CCS_pr9_map: Lookup table for ICD-9-CM (procedure) codes to CCS...

In HunterRatliff1/hcup.data: Datasets Derived From HCUP Software Tools

Lookup table for ICD-9-CM (procedure) codes to CCS categories.

Description

A dataset extracted from the Healthcare Cost and Utilization Project's (HCUP) Clinical Classifications Software (CCS) for ICD-9-CM Procedure codes

Usage

CCS_pr9_map

Format

I9_DX

ICD-9-CM procedure codes, without decimials

CCS

The single-level CCS category

CCS_lvl1

CCS_lvl2

CCS_lvl3

The multi-level CCS categoreis

Details

Single vs Multi-level CCS categories

Unlike the CCSR (CCS Refined), the original CCS classification has "single-level" and "multi-level" categories.

This system classifies all diagnoses and procedures into unique groups. The single-level CCS aggregates diagnoses into 285 mutually exclusive categories and procedures into 231 mutually exclusive categories.

The multi-level CCS expands the single-level CCS into a hierarchical system. The multi-level system has four levels for diagnoses and three levels for procedures, which provide the opportunity to examine general groupings or to assess very specific conditions and procedures. The multi-level CCS groups single-level CCS categories into broader body systems or condition categories (e.g., "Diseases of the Circulatory System," "Mental Disorders," and "Injury").

An example using CCS for diagnosis codes is shown below, but it's similar for procedures

CCS_lvl1	CCS_level2	CCS (single-level)
DX-1	DX-1.1	⁠DX1, DX2, DX3, DX9⁠
DX-1	DX-1.2	DX4
DX-1	DX-1.3	⁠DX5, DX6, DX7⁠
DX-1	DX-1.4	DX8
DX-1	DX-1.5	DX10

It also splits single-level CCS categories to provide more detail. For example, the single-level CCS procedure category 3 (Laminectomy) can be further split into 1.3.1 (Excision of intervertebral disc) and 1.3.2 (Laminectomy).

Further details can be found on the CCS fact sheet.

Problems with the original notation

The notation used in the original CCS categories has a few limitations in how it names categories.

First, the CCS category CCS = '3' maps to "Other bacterial infections" for diagnostic codes, but the same category (CCS = '3') maps to "Laminectomy" for procedures. Second, the CCS category is supposed to be treated as a string (because HCUP designs their software for SAS), but R will appropriately assume these categories are numbers.

The third issue is the ambiguity of single-level and multi-level CCS categories. In the original software, the first level of the multi-level CCS uses the same syntax as the single-level categories. For example, "4" represents "Mycoses" as a single-level category, but maps to "Diseases of the blood and blood-forming organs" as a multi-level category!

This all turns out to be incredibly confusing as the same number "3" could represent:

• "Other bacterial infections" if it's the single-level category for a diagnosis

• "Endocrine; nutritional; and metabolic diseases and immunity disorders" if it's the multi-level category for a diagnosis

• "Laminectomy" if it's the single-level category for a procedure

• "Operations on the eye" if it's the multi-level category for a procedure

Notation used in this package

To address these issues, this package prepends "DX" or "PR" before the default CCS category (e.g. 3 becomes DX3 or PR3 for diagnoses or procedures, respectively). For the multi-level categories, the prefixes are "DX-" and "PR-".

Although this is a trivial change for most applications, it is mentioned here because (for the purposes of reproducibility) this notation should be changed back to the original format for any publications or uses beyond this package.

Source

#' The source documentation used to derive this dataset can be found here.

The single-level and multi-level zip files can be downloaded directly via their respective links.

HunterRatliff1/hcup.data documentation built on Aug. 5, 2023, 2:40 p.m.