grf.subg.eval

Evaluates the performance of GRF-identified subgroups, including hazard ratios,
bias, and predictive values. This function is typically used in simulation studies
to assess the performance of the GRF subgroup identification method.

internal

Implements statistical methods for exploratory subgroup identification
in clinical trials with survival endpoints. Provides tools for identifying
patient subgroups with differential treatment effects using machine learning
approaches including Generalized Random Forests (GRF), LASSO regularization,
and exhaustive combinatorial search algorithms. Features bootstrap bias
correction using infinitesimal jackknife methods to address selection bias
in post-hoc analyses. Designed for clinical researchers conducting exploratory
subgroup analyses in randomized controlled trials, particularly for
multi-regional clinical trials (MRCT) requiring regional consistency
evaluation. Supports both accelerated failure time (AFT) and Cox proportional
hazards models with comprehensive diagnostic and visualization tools.
Methods are described in León et al. (2024) <doi:10.1002/sim.10163>.

Larry Leon

forestsearch

Exploratory Subgroup Identification in Clinical Trials with
Survival Endpoints

grf.subg.eval function

<dl><dt>df</dt>
<dd>Data frame containing the analysis data.</dd>
<dt>grf.est</dt>
<dd>List. Output from <code>grf.subg.harm.survival</code>.</dd>
<dt>dgm</dt>
<dd>List. Data-generating mechanism (truth) for simulation.</dd>
<dt>cox.formula.sim</dt>
<dd>Formula for unadjusted Cox model.</dd>
<dt>cox.formula.adj.sim</dt>
<dd>Formula for adjusted Cox model.</dd>
<dt>analysis</dt>
<dd>Character. Analysis label (default: "GRF").</dd>
<dt>frac.tau</dt>
<dd>Numeric. Fraction of tau for GRF horizon (default: 1.0).</dd></dl>

Arguments

GRF Subgroup Evaluation and Performance Metrics — grf.subg.eval

<dl>

<dt>df</dt>
<dd>Data frame containing the analysis data.</dd>


<dt>grf.est</dt>
<dd>List. Output from <code>grf.subg.harm.survival</code>.</dd>


<dt>dgm</dt>
<dd>List. Data-generating mechanism (truth) for simulation.</dd>


<dt>cox.formula.sim</dt>
<dd>Formula for unadjusted Cox model.</dd>


<dt>cox.formula.adj.sim</dt>
<dd>Formula for adjusted Cox model.</dd>


<dt>analysis</dt>
<dd>Character. Analysis label (default: "GRF").</dd>


<dt>frac.tau</dt>
<dd>Numeric. Fraction of tau for GRF horizon (default: 1.0).</dd>

</dl>

grf.subg.eval: GRF Subgroup Evaluation and Performance Metrics

Description

Usage

Value

Arguments