DR ANTHONY MADDEN Consultant Anaesthetist

& ACIS Programme DirectorNorth Bristol NHS Trust

CLINICAL DECISION SUPPORT AND

PROGRAMMING IN ARDEN SYNTAX

• to explain the term ‘Clinical Decision Support' in the context of EPR/EHR

• to explain why we need CDS

• to explain what Arden Syntax is

• to introduce programming medical logic modules in Arden Syntax

AIMS

• Clinical Decision Support

• Why we need CDS

• Arden Syntax

• Programming ‘medical logic modules’ in Arden Syntax

CLINICAL DECISION SUPPORTCLINICAL DECISION SUPPORT

“Pull Technology”•Medline•Embase•NELH• Internet•WeBNF

CLINICAL DECISION SUPPORTCLINICAL DECISION SUPPORT

“Push Technology”•Notes•Order sets•Care pathways•Expert systems

•Arden Syntax

• Clinical Decision Support

• Why we need CDS

• Arden Syntax

• Programming ‘medical logic modules’ in Arden Syntax

CLINICIANS NEED INFORMATION AT THE POINT OF

CARE

“If we managed travel like we manage healthcare then travel agents would book flights on the basis of the flight schedules they could remember"

Lawrence L WeedLawrence L Weed

HOSPITAL FATALITY HOSPITAL FATALITY RATERATE

“In the USA medical error results in 44,000-98,000 unnecessary deaths each year and 1,000,000 excess injuries”

Epidemiology of medical errorBMJ 18 March 2000

EFFECTIVENESS OF CDSSEFFECTIVENESS OF CDSS

Perioperative Antibiotic Administration

• Intervention : reminder re timing and type of antibiotic

• Period : 1988 - 1994• Result : perioperative wound infections

declined from 1.8% to 0.9%• average # doses : 19 to 5.3• antibiotic cost per patient: $123 to $52(Pestotnik, LDS Hospital: Ann Intern Med 1996;124(10):884-90)

• Clinical Decision Support

• Why we need CDS

• Arden Syntax

• Programming ‘medical logic modules’ in Arden Syntax

MEDICAL LOGIC MODULEMEDICAL LOGIC MODULEMEDICAL LOGIC MODULEMEDICAL LOGIC MODULE

• Each MLM contains maintenance information, links to other sources of knowledge, and enough logic to make a single health decision

• The Medical Logic Module (MLM) is a stream of text stored in an ASCII file in statements called slots

ARDEN SYNTAX - DEFINITION

ARDEN SYNTAX - DEFINITION

Arden Syntax is an HL7/ANSI standard specification for defining and sharing medical logic. It is a programming language.

Current approved version is 2.1

ARDEN SYNTAX - HISTORYARDEN SYNTAX - HISTORYARDEN SYNTAX - HISTORYARDEN SYNTAX - HISTORY

HELPLDS Hospital

Salt Lake City, UT

CARERegenstrief Institute

Indianapolis, IN

Arden Syntax

Retreat at Arden Homestead, Harriman, NY 1989

Arden SyntaxArden Syntax

• Version 1: 1992 ASTM document 1460

• Version 2: 1999 HL7/ANSI• Version 2.1 : 2002 HL7/ANSI

SUPPORT FOR ARDEN SUPPORT FOR ARDEN SYNTAXSYNTAX

• Eclipsys / iSoft

• McKessonHBOC

• Siemens

• Cerner

• IBM

• SMS

• Epic Systems

• Micromedex

Arden: New InitiativesArden: New Initiatives

• Structured Write statement: - XML DTD

• Representing MLMs in XML

• Data Model: Fuzzy logic, standard expression language, etc

• Clinical Decision Support

• Why we need CDS

• Arden Syntax

• Programming ‘medical logic modules’ in Arden Syntax

MLM - StructureMLM - StructureMLM - StructureMLM - Structure

Categories & Slots maintenance:

slotname: slot-body;;

library:slotname: slot-body;;

knowledge:slotname: slot-body;;

end:

Maintenance Category Slots Maintenance Category Slots (9(9))

Maintenance Category Slots Maintenance Category Slots (9(9))

•Title•Mlmname (formerly called filename)

•Arden•Version• Institution•Author•Specialist•Date•Validation

Library Category Slots (5)Library Category Slots (5)Library Category Slots (5)Library Category Slots (5)

• Purpose • Explanation• Keywords• Citations (optional)• Links (optional)

Knowledge Category Slots Knowledge Category Slots (7)(7)

Knowledge Category Slots Knowledge Category Slots (7)(7)

•Type•Data*•Priority•Evoke•Logic*•Action•Urgency

Data SlotData SlotData SlotData Slot

•Terms in the medical logic module must be mapped to a database

•Use of curly braces { } allows flexibility in mapping to the institution’s local database

•Mapping terms in this way separates the logic in the MLM from institution-specific information

Logic SlotLogic SlotLogic SlotLogic Slot

• Logical algorithm ‘If…….then…..’

• Ends with a “conclude statement”

conclude true; orconclude false;

Conclude StatementConclude StatementConclude StatementConclude Statement

• conclude true;

terminates the rule go to the action slot

• conclude false;

terminates the rule do not go to the action slotgo to end;;

PLAYTIME!PLAYTIME!