Label a Phase of the Enrollment Flow

Adds a vertical phase label to the left margin of the diagram (e.g., "Enrollment", "Allocation", "Follow-up", "Analysis"). Phase labels span all subsequent steps until the next phase() call or the end of the flow.

Usage

phase(.flow, label)

Arguments

.flow

A selecta object.

label

Character string. The phase label, rendered as rotated text on the left margin.

Value

The updated selecta object with a phase marker appended.

Details

phase() inserts a stage boundary rather than a flow node. Each call opens a phase whose label is drawn in the left margin, spanning every subsequent step until the next phase() or the end of the flow. The purpose of these phase markers is to reflect the stages of analysis in the diagram; as such, they are purely presentational, and they do not alter counts or topology. In the grid engine, phase labels are rendered vertically and are wrapped to fit their band by default; conversely, the dot engine renders phase labels horizontally due to engine limitations.

See also

flowchart for rendering with phase labels

Other flow construction functions: assess(), combine(), endpoint(), enroll(), exclude(), sources(), stratify()

Examples

# Phase labels divide a flow into labeled stages. The printed summary
# marks each phase with a "--- Label ---" banner.
enroll(n = 1200, label = "Records identified") |>
  phase("Enrollment") |>
  exclude("Duplicates", n = 84) |>
  phase("Allocation") |>
  stratify(labels = c("Drug A", "Placebo"), n = c(520, 533)) |>
  phase("Follow-up") |>
  exclude("Lost to follow-up", n = c(23, 31)) |>
  phase("Analysis") |>
  endpoint("Final Analysis")
#> selecta flow (manual mode)
#>   Starting N: 1,200
#>   Steps: 8
#>   --- Enrollment ---
#>   [2] exclude: "Duplicates" (n = 84)
#>   --- Allocation ---
#>   [4] stratify: Drug A, Placebo
#>          label: "Stratified"
#>   --- Follow-up ---
#>   [6] exclude: "Lost to follow-up" (n = 54)
#>   --- Analysis ---
#>   [8] endpoint: "Final Analysis"