National DIMDI project "Kodierung von Seltenen Erkrankungen" (Rare diseases coding)
In order to code rare diseases specifically in Germany, Orpha numbers should be used in addition to the ICD-10-GM code which is compulsory in inpatient and outpatient routine coding. Therefore coders would need to use two coding systems.
The goal of the DIMDI project "Rare diseases coding" was to improve the coding of rare diseases and to simplify this "double" coding process. The project was initiated in July 2013 andended in October 2019 as an initiative in the context of the National Action Plan for People with Rare Diseases. The project was financed by the Federal Ministry of Health (BMG).
Addition of rare diseases to the Alphabetical Index of ICD-10-GM and Alpha-ID
This project initially reviewed whether all rare diseases listed in the Orphanet nomenclature are included in the Alphabetical Index of ICD-10-GM. Diseases that were not included were added and assigned to an ICD-10-GM category. In addition, there has been a reconciliation with Orphanet for all ICD-10 codes that were already mapped to the rare diseases of the Orphanet nomenclature.
This first step led to a better representation of rare diseases in ICD-10-GM and thus to improved coding.
When a rare disease is added to the software version of the Alphabetical Index of ICD-10-GM, a specific identification number is assigned to every term. With this specific identification number and the ICD-10-GM code rare diseases are then also included in the Alpha-ID file, which BfArM publishes on an annual basis.
Alpha-ID-SE with Orpha numbers
To further improve the documentation of rare diseases, Orpha numbers were added to the rare disease entries of the Alpha-ID and published in a project-specific test file, the Alpha-ID-SE. This connection of ICD-10-GM codes and Orpha numbers in the Alpha-ID-SE makes it possible to code rare diseases in Germany in a more differentiated and specific manner by means of one single file.
The "Musterdatensatz", an extract of the test file Alpha-ID-SE that was produced within the framework of the project, was a sample data set that only included rare diseases with the assigned Orpha number. A test implementation of this "Musterdatensatz" was performed in 4 selected reference centers for rare diseases as part of the project. The "Musterdatensatz" was successfully implemented and used. From the 2-year-experience gained the selected reference centers derive the recommendation to continue the availability of the Alpha-ID-SE and to introduce a mandatory use in centers for rare diseases.
The following exemplary extract from the file Alpha-ID-SE shows that synonymous terms of rare diseases such as, for instance, Fibrodysplasia ossificans progressiva and Münchmeyer-Syndrom have the same Orpha number (337) and the same ICD-10-GM code (M61.19), but different Alpha-ID codes: This is the concept of Alpha-ID, every text entry has its own Alpha-ID code.
Please note that the Alpha-ID is based on the Alphabetical Index of the ICD-10-GM, and that Alpha-ID codes are only assigned to diagnostic terms in German language. Therefore the use of Alpha-ID codes for files in other languages does not apply.
The file also shows that several distinct rare diseases such as, for instance, the Zerebro-hepato-renales Syndrom (Cerebrohepatorenal syndrome) and Lymphödem mit Hypoparathyreoidismus (Lymphedema-hypoparathyroidism syndrome) may be assigned the same ICD-10-GM code (Q87.8), but aside from different Alpha-ID codes may also have different Orpha numbers (912 and 1563 respectively). This example shows that distinguishable diseases can not be identified by using only the ICD-10-GM code.
The example of the file below also clarifies the relation between the ICD-10-GM code and the Orpha number, for instance: diseases like Apfelschalensyndrom (Apple peel syndrome), Jejunalatresie (Jejunal atresia) and Dünndarmatresie (Atresia of small intestine), may all have the same Orpha number (1201) but in some cases a different ICD-10-GM code (in this case Q41.1 or Q41.9). It illustrates the diverse criteria two different systems, like the Orphanet rare disease nomeclature and the ICD-10-GM use to classify diseases. In this case the ICD-10-GM uses the localization as further classification criteria (Q41.1 concerns the atresia of jejunum and Q41.9 the atresia of the small intestine, part unspecified).
In case of the synonyms Intestinale Lipodystrophie (Intestinal lipodystrophy) and Whipple-Krankheit (Whipple disease), which have the same Orpha code (3452), one synonym is coded with a single ICD-10-GM code (K90.8), the other one with an additional asterisk code (K90.8+ M14.89*) to indicate the manifestation.
Excerpt from the files Alpha-ID-SE and "Musterdatensatz"
| Alpha-ID-Code | ICD-10-GM-Code | ICD-10-GM-Additional (Asterisk) Code | Orpha Number | Diagnostic Term |
|---|---|---|---|---|
| I5821 | K90.8 | 3452 | Intestinale Lipodystrophie | |
| I24937 | K90.8+ | M14.89* | 3452 | Whipple-Krankheit |
| I32050 | M61.19 | 337 | Fibrodysplasia ossificans progressiva | |
| I81949 | M61.19 | 337 | Münchmeyer-Syndrom | |
| I82889 | Q41.1 | 1201 | Apfelschalen-Syndrom | |
| I118177 | Q41.1 | 1201 | Jejunalatresie | |
| I17291 | Q41.9 | 1201 | Dünndarmatresie | |
| I9222 | Q87.8 | 912 | Zerebro-hepato-renales Syndrom | |
| I118259 | Q87.8 | 1563 | Lymphödem mit Hypoparathyreoidismus |
The file Alpha-ID-SE is a basis for the completion of other actions of the National Plan of Action for People with Rare Diseases (NAMSE), for example the creation of a registry prototype or the "se-atlas" (a web portal that maps care providers for persons with rare diseases). NAMSE included the use of the Alpha-ID-SE as a key in the catalogue of requirements of type-A and type-B centers of centers for rare diseases in 2019.
Furthermore, the file is available to any user who strives to create a differentiated depiction of rare diseases. For example, the access to information from Orphanet regarding certain rare diseases can be simplified via the connection of ICD-10-GM codes and Orpha numbers by providing corresponding references to Orphanet for the user during the coding process with ICD-10-GM.
Alpha-ID-SE is included as electronic version TXT (CSV) in the ZIP file for Alpha-ID. It is updated annually. The currently valid version is effective from the beginning until the end of a calendar year. The Alpha-ID-SE file is attached to the zip file of Alpha-ID.
The "Musterdatensatz" as a project-specific extract from Alpha-ID-SE has been provided for the last time in the version 2020.
Within the project flyers for medical coders and software producers as well as a recommendation document for the implementation of the Alpha-ID-SE in German language were developed in collaboration with the 4 reference centers for rare diseases.
Flyer for medical coders (PDF, 133,1 kB)
Flyer for software producers (PDF, 147,1 kB)
Recommendations for the implementation of the Alpha-ID-SE (PDF, 270,8 kB)
Furthermore, a training presentation for the use of the Alpha-ID-SE for medical coders is available in German language and can be requested via klassi@bfarm.de at BfArM.
Further information on the national DIMDI-Project
National Plan of Action for People with Rare Diseases (PDF, 2,3 MB)
National Action League for People with Rare Diseases (NAMSE)
se-atlas Mapping of Health Care Providers for people with rare diseases