Estimate the baseline-outcome correlation (for ANCOVA planning)

From pilot data - a pair of numeric vectors, a data.frame with a baseline and follow-up column, or a PhysioCohort cohortDesign() plus column names - estimate \(\rho\) to feed sampleSizeANCOVA().

Usage

estimateBaselineCorrelation(
  baseline,
  followup = NULL,
  cols = NULL,
  method = "pearson"
)

Arguments

baseline

A numeric vector of baseline values, a data.frame, or a PhysioCohort.

followup

A numeric vector of follow-up values (when baseline is a vector).

cols

Length-2 character vector naming the baseline and follow-up columns (when baseline is a data.frame / cohort design).

method

Correlation method (default "pearson").

Value

The estimated correlation (numeric).

See also

sampleSizeANCOVA()