trtObserve {simstudy}

Observed exposure or treatment

Description

Observed exposure or treatment

Usage

trtObserve(dt, formulas, logit.link = FALSE, grpName = "trtGrp")

Arguments

dt

data table

formulas

collection of formulas that determine probabilities

logit.link

indicator that specifies link. If TRUE, then logit link is used. If FALSE, the identity link is used.

grpName

character string representing name of treatment/exposure group variable

Value

An integer (group) ranging from 1 to length of the probability vector

See Also

trtAssign

Examples

def <- defData(varname = "male", dist = "binary", formula = .5, id = "cid")
def <- defData(def, varname = "over65", dist = "binary", formula = "-1.7 + .8*male", link = "logit")
def <- defData(def, varname = "baseDBP", dist = "normal", formula = 70, variance = 40)

dtstudy <- genData(1000, def)
dtstudy

formula1 <- c("-2 + 2*male - .5*over65", "-1 + 2*male + .5*over65")
dtObs <- trtObserve(dtstudy, formulas = formula1, logit.link = TRUE, grpName = "exposure")
dtObs

# Check actual distributions

dtObs[, .(pctMale = round(mean(male), 2)), keyby = exposure]
dtObs[, .(pctMale = round(mean(over65), 2)), keyby = exposure]

dtSum <- dtObs[, .N, keyby = .(male, over65, exposure)]
dtSum[, grpPct := round(N / sum(N), 2), keyby = .(male, over65)]
dtSum