The rate of a disease can be used to calculate the transition probability, or the probability of transition from being without to having the disorder.
Parameter: rate of a disorder in number per 100 patients per year
number per 100 per year =
= 100 * (number of people affected in 1 year) / (total population)
transition probability per year =
= 1 - EXP((-1) * (rate per 100 per year) / 100)
transition probability per month =
= 1 - EXP((-1) * (rate per 100 per year) / (12* 100))