SNOMED Usage Guide for Veterinary Systems:

Saying what we want to say.

AVHIMA

July 18, 2001

Boston, MA

Collaborators

• Bobbi Schmidt

• Kathy Ellis

• Dr. Penny Livesay

• Dr. Kurt Zimmerman

• Dr. Larry Freeman

• Dr. Cynthia Wheeler (ACVO)

Usage Guide “Preamble”

• A (specific) medical record system provides the context for the use of medical language.

• SNOMED provides semantic “values” that can be used appropriately in medical record systems.

• No single Guide can guarantee appropriate use of SNOMED for all medical records systems.

Usage Guide “Preamble”

• Both SNOMED and the medical record system may influence the meaning of a (end-user constructed) concept phrase.

• Both SNOMED and the medical record system architecture may influence the retrievability of a concept phrase.

Usage Guide “Preamble”

• SNOMED is concept-based not code-based.– A SNOMED concept has a single meaning.

– SNOMED is not currently providing precise English language-based definitions of concepts. Meaning can be inferred from relationship-based definitions and hierarchy position.

– Until additional features are added, selection of concepts should be based (ONLY) on the fully specified name of the concept.

Usage Guide “Preamble”

• SNOMED is hierarchy-based not code-based.– The meaning of a particular concept name may only

be made clear by examining the position of a concept in a hierarchy

– References to code “types” (D, M, F) does not confer reliable information about appropriate uses of concepts.

– Values sets for particular record fields or for concept phrases should be evaluated critically. Specific subsets of SNOMED can be derived for specific purposes.

Usage Guide “Preamble”

• The use of SNOMED specified by this document imposes certain fundamental restrictions on any system:– The system must support data storage and

transmission that maintains discrete code phrases based on object-attribute-value triples.

– The system owner must own a valid license for SNOMED.

Birth

• Type of Delivery (Dystocia)– Delivery procedure vs. delivery diagnosis?

• Conditions affecting Newborn includes maternal? (Whazzat?)

Biopsy

• A biopsy code is not assigned when a lesion removed for therapeutic purposes is sent to pathology for examination even though the term biopsy may be used.

• Closed biopsies are sometimes performed even though the operation itself is an open procedure. In these cases, the open procedure is also coded. (i.e. Laparotomy with needle biopsy of liver; code both the laparotomy and the biopsy) – VMDB Coding guideline draft (6/20/2001).

Biopsy

• So, if I do an open procedure and add a closed biopsy, I code the biopsy. If I do an open procedure and I do an open biopsy, I don’t code the biopsy? – Sounds very much like a policy decision, not a “retrieval-

criterion-based” decision.– State an unambiguous definition for “biopsy”

• is it the intent to gather diagnostic information by tissue submission (it is to me)?

– OR

• is it an administrative category based on the specific procedures employed to deliver the diagnostic sample to the laboratory?

Colic

• Code Colic (F-50820) in addition to the Final Diagnoses listed, if it is the reason for admission.– VMDB Coding guideline draft (6/20/2001)

Colic

• Reason for admission and diagnosis should be two different fields.– Inconsistent capture of “reason for admission” in

diagnosis field.• Why does Equine Colic deserve special attention?

– Addition of Colic to a diagnosis field DOES NOT identify the Colic as reason for admission.

• Partly BECAUSE Colic is also used as “the diagnosis”

Colic

Colic

• F-50820 is the “finding” called abdominal pain.• Equine clinicians elevate the “finding” to the level of

disorder.• We still need to capture vague colic (resolved

spontaneously, no other diagnosis rendered).– Is F-50820 “Abdominal colic (finding)” adequate for this

purpose?

• Does the medical record system sanction the use of clinical signs as final diagnosis? – Is this decision made on a disease-by-disease basis (policy

decision) ?

Complications (Postoperative)

• Use codes in DD-66000 category (hierarchy) – Complications of surgical procedure

• Choose the most specific applicable. Always – Mechanical – complications which result from some

failure of an internal device, implant, or graft, such as a displacement or malfunction. This term includes such things as catheters.

– Nonmechanical/Postoperative - Abnormal reactions to the presence of a device, implant, or graft that is functioning properly are coded to the appropriate complication code.

• VMDB Coding guideline draft (6/20/2001).

Complications (Post-procedure)

• If there is no structural or philosophical difference in approach, all procedure complications should be managed the same way.– “…includes such things as catheters”

• Complication of procedure (disorder) DD-60002?• I THINK this also extends to adverse drug reactions if

therapy was administered.• It will be difficult to maintain accuracy at the

“Mechanical” non-mechanical level. – Better to support this with free text elsewhere in the

document? (is this worth recording in an abstract?)

Clinical Scenario

• Patient is presented to ophthalmology service for evaluation

• Prior diagnosis of diabetes mellitus is present in previous records (from “reliable” referring DVM).

• Diagnosis of diabetic cataract is made.

Diabetic cataract

• When there is a causal relationship between the diabetes and a complicating condition, the type of diabetes is coded first, followed by the type of diabetic manifestation and the code to identify the complication.– VMDB Coding guideline draft (6/20/2001)

Diabetic Cataract

• DB-61010 - Insulin dependent diabetes mellitus

• DB-61510 - Ophthalmic manifestations of diabetes

• DA-73840 - Diabetic cataract

Diabetic Cataract DA-73840

Is a Cataract 62795009 DA-73500

Is a Diabetic oculopathy

25093002 DB-61510

Associated morphology

Cataract 128306009 M-54510

Associated topography

Crystalline lens

78076003 T-AA700

Diabetic Cataract DA-73840

• Already inherits (is a) Diabetic Oculopathy (Ophthalmic manifestations of diabetes )

• In SNOMED-CT, will inherit – HAS_ASSOCIATED_ETIOLOGIC_FINDING

• Diabetes mellitus (DB-61000)

Diabetic Cataract DB-61010

• Other general concerns with approach:– The coding ORDER (in the system) does not control the

association between the concepts.• Relationship between codes must be made EXPLICIT in the medical

record system.

– Diabetic Cataract is ALWAYS Associated with Insulin dependency?

– What if insulin dependency is established in diagnoses rendered prior to the cataract? Is this coded whether or not the secondary provider confirms the diagnosis (administrative decision)?

– This is a specialized case of “secondary” disease described differently in the document.

Due to

• When coding a diagnosis “due to” or “secondary to” another diagnosis, code the causative / principal condition first followed by the resulting / secondary condition. Use DF-00150 with the secondary diagnosis. (Example: Seizures due to fever. Use the D-code with the code for seizures.) Use only if not included/implied in the diagnosis code description in SNOMED (i.e. secondary cataracts).

• Exception: Do not use the DF-00150 codes for conditions due an external cause/injury; i.e. HBC, poisoning, etc.

• **Need to discuss on Forum what codes to use**

– VMDB Coding guideline draft (6/20/2001)

Due to

• HAS_ASSOCIATED_ETIOLOGIC_FINDING (Relationship)– To distinguish from “complications of

procedure”

• How much flexibility (expressiveness) do you expect for “value set” used in this relationship?– Single codes? Code phrases?

Fracture

• Fractures should be coded with the appropriate D-code by site followed by an M-code for fracture type if specified. A T-code can be used if necessary to specify the site more fully. Do Not use combination codes for multiple fractures (e.g. fracture of radius and ulna). Use individual codes for each site/bone.

• Any fracture that is not specified as open is coded as closed. Open indicates that the bone has punctured the skin; a closed fracture has not penetrated the skin. Closed fractures are described by a variety of terms, such as comminuted, depressed, green stick, impacted, simple and spiral. Open fractures include compound, infected, missile, puncture, and with foreign body.– VMDB Coding guideline draft (6/20/2001)

Fracture

• Fractures should be coded: – D-code by site – M-code for fracture type if specified.

• comminuted, depressed, green stick, impacted, simple and spiral, compound, infected, missile, puncture, and with foreign body.

– A T-code can be used if necessary to specify the site more fully.

• Do Not use combination codes for multiple fractures (e.g. fracture of radius and ulna). Use individual codes for each site/bone.

• Open vs closed should only be included if specified. Default use of “closed” when closed or open is not specified should be an system-specific internal rule (administrative decision).

Grafts of Bone or Skin

• Code the P code for “Excision / Harvesting of the bone or skin for graft”. For Bone Grafts, if you can not obtain a code that specifically lists the bone you are harvesting from, then use the P1-10332 and a T code for the bone. For Skin Grafts, use P1-40D04 and a T code for where the skin is removed. – VMDB Coding guideline draft (6/20/2001)

Grafts of Bone or Skin

• Code the P code for “Grafting of bone or skin by ‘site’ ” and code for type of graft (Autograft or Allograft). If code by site is not available, use P1-10D00 (bone graft) or P1-40D00 (Skin graft) and T code for where graft was placed.

Grafts of Bone or Skin

• When a fully specified (topography included) procedure code does not exist, select the most specific parent available– Pedicle graft– Myocutaneous graft

• Additional modifiers– Graft types (layers)– Graft morphologies (slit grafts)

Disorder secondary to adverse drug reaction.

• If a condition is caused by properly administered medications and is diagnosed as iatrogenic, code DD-64800 + C code if stated + Iatrogenic condition.– VMDB Coding guideline draft (6/20/2001).

Iatrogenic hypothyroidism

• What distinguishes “iatrogenic” disease from other adverse drug reactions?

• Is it:– Hypothyroidism

• Has associated etiologic finding– Adverse drug reaction

» Associated etiology:Methimizole

• Is it:– Iatrogenic hypothyroidism

• Associated etiology Methimazole?

Late Effects

• A late effect is the residual effect that remains after the termination of the acute phase of an illness or injury. Complete coding of late effects usually requires two codes: 1) Residual condition or nature of late effect; 2) Cause of the late effect. The residual condition is sequenced first followed by the cause of the late effect.– VMDB Coding guideline draft (6/20/2001).

Late Effects

• Late effects of trauma have a relatively rich hierarchy and seem somewhat logical.

• Late effects of diseases do not.

Leukemia

• Code with the appropriate D-code specifying the type of leukemia and the M-code for the morphological type of Leukemia. Exception: Feline Leukemia code as DE-36030. – VMDB Coding guideline draft (6/20/2001).

Leukemia

• What makes this special? (Needs to be handled in the neoplasia section – we’ll figure it out there )

• Feline leukemia is not an exception, it just has its own code. We need to make sure that the feline leukemia “model-definition” is accurate. (It’s just a very specific “kind-of” leukemia).– The DE-36030 concept is only “cat is infected”. We need

additional concept(s) for manifestation of disease.– New concepts should be added to the leukemia hierarchy.

Limb Sparing

1) Code the P code for “Excision of lesion from the ‘bone’ ” and/or “Partial resection/ostectomy of ‘bone’ ” and the T-code for the bone you are removing.

2) Code the P code for “Excision / Harvesting of the bone for graft”. If you can not obtain a code that specifically lists the bone you are harvesting from, then use the P1-10332 and a T code for the bone.

3) Code the P code for “Grafting of bone by ‘site’ ” and code for type of graft (Autograft or Allograft)

4) Code chemotherapeutic implant if performed.– VMDB Coding guideline draft (6/20/2001).

Limb Sparing

• Limb sparing really serves as a specific example for “multiple-surgery” procedure groupings.

• Administrative or medical category?

• Is there an “organ sparing” category?

Lipoma

• Code with the appropriate D-code specifying site and M-88500 (Lipoma).

• VMDB Coding guideline draft (6/20/2001).

– Children of “Lipoma (clinical disorder)” D1-F2800?

– Code like ANY other benign neoplasm?

Lipoma

Luxation / Subluxation

• Luxations and Disarticulations are to be coded as “Dislocations” except for when the problem is listed only under Luxation (i.e. lens or patellar).

• For Subluxations use the appropriate code under “ Subluxation.”– VMDB Coding guideline draft (6/20/2001).

Luxation / Subluxation

• Disarticulation is a procedure

• Patellar luxation (disorder) IS A joint dislocation – Examine the hierarchy not the text string.

Mass

• Masses should be coded with the appropriate D-code specifying site. If there is no D-code available then code Localized Mass M-03000 AND the appropriate T-code.– VMDB Coding guideline draft (6/20/2001).

Mass

Mass

• appropriate D-code specifying site– e.g., Abdominal mass (disorder) D5-02004

• Or, most specific disorder– e.g., Disorder of abdomen

• Fold these into tumors / neoplasms ?

Neoplasm / Tumors

• Neoplasms should be coded with the appropriate D-code based on anatomical site (e.g. Benign/Malignant Neoplasm of the spleen) followed by an M-code (e.g. Hemangiosarcoma) and a G-code for histologic grading, differentiation, and behavior. G-F505 should be entered if differentiation is not determined. Other clinical staging G-codes are optional.– VMDB Coding guideline draft (6/20/2001).

Neoplasm / Tumors

• If the site is unknown, then use D code of Neoplasm of unspecified site. If morphology is not specified to cell type then use M-8000* (e.g. Malignant Neoplasm, Benign Neoplasm)– VMDB Coding guideline draft (6/20/2001).

Neoplasm / Tumors

• The following neoplasms should be coded with the appropriate D-code based on morphology type (e.g. Lymphoma of cervical lymph nodes) followed by the proper

• M-code and G-code– Hemangioma, Leukemia (See Leukemia), Lipoma (See Lipoma),

Lymphoma / Lymphosarcoma (use key term Lymphoma), Mast Cell Tumors – Malignant use M-97403, Benign use DC-47000 and M-97401, Melanoma (of the skin only), Multicentric Lymphoma – If neoplasm is not of skin and is Stage 3 or 4, then it is considered multicentric.

• Wart/Papilloma (See Wart/Papilloma)

– VMDB Coding guideline draft (6/20/2001).

Neoplasm / Tumors

• Tumors should be coded with the appropriate D-code for Neoplasm of Uncertain Behavior by site with M-80001.

•  Use the Chemotherapy procedure code P2-67010 for oncology cases only.– VMDB Coding guideline draft (6/20/2001)

• P2-67010 is parent for chemotherapies that ARE NOT for treatment of malignant disease – it doesn’t mean “cancer chemotherapy”

Neoplasm / Tumors

• We got work to do!

Normal Patient / Wellness Exam

• For a patients with a diagnosis of Normal / Healthy with NO EXAM PERFORMED (e.g. Mare with Foal, Boarding, etc.) use F-00001 – Normal Patient Condition for the diagnostic code.

• For a Wellness Exam or Healthy Patient with an EXAM PEFORMED use – F-06800 – Wellness State for the diagnostic code.

• Note: Do not use these codes if another diagnosis is listed on the record.– VMDB Coding guideline draft (6/20/2001)

Normal Patient / Wellness Exam

• F-00001 – Normal Patient Condition for the diagnostic code.

• F-06800 – Wellness State for the diagnostic code.– These two codes are not distinguished on the basis of

the examination performed (or lack thereof).– Wellness state is (probably) a group header for the list

of wellness states that can be used as values here. (Well adult, etc.)

• Does a physical exam result (Normal Patient Condition) belong in the diagnosis field?

Open wounds without complications

• Open wounds should be coded as Open wound by site (Concept: Open wound and/or crushing injury - DD-30000). Also code the M code to identify the type of wound:

• M-14400 Laceration, M-14120 Avulsion/Degloving, M-14300 Puncture Wound, M-14374 Bite Wound, M-145** Gunshot Wound, M-14700 Abrasion

• **Note: If there is no code by site available, then use DD-30010 for Open wound without complication and specify the site with a T code. – VMDB Coding guideline draft (6/20/2001)

Open wounds with complications

• Open wounds are coded as being complicated when any of the following circumstances are associated with them. Use M codes to describe the complication and the type of wound (see list above):

• Delayed healing (M-78330), Delayed treatment, Foreign Body in wound (M-30400 + substance code), Major Infection, Sequestrum / Necrosis

• **Note: If there is no code by site available, then use DD-30020 for Open wound with complication and specify the site with a T code.– VMDB Coding guideline draft (6/20/2001)

Open wound with infection

• Infection – Has associated etiologic finding = wound

• Open wound– Has associated complication = infection

• These two are the same “concept? ”

• Can we construct and retrieve either or both?

Poisoning / Ingestion / Toxicity

• Conditions caused by drugs, medicinal substances, and other biological substances due to animal’s exposure to the substance are classified as poisonings when the substance involved is not used in accordance with a clinician’s instructions. Such as:– Wrong Medication given or taken, Wrong dosage given or taken ,

Overdose, Intoxication, Toxic Effects of non medicinal substances, Ingestion or other exposure of a substance

• Adverse effects resulting from the proper administration of the correct substance (prescription drug for patient) are excluded from poisoning. Under these circumstances, code as an adverse effect or reaction (DD-64800).

– VMDB Coding guideline draft (6/20/2001)

Poisoning / Ingestion / Toxicity

• Language needs to reconcile with “Adverse drug reaction”– “when the substance involved is not used in accordance with a

clinician’s instructions”

– “If a condition is caused by properly administered medications”

• There are additional perspectives on “wrong medication”– Administrative (Drug A was ordered, Drug B delivered)

– Medical (Drug A was ordered, it was the wrong drug)

– Medical (Drug A was ordered, it was the right drug, the patient didn’t tolerate the usual dose).

Procedure

• Therapy administered to the patient should be indicated with the appropriate P code. Use the most specific code available to describe the procedure. You may need to add an additional P code, topography (T), morphology (M), Chemical (C) or Device (A) code(s) to fully describe a procedure.– VMDB Coding guideline draft (6/20/2001)

Procedure

• Procedures are much more difficult to compose than are findings.

• “Procedure” hierarchy has generated much discussion lately and it’s not completely resolved.

Rechecks

• For Rechecks of a previous medical diagnosis, previously listed in the medical record of the institution holding the record, use G-1001 (prior diagnosis) as a modifier for the diagnosis/disease being rechecked. Confirmation of a diagnosis at a referral institution would be considered the original diagnosis and not a recheck.

• For a surgical recheck, use F-06030 (postop status). – VMDB Coding guideline draft (6/20/2001)

Rechecks

• Confirmation of a diagnosis at a referral institution would be considered the original diagnosis and not a recheck.– Is diabetes mellitus (established by a referring vet) a

“prior” diagnosis when part of an ophthalmology record?

• F-06030 (postop status). – Postop status is for the immediate post-op period. Not

for evaluation of the ultimate success or failure of the procedure.

Rechecks

Rule Outs / Differential

• Do not code Rule Out or Differential diagnoses or code them in conjunction with modifier code G-1006. Multiple Rule outs for the same symptoms code at the coder’s discretion. Also, code diagnoses listed as “vs another diagnosis” as rule outs

• When Signs/Symptoms are diagnosed with several Rule outs listed, code the Sign/Symptom independently and then code the Rule out Diagnoses with G-1006.

• Example: Ataxia rule out poisoning or encephalitis. Code Ataxia without the G-code, then code Poisoning and encephalitis with the G code.– VMDB Coding guideline draft (6/20/2001)

Rule Outs / Differential

• Rule-outs / Differential lists SHOULD NOT be coded in a final diagnosis field.

• The structural relationship between signs and symptoms and either individual rule-outs or differential lists cannot be solved through coding schemes alone.

• The medical record system must be structurally capable of managing these relationships.

Suspected

• For Suspected, Possible and Probable diagnoses, code diagnosis in conjunction with the appropriate modifier G code. Diagnoses listed with a “?”, code as Suspected – G-2001.

• Code Signs/Symptoms that are manifested independently without the G code, then code the “suspected diagnoses” with the G code.– VMDB Coding guideline draft (6/20/2001)

Suspected

• Administrative decision again– The secret forms of communication used

between clinicians and medical records personnel are not the purview of this organization…

• ?

• ? Vs ??????

• ;-)

Third Eyelid / Nictitans

• Do not code the diagnosis to conjunctiva. Use topography code T-AA980 for third eyelid of animal (nictitating membrane).– VMDB Coding guideline draft (6/20/2001)

Third Eyelid / Nictitans

• This problem will take care of itself when we create appropriate disorder codes.

• Ophthalmologists are helping with a real nomenclature committee. – Encourage yours to Participate?

Acknowledge? Use?

Warts / Papilloma

• For all warts/papillomas in Bovines, use DE-32A31 and the T-code for the site.

• For all other species, use a D code for benign neoplasm by site; M code for wart or papilloma; T-01747 (Animal skin wart) and G-F505.– VMDB Coding guideline draft (6/20/2001)

Warts / Papilloma

• We need to make sure that Bovine Wart/Papilloma integrates well with others.

What to do…

• VMDB-sponsored nomenclature party.– At Virginia Tech

• Dr. Livesay, Dr. Freeman and I are already there.

• I’d suggest peak fall foliage season!

– Break into 3 – 5 working groups of 2-3 people.• Could invite experts to lead working groups?

– Surgeon, oncologist, cancer registry manager

– Use Virginia Tech tools to create subsets

– Use Virginia Tech tools to create examples