SNOMED-CT®, ICD-9CM/ICD-10CM –
Understanding the terminology and technology within these systems

BACKGROUND ON SNOMED:
As Health Information Management changes from a paper/hard copy record to an electronic format the information we store within that data needs to have a standard recognizable system for use between the many different types of electronic records. Coders have the unique perspective of working with many forms of this data such as patient billing systems, encoders, inpatient and outpatient procedures, medical transcription, diagnosis, data analysis, abstraction in addition to the electronic record itself.

SNOMED-CT is a reference terminology system developed by the College of American Pathologists (CAP) back in January of 2002. The SNOMED CT acronym stands for the Systematized Nomenclature of Medicine-Clinical Terms. This data set of terminology was developed to provide a standardized method of electronic common language that electronic health records (HER) can access and use regardless of the EHR software developer.SNOMED CT is a clinical vocabulary available in nearly any language, not just english. This electronic language can cross map to other electronic formats such as ICD-9CM, ICD-10-CM and ICD-10-PCS and HCPCS.

As medical coding and billing transitions to a standard electronic health record format, the usage of a common medical language and terminology system for data to be transmitted and accessed between health care providers and facilities with different software programs becomes a critical issue. The local hospitals and provider offices need to easily exchange data in a back and forth type of flow.

It is this lack of standardization for data exchanges in health information that have been an on-going barrier to providers and facilities in converting to electronic records in healthcare. It is oftentimes difficult for coders and billers to get complete records of documentation if Provider Smith's office uses "ABC software" and Hospital Alpha uses "XYZ software" and the two 'software languages cannot 'speak' to each other.

The usage of SNOMED as a standardized electronic data format language is supported in ANSI, DICOM, HL& and ISO standards for HIPPA transactions and code sets. The U.S. Department of Health and Human Services, has entered into an agreement with College of American Pathologists for a perpetual license for the core SNOMED CT data product and ongoing updates. With this perpetual license, it allows no cost use within the U.S. by both U.S. government including federal, state, local, and private organizations.


SNOMED-CT can be used for many different types of data collection functions. This listing below was taken from the International Health Terminology Standards Development Organization website (ihtsdo.org). It is not an all-inclusive list, but really gives you a good idea of how this information can and is being used in the world today.

• Clinical findings/disorders
• Procedures/interventions
• Observable entities
• Body structures
• Organisms
• Substances
• Pharmaceutical/biologic products
• Specimens
• Special concepts
• Physical objects
• Physical forces
• Events
• Environments/geographic locations
• Social contexts
• Situations with explicit context
• Staging and scales

The next issue that we come up to is the cross-mapping of code-sets for SNOMED-CT to ICD-9 and ICD-10 and HCPCS. Reimbursement and billing requires usage of the ICD-9/ICD-10 and HCPCS code sets. Of course, not all cross-mapping is perfect, but the examples below show how the map works. This cross-mapping is usually a behind-the scenes process that happens with an encoder or an electronic billing/coding system.

SNOMED-CT uses an 8-digit numeric system for classifications, whereas ICD-9 uses a 3 digit primary code with a 1-2 digit extender if needed. ICD-10 and HCPCS use both alpha and numeric systems. As the coder/biller you are the expert, so you should never rely solely on a cross-map. As you can see in the last example in the table, SNOMED-CT has the code for primary infertility cross-mapped to show both a male and a female ICD-9 code

SNOMED CT ICD-9
20897003 atrophy of breast  611.4 atrophy of breast
78623009 endometritis  615.9 unspecified inflammatory disease of uterus
21818003 cataract in degenerative disorder  366.34 cataract in degenerative disorders
297106006 primary infertility  628.9 Female Infertility
297106006 primary infertility  606.9 Male Infertility


In 2009, the Department of Health & Human Services published the standards of how to cross-map SNOMED with ICD-9 and the entire document can be viewed at www.nlm.nih.gov/research/umls/mapping_projects/snomedct_to_icd9cm_reimburse_20091031.pdf


How the SNOMED-CT system works is similar to the progression outlined below. The provider/physician may input the term “headache”, and the SNOMED-CT software would go through the process to find the ‘headache term’, then cross-map and interface with an ICD-9/ICD-10 or HCPCS encoder to populate the query with the multiple codes listed for types of headaches. As the coder/biller, you would then need to review your physician/provider documentation to choose the appropriately mapped code from within the Medical record or billing software and apply the most specific diagnosis possible.


SNOMED Clinical Terms process input 
Clinical finding 
Clinical history and observation findings 
General finding of observation of patient 
Symptom 
Pain 
Pain finding at anatomical site
Pain of head and neck region 
Headache

At this time the National Library of Medicine has the following mapping projects underway.
• SNOMED-CT to CPT
• SNOMED-CT to HCPCS
• SNOMED-CT to ICD-9-CM (for reimbursement)
• SNOMED-CT to ICD-10-CM (for implementation in 2013)

These cross-map interfaces become more and more important as the medical industry transitions to the ‘electronic’ record for e-prescribing, and data collection, and patient billing/management. The SNOMED-CT standardized clinical terms is just one area that helps make a complex data system much more accessible, for all medical providers of care.