build_def {healthdb}

Build case definition function calls

Description

This function assembles function calls from the supplied functions and their required arguments, leaving the data argument empty for easy re-use of the definition calls with different data and batch execution (see execute_def() for detail). It is useful for defining multiple diseases/events across multiple sources.

Usage

build_def(def_lab, src_labs, def_fn = define_case, fn_args)

Arguments

def_lab

A single character label for the definition, e.g., some disease.

src_labs

A character vector of place-holder names for the data sources that will be used to execute the definition.

def_fn

A list of functions (default: define_case()) that will filter the source data sets and keep clients met the case definition. The length of the list should be either 1 or equal to the length of src_labs. If length = 1, the same function will be applied to all sources; otherwise, def_fn should match src_lab by position. User can supply custom functions but must put input data as the first argument and name it data.

fn_args

A named list of arguments passing to the def_fn. Each element in the list should have the same name as an argument in the source-specific def_fn, and the element length should also be either 1 or equal to the number of sources. If you have def_fn functions taking different sets of arguments, include the union in one list.

Value

A tibble with a number of rows equal to the length of src_labs, containing the input arguments and the synthetic function call in the fn_call column.

Examples

sud_def <- build_def("SUD", # usually a disease name
  src_lab = c("src1", "src2"), # identify from multiple sources, e.g., hospitalization, ED visits.
  # functions that filter the data with some criteria,
  # including mean here for src2 as a trivial example
  # to show only valid arguments will be in the call
  def_fn = list(define_case, mean),
  fn_args = list(
    vars = list(starts_with("diagx"), "diagx_2"),
    match = "start", # "start" will be applied to all sources as length = 1
    vals = list(c("304"), c("305")),
    clnt_id = "clnt_id",
    # c() can be used in place of list
    # if this argument only takes one value for each source
    n_per_clnt = c(2, 3),
    x = list(1:10) # src2 with mean as def_fn will only accept this argument
  )
)

# the result is a tibble
sud_def

# the fn_call column stores the code that can be ran with execute_def
sud_def#fn_call