PoD {PoDBAY}

Probability of disease calculation

Description

Function calculates probability of disease (PoD) corresponding to given titers according to a sigmoid PoD curve.

Usage

PoD(titer, pmax, et50, slope, adjustTiters = FALSE, adjustFrom = 0, adjustTo = 0)

Arguments

titer

numeric vector: subject level titers

pmax

numeric: maximum PoD

et50

numeric: titer values corresponding to pmax/2 value, PoD(et50) = pmax/2

slope

numeric: slope of the PoD curve

adjustTiters

boolean: set to TRUE if titer values should be adjusted, for details see PoD function

adjustFrom

numeric: value specifying the detection limit, all values below the detection limit will be adjusted to adjustTo value

adjustTo

numeric: value to which titers below the detection limit will be adjusted

Details

PoD is calculated as:

PoD = p_{max} \frac{ (\frac{et50}{titer})^{\gamma} }{ 1 + (\frac{et50}{titer})^{\gamma}}, \ for \ titers \ > 0

and

PoD = pmax, \ for \ titers \ <= 0

.

Value

vector of PoDs

Examples

data(vaccinated)
data(PoDParams)

PoD(vaccinated$titers, pmax = PoDParams$pmax, et50 = PoDParams$et50, slope = PoDParams$slope)