Evaluation of a Proposed Method for Representing Drug Terminology

James J. Cimino, Timothy J. McNamara, Terri Meredith, Carol A. Broverman,

Karen C. Eckert

Drug Terminology Efforts in HL7

• Need for medication terms

• Much source data generated by pharmacy systems

• Pharmacy knowledge base vendors are exploring ways to place their terminologies in the public domain

• Vocabulary TC convened meetings to explore ways of collaborating

Disclaimer

• Nothing is a balloted standard yet

• TC has not yet proposed a formal model

• TC has not yet proposed a plan of action

• TC is still defining scope and goals

Drug Model Hierarchy

Drug Class

Not-Fully-Specified Drug

Clinical Drug

Trademark Drug

Manufactured Components

Ingredient Class

International Package Identifiers

Country-Specific Packaged Product

Ingredient

is-a

is-a

is-a

is-a

is-a

is-a

Chemicals

MedicationsPackages

Composite Clinical Drug

is-a

Composite Trademark Drug

is-a

Drug Model Hierarchy

Drug Class

Not-Fully-Specified Drug

Trademark Drug

Manufactured Components

Ingredient Class

International Package Identifiers

Country-Specific Packaged Product

Ingredient

is-a

is-a

is-a

is-a

is-a

is-a

Chemicals

MedicationsPackages

Composite Clinical Drug

is-a

Composite Trademark Drug

is-a

Clinical Drug

Clinical Drugs

• Dosage form

• Active ingredients– Chemical

– Form Strength• Strength amount

• Strength units

• Volume

• Volume units

Experiment

• Can model allow for interoperability?– Single terminology vs.– Mapping between terminologies

• Select random sample of drug terms

• Obtain descriptions from terminology developers

• Compare description components

• Examine overall match rate

Sample Selection

• 71,000 NDC Codes

• 1000 selected at random (1.4%)

• Many are obsolete

Descriptions from Vendors

Name Form Ingredient 1 Ingredient 2

Valium 5mg Tablet Tablet Diazepam ^5^mg

Tylenol #3 Tablet Acetaminophen Codeine ^325^mg ^30^mg

Chloral Hydrate Syrup Syrup Chloral Hydrate 100.000000^mg^1.000000^ml

Descriptions from Vendors

Set Mapped

A 358

B 459

C 605

D 405

E 566

A B C D E None

- 340 358 326 357 642

340 - 452 361 449 541

358 452 - 393 554 395

326 361 393 - 392 395

357 449 554 392 - 434

Overall, 367 terms were not represented in any set, 71 appeared in only one set, 77 appeared in exactly two sets, 83 appeared in three sets, 91 appeared in four, and 311 terms appeared in all five terminologies.

Pairwise Comparisons

Set B C D E

A 340 358 326 357

B 452 361 449

C 393 554

D 392

E

Pairwise Comparisons

Set B C D E

A 340 358 326 357

B 452 361 449

C 393 554

D 392

E

{3982

Comparisons

• Dosage Form: 3982

• Ingredient (number and match): 5507

• Dose Strength (dose, units, volume, volume units): 4337

• Overall: 3982

Dosage Form Matching

• TAB = TABLET

• LIQUID ORAL LIQUID

• 111 Dosage form synonyms

Ingredient Matching

• HCl vs. Hydrochloride

• Salt vs. Base

• Inclusion of form or route

• Mention of animal source

Dose Strength Matching

• Standard format (000050000 vs. 500.00)

• Normalization of units (GM vs. MG)

Dose Units Matching

• Standard abbreviations

• Normalization of units (GM vs. MG)

• Missing values

• Inclusion of concentration information

• MG vs. %

Dose Volume Matching

• Not given

• Different numeric formats

• Defaults (0 and 1)

• Different volumes ( per 1ml vs per 5ml)

Dose Volume Units Matching

• Not given

• “Each”

• Different abbreviations

Overall Matching

• Form matches

• Same number of ingredients

• Each ingredient matches on chemical and all four other parameters

Overall Matching

Total Before After Conversion Conversion Components: Ingredients 5507 3607 (65%) 4337 (79%) Strength 4337 374 (9%) 3262 (75%) Units 4337 1845 (43%) 2964 (68%) Volume 4337 1054 (24%) 3754 (87%) Volume Units 4337 2319 (53%) 3486 (80%)

Components:

Overall: Each Ingred 4337 0 (0%) 2773 (64%) All Ingred 3982 0 (0%) 2519 (63%) Dose Form 3982 645 (16%) 2859 (72%) Complete Drug 3982 0 (0%) 2128 (53%)53%

Pairwise Comparisons

Set A B C D E

A - 340 358 326 357

B 340 - 452 361 449

C 358 452 - 393 554

D 326 361 393 - 392

E 357 449 554 392 -

Set A B C D E

A - 59% 45% 48% 52%

B 59% - 54% 63% 62%

C 45% 54% - 46% 48%

D 48% 63% 46% - 58%

E 52% 62% 48% 58% -

Pairwise Complete Matches

Example of MismatchGUAIFENESIN AC LIQUID|10;100|MG/5ML;MG/|LIQUID

SYRUP|GUAIFENESIN^00000000.000^^0000.000^CODEINE PHOSPHATE^.^^.^

LIQUID|CODEINE PHOSPHATE^2.000000^MG^^GUAIFENESIN^20.000000^MG^1.000000^ML

LIQUID, ORAL (SYSTEMIC)|CODEINE PHOSPHATE^10^MG^5^MLGUAIFENESIN^100^MG^5^ML

LIQUID|CODEINE PHOSPHATE^10.0000^MG/5ML^^GUAIFENESIN^100.0000^MG/5ML^^

SYRUP|CODEINE PHOSPHATE^10^MILLIGRAM(S)^5^MILLILITER(S)GUAIFENESIN^100^MILLIGRAM(S)^5^MILLILITER(S)

Example of Mismatch

BUMEX INJECTION|0.25|MG|INJ-SOL

AMPUL

BUMETANIDE^00000000.250^MG^0001.000^ML

INJECTION

SODIUM CHLORIDE, IV USE^0.850000^%^^

BUMETANIDE, INJECTABLE^0.250000^MG^1.000000^ML

INJECTION

BUMETANIDE^0.25^MG^1^ML

SOLUTION

BUMETANIDE^0.2500^MG/ML^^

SOLUTION

BUMETANIDE^0.25^MILLIGRAM(S)^1^MILLILITER(S)

Example of Mismatch

RECOMBIVAX HB ADULT FORMULATION INJECTION|10|MCG|INJ-SUS

VIAL

HEPATITIS B VIRUS VACCINE^00000010.000^MCG^0001.000^ML

INJECTION

HEPATITIS B SURFACE ANTIGEN^10.000000^MCG^1.000000^ML

INJECTION

HEPATITIS B VACCINE-RECOMBINANT^10^MCG^1^ML

INJECTION

HEPATITIS B VIRUS VACCINE RECOMBINANT^10.0000^MCG/ML ^^

SOLUTION

HEPATITIS B VACCINE RECOMBINANT^10^MICROGRAM(S)^ 1^MILLILITER(S)

Focus on Dosage Form

• 3982 comparisons

• 111 synonyms

• 72% match rate

• What went wrong?

Examination of Dosage Forms

• Compare use of each form, in each source, with use in other sources for corresponding medications

• Look for irregularities in source

• Look for 100% agreement

• When not 100% agreement, look at hierarchical subsumption

Irregularities in Sources

NDC: 0000153144|FLUORITAB TABLETS CHEWABLE CHERRY|1.1|MG| TAB CHEW|100|BOT:

A:: |FLUORITAB 0.5MG TABLET CHEW^SODIUM FLUORIDE| CHEWABLE TABLET|SODIUM FLUORIDE^00000000.500^MG ^0000.000^

B: |FLUORITAB CHERRY TABS CHEW, 0.5MG|CHEWABLE TABLET| SODIUM FLUORIDE^1.100000^MG^^

C: |SODIUM FLUORIDE CHEW TAB 1.1 MG (0.5MG F)|CHEWABLE TABLET|SODIUM FLUORIDE^1.1000^MG^^

D: ||TABLET|SODIUM FLUORIDE^0.5^MG^^

Near Misses and the Hierarchy

ASodium Fluoride1.1 MGChewable TabletB

C

D

Tablet

ChewableTablet

is-a

is-a

Sodium Fluoride1.1 MGTablet

Irregularities in Sources

NDC: 0000014889|PROPRANOLOL HYDROCHLORIDE EXTENDED RELEASE CAPSULES|80|MG|CAP ER|100|BOT

A: ||CAPSULE CR|PROPRANOLOL HYDROCHLORIDE^80^MG^^

B: |PROPRANOLOL 80MG CAPSULE SA^PROPRANOLOL HCL| CAPSULE CR|PROPRANOLOL HCL^00000080.000^MG^0000.000^

C:: |PROPRANOLOL HCL CAP CR 80 MG|CAPSULE CR| PROPRANOLOL HYDROCHLORIDE^80.0000^MG^^

D:: |PROPRANOLOL HYDROCHLORIDE^80 MG|CAPSULE CR| PROPRANOLOL HYDROCHLORIDE^80^MILLIGRAM(S)^1^EACH

E:: |PROPRANOLOL HCL TABS CR, 80MG|TABLET CR|PROPRANOLOL HYDROCHLORIDE^80.000000^MG^^

Example of 100% Agreement

A: LOTION: 1: LOTION|

B: LOTION: 1: LOTION|

C: LOTION: 1: LOTION|

D: LOTION: 1: LOTION|

E: LOTION: 1: LOTION|

Example of 100% Agreement

A: TABLET CR: 14: TAB E REL|TAB FC ER

B: TABLET CR: 6: TAB FC ER|TAB SUG CO|

C: TABLET CR: 9: TAB FC ER|TAB E REL|

D: TABLET CR: 14: TAB E REL|TAB FC ER|TAB FC|

E: TABLET CR: 7: TAB FC ER|TAB E REL|

Example of <100% Agreement

A: AEROSOL: 2: INHALANT|AEROSL SPR|

B: AEROSOL: 1: INHALANT|

C: AEROSOL: 1: INHALANT| SPRAY, TOPICAL, DERMAL: 1: AEROSL SPR|

D: AEROSOL: 2: INHALANT|AEROSL SPR|

E: AEROSOL: 1: INHALANT|

Handling Ambiguity

Aerosol

InhaledAerosol

is-a

DermalAerosol

A

Triamcinolone Acetonide0.147mg/GMAerosol

A

Terbutaline Sulfate0.2mg/ACTAerosol

D

Terbutaline Sulfate0.2mg/ACTInhaled Aerosol

C

E

B

C

Triamcinolone Acetonide0.147mg/GMDermal Aerosol

is-a is-a

Example of Subsumption

Aerosol ():A(AEROSOL) D(AEROSOL)

Inhaled Aerosol (INHALENT):B(AEROSOL) C(AEROSOL)

E(AEROSOL)

Dermal Aerosol (AEROSL SPR): C(SPRAY TOPICAL, DERMAL)

No Solution for SolutionAMPULDROPSINFUS. BTLINJECTIONIRRIGATION SOLUTIONIV SOLN.KITPIGGYBACKPLAST. BAGSKIN TESTSOLUTIONSYRUPVIAL

ELIXIRINJ REPOSITORYINJECTIONINJECTION TYPEINJECTION IVPBKITLIQUIDSOLUTIONSUSPENSION

DROPS, OPHTHALMIC (NON-SYSTEMIC)INJECTIONIRRIGATION SOLUTIONKIT, INJECTION (SYSTEMIC)SOLUTION FOR DROPS, OTICSOLUTION FOR INHALATION...SOLUTION OPHTMALMIC…SOLUTION, ORAL (SYSTEMIC)SOLUTION, OTICSOLUTION, TOPICAL, DERMALSYRUP

CONCENTRATEINJECTIONKITNEBUOILSOLUTIONSYRUP

Discussion

• Matching is still far from perfect

• Not surprising, given lack of standards for attribute values

• Next steps

Discussion: Next Steps

• Define some rules for each field

• Select new random sample

• Find subset with good overlap across terminologies

• Submit descriptions of new subset

Discussion: New Rules

• Dose forms: separate translation step• Ingredients:

– Right number– Specific chemical entity– Identifiers (UMLS?)– Don’t mix in route or concentration

• Strengths:– Conversion algorithms– Rules for defaults– Don’t mix route or concentration with strength

Conclusions

• Glass half empty:– How can we do automated translation of patient

data?– Can drug order transfers and decision support

be safe?

• Glass half full:– No attempt yet to standardize attribute

terminology– Most translation was much better than 50%– Just getting started– Better than what we do now