Illustration of Normally Distributed Progression Over Time In An Incident Cohort. In this example, an identical average annual rate (0.078) and risk (7.5%) of progression over a 25 year period has been modeled as in figure 3. However, through a transformation, the absolute risk of progression over time has now been rendered normally distributed (with standard deviation of 6) with the largest proportion of individuals now progressing near year 13 rather than year 1.
Insinga et al. BMC Infectious Diseases 2009 9:119 doi:10.1186/1471-2334-9-119