Get descendant concepts via the concept_ancestor table

Traverses the OMOP concept_ancestor hierarchy on each connected server and returns all descendant concepts for the given ancestor IDs. This is the standard way to expand a high-level concept (e.g., "Diabetes mellitus") into all of its more specific child concepts.

Usage

ds.omop.concept.descendants(
  ancestor_ids,
  include_self = TRUE,
  symbol = "omop",
  conns = NULL,
  execute = TRUE
)

Arguments

ancestor_ids

Integer or numeric vector of ancestor concept IDs to expand (e.g., c(201820)).

include_self

Logical; if TRUE (the default), the ancestor concepts themselves are included in the result alongside their descendants.

symbol

Character; the session symbol used when the OMOP connection was initialised (default: "omop").

conns

DSI connection object(s). If NULL (the default), the connections stored in the active session are used.

execute

Logical; if FALSE, returns a dry-run dsomop_result containing only the reproducible R code without contacting the servers.

Value

A dsomop_result object with scope = "pooled" (a de-duplicated cross-site view of the shared vocabulary; per-site frames remain available). Each server's result is a data frame of descendant concept rows.

Examples

if (FALSE) { # \dontrun{
# Get all descendants of "Type 2 diabetes mellitus" (concept 201826)
desc <- ds.omop.concept.descendants(201826)
nrow(desc$per_site[[1]])

# Exclude the ancestor itself
desc <- ds.omop.concept.descendants(201826, include_self = FALSE)
} # }