Vive la différence? Dose Vs Product Dose instructions syntax Dr Paul Miller [email protected]

Vive la différence?

Dose Vs ProductDose instructions syntax

Dr Paul [email protected]

Prescribing Model

Dose Based

Hospital / Secondary Care

La différence…

Furosemide 80mg oral at 8am

General Practice / Primary Care

Product based

Furosemide 40mg tablets , take 2 at 8am

InterfaceFurosemide 80mg oral at

8am

Furosemide 40mg tablets, take 2 at 8am

dm+d

VMPVirtual

MedicinalProduct

VMPPVirtual

MedicinalProduct Pack

AMPPActual

MedicinalProduct Pack

AMPActual

MedicinalProduct

VTMVirtual

TherapeuticMoiety

Atenolol 50mg

tablets

Atenolol 50mg

tablets x28

Atenolol 50mg

tablets (Cox) x28

Virtual Product Ingredient

Controlled Drug Prescribing

Combination Pack Content

Drug Tariff Category

Pack Price

Reimbursement Information

Appliance Product

Information

Product Prescribing

Atenolol 50mg

tablets (Cox)

Actual Product Excipient

Product Availability

Atenolol

Virtual Product Form

Virtual Product Route Supplier

Licensed Route

Furosemide 80mg oral at

8am

FurosemideFurosemide

40mg tablets take 2 at 8am

Furosemide 40mg tablets

Solve this with?

• Models of dose & directions – ‘dose syntax’• Would allow calculation of e.g.

– Daily quantities– Compliance– Safety– Dose comparison

• Translation of– Dose to Product– Product to Dose

Model of dose and frequency

• Dose– 40mg– 0.5mcg– 5ml– 2 tablets– Thinly– 2 puffs qds– If Systolic >160 take

80mg

• Frequency– Daily– Three times a day– Once daily at 18:00– Every Wednesday– Reducing by 1 tab a

week to zeroComplex!

Work to date…2005

2008

Dose Syntax Project

• …all dosage instructions require human reading and interpretation and transcription between different systems, both of which offer a variety of opportunity for patient critical error to enter

Dose Syntax Project

• Therefore, having a representation of dosage instructions in a format to support electronic use is a key requirement to move forward in such areas as automated data entry into prescription

• Many systems have local vocabularies to produce dosage instructions ; however these are non -standard in both content and structure

Vision ‘vocabulary’ example

Dose Syntax Project

• Core Components– dose quantity– timing of the dosage– route, site and method of administration – rate of administration– “additional information”

• (e.g. swallow whole, on an empty stomach).

Dose Syntax Class Model

In HL7 V3 Pharmacy Model

Issues

• Dose / Quantity– Reducing doses– mg/kg

• Timing Issues– ‘during waking hours’– ‘except Mondays and Fridays’

• Modelling issues– “0.5 initially. If no joy, take 1 next time. Again if

not successful take 2 next time”

NHS CFH Dose Syntax Abstract Model

• “The Dose Syntax Abstract Model is intended to be independent of any technology standard or software platform and has been developed with the aim of specifying the necessary clinical requirements precisely and unambiguously”

NHS CFH Dose Syntax Abstract Model

• Dose Comparison• Dose Conversion• Dose/Volume Calculations• Dose Range Checking• Ward Medicines Management• Usage within Primary Care• Dosage Presentation

Medication Administrationclass Medication Administration Package

EA 7.1 Unregistered Trial Version EA 7.1 Unregistered Trial Version EA 7.1 Unregistered Trial Version EA 7.1 Unregistered Trial Version EA 7.1 Unregistered Trial Version EA 7.1 Unregistered Trial Version EA 7.1 Unregistered Trial Version EA 7.1 Unregistered Trial Version





































Medication Administration

Precondition

- preconditionType: Coded- offset: DurationInterval [0..1]

Additional Instructions

- description: String

Dose String

-/ doseString: String

Medication Administration Instruction

- administrationDetails: String [0..1]

Described Medication

Medication

Dose Quantitie s

Medication Dose Timing

Medication Dose Rate

Medication Dose Quantity

Medication Administration Procedure

- route: Coded [0..1]- administrationSite: Coded [0..*]- excludedAdministrationSite: Coded [0..*]- method: Coded [0..*]

Event Criterion

Goa l

- goalType: Coded

Ev ent Criterion Reference

- value: Reference

Coded Ev ent Criterion

- value: Coded

1..1

+additionalInstructions

0..*

1.. *

+doseTiming

1..1

1..1

+doseString 1..1

1..1

+doseQuantity

0..10..*

+medication

0..1

1..1

+doseRate

0..1

0..*

+criterion 0..1

0..*

+objective 0..1

1..1

+administrationProcedure 0..*

…contains the set of classes, and their relationships and constraints required to describe the administration of a medication

Described Medicationclass Described Medication Package

EA 7.1 Unregistered Trial Version EA 7.1 Unregistered Trial Version EA 7.1 Unregistered Trial Version EA 7.1 Unregistered Trial Version EA 7.1 Unregistered Trial Version EA 7.1 Unregistered Trial Version

































Medication

- medicationId: Coded- form: Coded [0..1]- brand: Coded [0..1]

Ingredient

- ingredientSubstanceId: Coded


Ingredient Strength Component

- value: Real- unitOfMeasure: Coded [0..1]

Dose Form Size

- value: Real- unitOfMeasure: Coded [0..1]

1..1

+doseFormSize 0..1

1..1

+strengthNumerator 1..1

0..*

+medication

0..1

1..1

+strengthDenominator 0..1

1..1

+/ingredient

0..*

…the set of classes, and their relationships and constraints that represent aspects of a medication item relevant to specifying a structured Medication Administration Instruction.

Dose Quantitiesclass Dose Quantities PackageEA 7.1 Unregistered Trial Version EA 7.1 Unregistered Trial Version EA 7.1 Unregistered Trial Version EA 7.1 Unregistered Trial Version EA 7.1 Unregistered Trial Version EA 7.1 Unregistered Trial Version EA 7.1 Unregistered Trial Version EA 7.1 Unregistered Trial Version








































Dose Quantitie s


- intention: String- doseTime: Timestamp [0..*] {ordered}



Medication Dose Quantity Ratio


Medication Unit Dose Quantity

- value: RealInterval- unitOfMeasure: Coded- unitOfMeasureType: Coded

Time Period

- value: DurationInterval


- value: RealInterval- unitOfRate: Coded- unitOfMeasureType: Coded

Medication Dose Interv al

- alignment: Coded [0..1]

Medication Dose Frequency

Medication Dose Occurrence

- value: IntegerInterval

Simple Dose Frequenc y

Complex Dose Frequency

- alignment: Coded [0..1]

Inner Timing

1..1

+dosePeriod 1..1

1..1

+periodicInterval

1..1

1..1

+doseRate

0..1

1..1

+doseQuantity

0..1

1.. *

+doseTiming

1..1

0..1

+numerator 1..1

1..1

+doseInterval 1..1

1..1

+courseDuration 0..1

0..1

+numberOfDoses

1..1

1..1

+doseDuration 0..*

1..1

+dosePeriod

1..1

1..1

+innerTiming 1.. *

0..1

+denominator 1..1

…represent the key physical quantity attributes of dose quantity, dose timing and, for continuously administered medications, dose duration and dose rate…

Together…class NHS Dose Syntax Model

EA 7.1 Unregistered Trial Version EA 7.1 Unregistered Trial Version EA 7.1 Unregistered Trial Version EA 7.1 Unregistered Trial Version EA 7.1 Unregistered Trial Version EA 7.1 Unregistered Trial Version EA 7.1 Unregistered Trial Version EA 7.1 Unregistered Trial Version EA 7.1 Unregistered Trial Version EA 7.1 Unregistered Trial Version EA 7.1 Unregistered Trial Version

















































Precondition

Additional Instructions

Dose String


Medication Administration Procedure

Event Criterion

Goa l

Ev ent Criterion ReferenceCoded Ev ent Criterion


Medication Ingredient

Ingredient Strength ComponentDose Form Size

Dose Quantitie s


Medication Dose Quantity Ratio


Medication Unit Dose Quantity

Time Period


Medication Dose Interv al

Medication Dose Frequency

Medication Dose Occurrence

Simple Dose Frequenc y

Complex Dose Frequency

Inner Timing

1..1

+additionalInstructions

0..*

1..1

+doseString 1..1

1..1

+administrationProcedure 0..*

0..*

+criterion 0..1

0..*

+objective 0..1

0..*

+medication

0..1 1..1

+/ingredient

0..*

1..1

+strengthNumerator 1..1

1..1

+strengthDenominator 0..1

1..1

+doseFormSize 0..1

1.. *

+doseTiming

1..1

1..1

+doseQuantity

0..1 0..1

+numerator 1..1

0..1

+denominator 1..1

1..1

+courseDuration 0..1

1..1

+doseDuration 0..*

1..1

+doseRate

0..1

1..1

+periodicInterval

1..1

1..1

+dosePeriod

1..1

0..1

+numberOfDoses

1..1

1..1

+doseInterval 1..1

1..1

+dosePeriod 1..1

1..1

+innerTiming 1.. *

Dosage Calculations

• Dose Syntax Model:– dose conversion calculations;– dose / volume calculations; and– dose rate calculations

• …to be able to convert VTM or product-based dose quantities … into equivalent product-based quantities

• …handling medications and prescriptions between primary and secondary care.

• Discharge medication instructions…converted into product-based quantities.

Using this!

Complex!

Example 45:

During an in-patient stay, a patient is given Atenolol 75 mg daily basis. When the patient is discharged, the discharge instructions to the GP ask for the patient to remain on Atenolol 75 mg daily until the GP is satisfied with the patient’s condition. If the GP wants to prescribe 318434003|Atenolol 25mg tablets|, how many tablets should be taken daily?

Example 45doseInstruction

medication

medicationId 87652004|Atenolol|form 3319411000001109|tablet| doseQuantity

value 75unitOfMeasure 258684004|mg|unitOfMeasureType IQU (ingredient qty unit)administrationProcedure

route 26643006|oral|

Example 45

So.. why not?

• Still some issues– 29 noted

• Basic problems to solve first• Implementation challenges

– Complexity– User interfaces– Safety– Terminologies

• But one day soon…

Summary

• My ‘tds’ is not your 8:00; 14:00; 18:00• Patients swallow products• Prescribers advise doses• The interface needs a brain• Solvable problem

– But Complex!

Documents

Vive la différence? Dose Vs Product Dose instructions syntax Dr Paul Miller [email protected]