Figure 1From: Age of onset in chronic diseases: new method and application to dementia in Germany IPM model. Simple model of a chronic disease with three states. People in the state Normal are healthy with respect to the considered disease. In the state Disease they suffer from the disease. The transition rates depend on the calendar time t, on the age a, and in the case of mortality m 1 of the diseased people, on the disease’s duration d.Back to article page