add1.logistf

Compute all the single terms in the scope argument that can be added to or dropped
from the model, fit those models and compute a table of the changes in fit.

Fit a logistic regression model using Firth's bias reduction method, equivalent to penalization of the log-likelihood by the Jeffreys
prior. Confidence intervals for regression coefficients can be computed by penalized profile likelihood. Firth's method was proposed as ideal
solution to the problem of separation in logistic regression, see Heinze and Schemper (2002) <doi:10.1002/sim.1047>. If needed, the bias reduction can be turned off such that ordinary
maximum likelihood logistic regression is obtained. Two new modifications of Firth's method, FLIC and FLAC, lead to unbiased predictions and are now available
in the package as well, see Puhr et al (2017) <doi:10.1002/sim.7273>.

Georg Heinze

logistf

Firth's Bias-Reduced Logistic Regression

Meinhard Ploner

Daniela Dunkler

Harry Southworth

Lena Jiricka

Gregor Steiner

add1.logistf function

<dl><dt>object</dt>
<dd>A fitted <code>logistf, flic</code> or <code>flac</code> object</dd>
<dt>scope</dt>
<dd>The scope of variables considered for adding or dropping. Should be a
vector of variable names. Can be left missing; the method will then use all variables
in the object's data slot which are not identified as the response variable.</dd>
<dt>data</dt>
<dd>The data frame used to fit the object.</dd>
<dt>test</dt>
<dd>The type of test statistic. Currently, only the PLR test (penalized likelihood
ratio test) is allowed for logistf fits.</dd>
<dt>...</dt>
<dd>Further arguments passed to or from other methods.</dd></dl>

Arguments

Add or Drop All Possible Single Terms to/from a logistf Model — add1.logistf

<dl>

<dt>object</dt>
<dd>A fitted <code>logistf, flic</code> or <code>flac</code> object</dd>


<dt>scope</dt>
<dd>The scope of variables considered for adding or dropping. Should be a
vector of variable names. Can be left missing; the method will then use all variables
in the object's data slot which are not identified as the response variable.</dd>


<dt>data</dt>
<dd>The data frame used to fit the object.</dd>


<dt>test</dt>
<dd>The type of test statistic. Currently, only the PLR test (penalized likelihood
ratio test) is allowed for logistf fits.</dd>


<dt>...</dt>
<dd>Further arguments passed to or from other methods.</dd>

</dl>

add1.logistf: Add or Drop All Possible Single Terms to/from a `logistf` Model

Description

Usage

Value

Arguments

Details

Examples