ICD to HCC

Generate Medicare Hierchical Condition Categories (HCC) based on ICD codes

Introduction

• many to many relationship
• ICD9/10 are mapped to Condition Categories (CC), and a hierarchy based on disease severity is applied to the CCs to generate HCCs.

Data

The ICD/HCC mappings were obtained from CMS. CMS provides SAS macros for assigning HCCs and HCC scores based on ICDs, adjusted annually. We have implemented assigning HCCs (but not scores) in R. The original data is available from CMS, or in the github repository at /crosswalks/originalCMS_xw.

Between 2007-2012, there were 70 HCCs (Version 12). In 2013, this was expanded to 87 (Version 20). We use the labels for the more inclusive mappings (post-2013) for all years for consistency. This means that in pre-2013 data 17 HCCs will be structurally zero.

Source

icdtohcc.R

• Import condition categories, hierarchy rules, and labels, by year from CMS (for both ICD9/10)
• Apply CCs and implement hierarchies to generate HCCs, starts with wide patient data, ends with long data Source with markdown

Future Plans

• split into separate functions
• ?incorporate into icd package