R/coding.R

In card: Cardiovascular Applications in Research Data

#' Center for Medicare and Medicaid Services (CMS) Procedure Codes
#'
#' @description This is a generative function used to call CMS procedure codes.
#'   It is used to create a dataset that can be generally used to map procedure
#'   codes to their descriptions, allowing for understanding of interventions
#'   performed. The currently supported codes are explained in the details.
#'
#' The following procedure codes are currently supported:
#'
#' * ICD9 procedure codes, most recently updated on `2014-10-01`
#'
#' * ICD10 procedure codes, most recently updated on `2023-01-11`
#'
#' * HCPCS prcoedure codes, most recently updated on `2023-11-29`
#'
#' * CPT procedure codes, most recently updated on `2023-11-29`
#'
#' @details CMS will usually release updated version of these codes on an annual
#'   basis. Each dataset that is supported below can be identified by the year
#'   it was published (not the *go-live* date, but the *publically-available*
#'   date). The previous versions that are included in the package are as below.
#'
#' * ICD9: 2014
#'
#' * ICD10: 2023
#'
#' * HCPCS: 2023
#'
#' * CPT: 2023
#'
#' @param format The format of the procedure codes, written as a `character`.
#'   Currently supported formats are: `c("icd9", "icd10", "hcpcs", "cpt")`
#'   (case-insensitive).
#'
#' @param version The version of the procedure codes, which are generally
#'   written as a year. Currently supported: `c("2014", "2023")`
#'
#' @returns A `tbl_df` with two columns: `code` and `description`. The `code`
#'   refers to the procedure code, while the `description` refers to the
#'   description of the procedure.
#'
#' @examples
#' # Procedure codes from the 2014 version of ICD-9
#' icd9 <- procedure_codes(format = "icd9", version = 2014)
#'
#' @name procedure_codes
#' @export
procedure_codes <- function(format, version) {

	# Identify which dataset to use based on format code
  # 	Check if the format is supported
	# 	Add checks to see if version is supported
  # 	Check if the version is supported
	if (length(format) > 1) {
		stop("Only one format can be referenced at a time.")
	}

  if (!format %in% c("icd9", "icd10", "hcpcs", "cpt")) {
    stop("Format not supported. Please use one of the following: icd9, icd10, hcpcs, cpt")
  }

	version <- as.character(version) # In case is numeric

	if (length(version) > 1) {
		stop("Only one version can be referenced at a time.")
	}

	if (format == "icd9") {
	  if (!version %in% c("2014")) {
	    stop("Version not supported. Please use one of the following: 2014")
	  }
	}

	if (format == "icd10") {
	  if (!version %in% c("2023")) {
	    stop("Version not supported. Please use one of the following: 2023")
	  }
	}

	if (format == "hcpcs") {
	  if (!version %in% c("2023")) {
	    stop("Version not supported. Please use one of the following: 2023")
	  }
	}

	if (format == "cpt") {
	  if (!version %in% c("2023")) {
	    stop("Version not supported. Please use one of the following: 2023")
	  }
	}

	dat <- .cms_codes[[format]][[version]]

	# Return dataset
	return(dat)
}