ANCOVA Endpoint Analysis

Fits change-from-baseline or follow-up ANCOVA with treatment referenced to an explicit control. Reported Cohen d values are unadjusted change-score effects delegated to PhysioExperiment::cohensD() and are separate from the adjusted ANCOVA estimate.

Usage

endpointANCOVA(
  data,
  followup,
  baseline,
  treatment,
  covariates = NULL,
  control = NULL,
  response_scale = c("change", "followup"),
  conf_level = 0.95
)

Arguments

data

Participant-level endpoint data.

followup, baseline, treatment

Scalar column names.

covariates

Optional additional model columns.

control

Control-arm label; defaults to the first observed arm.

response_scale

"change" or "followup".

conf_level

Confidence level for adjusted treatment estimates.

Value

An endpoint_analysis with standardized estimates, the lm fit, complete analysis data, and missingness counts.

Examples

d <- data.frame(
  arm = rep(c("control", "active"), each = 4),
  baseline = rep(0:3, 2),
  followup = c(1, 2, 4, 5, 3, 4, 6, 7)
)
endpointANCOVA(d, "followup", "baseline", "arm")
#> <endpoint_analysis> ancova_change: 1 contrast(s), 8/8 observations used
#>     arm control estimate std_error df statistic      p_value ci_lower ci_upper
#>  active control        2       0.2  5        10 0.0001709476 1.485884 2.514116
#>  cohens_d d_ci_lower d_ci_upper n_arm n_control
#>  3.464102   0.728371   6.199832     4         4