios. One of the prevalence based indices leads to wrong conclusions. Some indices are partly insensitive to distinguish the quality of case-finding. The incidence based indices perform well. If possible, incidence based indices should be preferred.