Create a first-recorded-value feature specification

Produces a feature spec that extracts the value from the earliest record matching the concept set. Ordered by the table's date column, the first record's value_column is returned. Useful for capturing baseline measurements at initial presentation.

Usage

omop.feature.first_value(
  concept_set,
  value_column = "value_as_number",
  name = NULL
)

Arguments

concept_set

Numeric vector of concept IDs, or an omop_concept_set object defining the concepts to match.

value_column

Character; name of the column from which to extract the value (default "value_as_number").

name

Character; optional custom name for the feature column. If NULL, auto-generated from the concept and table context.

Value

An omop_feature_spec object with type = "first_value".

See also

ds.omop.plan.features, omop.feature.latest_value, omop.feature.mean_value

Examples

if (FALSE) { # \dontrun{
spec <- omop.feature.first_value(c(3004410),
  value_column = "value_as_number")
plan <- ds.omop.plan.features(plan, "labs",
  "measurement", specs = list(initial_glucose = spec))
} # }