Convert cumulative incidence rate to age

convert_cir_to_age computes the age from a person's cumulative incidence rate.

Usage

convert_cir_to_age(cir, pop_prev = 0.1, mid_point = 60, slope = 1/8)

Arguments

cir

A positive number representing the individual's cumulative incidence rate.

pop_prev

A positive number representing the overall population prevalence. Must be at most 1 and must be larger than cir. Defaults to 0.1.

mid_point

A positive number representing the mid point logistic function. Defaults to 60.

slope

A number holding the rate of increase. Defaults to 1/8.

Value

If cir and mid_point are positive numbers, if pop_prev is a positive number between 0 and 1 and if slope is a valid number, then convert_cir_to_age returns a number, which is equal to the current age.

Details

Given a person's cumulative incidence rate (cir), convert_cir_to_age can be used to compute the corresponding age, which is given by $$mid\_ point - \log(pop\_ prev/cir - 1) * 1/slope$$

Examples

curve(sapply(cir, convert_cir_to_age), from = 0.001, to = 0.099, xname = "cir")