fitLogistic: Fit logistic regression model

In TrialSimulator: Clinical Trial Simulator

Fit logistic regression model

Description

Fit logistic regression model on an binary endpoint.

Refer to this vignette for more information and examples.

Usage

fitLogistic(formula, placebo, data, alternative, scale, ...)

Arguments

formula	An object of class formula. Must include arm and endpoint in data. Covariates can be adjusted.
placebo	Character. String indicating the placebo in data$arm.
data	Data frame. Usually it is a locked data set.
alternative	a character string specifying the alternative hypothesis, must be one of "greater" or "less", i.e., one-sided test is enforced. No default value. "greater" means superiority of treatment over placebo is established by an odds ratio greater than 1.
scale	character. The type of estimate in the output. Must be one of "coefficient", "log odds ratio", "odds ratio", "risk ratio", or "risk difference". No default value.
...	Subset conditions compatible with dplyr::filter. glm will be fitted on this subset only. This argument can be useful to create a subset of data for analysis when a trial consists of more than two arms. By default, it is not specified, all data will be used to fit the model. More than one condition can be specified in ..., e.g., fitLogistic(remission ~ arm, 'pbo', data, 'greater', 'odds ratio', arm %in% c('pbo', 'low dose'), cfb > 0.5), which is equivalent to: fitLogistic(remission ~ arm, 'pbo', data, 'greater', 'odds ratio', arm %in% c('pbo', 'low dose') & cfb > 0.5). Note that if more than one treatment arm are present in the data after applying filter in ..., models are fitted for placebo verse each of the treatment arms.

Value

a data frame with columns:

arm

name of the treatment arm.

placebo

name of the placebo arm.

estimate

estimate depending on scale.

p

one-sided p-value for log odds ratio (treated vs placebo).

info

sample size used in model with NA being removed.

z

z statistics of log odds ratio (treated vs placebo).

TrialSimulator documentation built on Nov. 5, 2025, 7:22 p.m.