Feature request: charlson_sundararajan2004

[dewittpe]

During the R/Medicine 2026 conference, @DesiQuintans asked

Is there support for ICD code versions from other countries, e.g. ICD-10-AM from Australia?

@dewittpe replied:

Not yet, but I would love to add them to the package! Is there a good reference where I can get the ICD-10-AM specific codes?

@DesiQuintans replied with links and notes:

https://www.jclinepi.com/article/S0895-4356(04)00164-7/abstract
The comorbidity package has Quan-adjusted Elixhauser and Charlson for ICD-10-AM, and I contributed chronic condition "u-codes" to it also. https://github.com/ellessenne/comorbidity/blob/master/data-raw/make-mapping.R

Adding the Sundararajan et.al. (2004) codes will be easy enough. The harder part to start is getting a good reference for the ICD-10-AM codes.

[dewittpe]

To get the sundararajan_2004 method into the current workflow I would need a machine readable reference for ICD-10-AM. My initial searches suggest such a reference may not exist.

Alternative: extend the initial ICD to comorbidity mapping in medicalcoder::comorbidities() to use regex instead of the database joins optionally for the existing methods and manditory for methods based on ICD systems not included in the internal ICD database.

[DesiQuintans]

Hi Peter, what requirements do you have for a "machine readable reference"? A dataframe of codes, dates instated/obseleted, descriptions, etc?

The electronic code lists can be licensed from IHACPA (an Australian government agency) at no cost for non-commercial research, but the application takes a long time to process. I am happy to place a licensing application for medicalcoder since I am located in Australia, but it may take some back-and-forth.