medexter clinical decision support

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1 Arden Syntax overview Educational material, part 2 (of 5) Medexter Healthcare Borschkegasse 7/5 A-1090 Vienna (academic) Better care, patient safety, and quality assurance by Medexter, Vienna, Austria

2 Arden Syntax: HL7- and ANSI-approved A standard language for writing situation-action rules, procedures, or knowledge bases that trigger results based on clinical events detected in patient data Each module, referred to as a medical logic module (MLM), contains sufficient knowledge to make at least a single medical decision extended by medical knowledge packages (MKPs) consisting of interconnected MLMs for complex continuous development since 1989 The Health Level Seven Arden Syntax for Medical Logic Systems, version 2.9 including fuzzy methodologies was approved by Health Level Seven (HL7) International and the American National Standards Institute (ANSI) in 2013 Version 2.10 including ArdenML, an XML-based representation of Arden Syntax MLMs was approved in 2014 healthcare industry and academic users

3 What is Arden Syntax? a knowledge representation standard primarily meant for medical knowledge. used for sharing computerized health knowledge bases across personnel, information systems, and institutions. organized in modules. Each module is referred to as a medical logic module (MLM) and contains sufficient knowledge to make at least a single medical decision. a computer-interpretable format that is used by systems.

4 History 1989: A first draft of the standard was prepared at a meeting at the Arden Homestead, New York. Arden Syntax was subsequently adopted as a standard by the American Society for Testing and Materials (ASTM) as document E 1460, under subcommittee E Health Knowledge Representation. 1992: Arden Syntax version : sponsorship moved to HL7 International (Arden Syntax Work Group) 1999: Arden Syntax version 2.0 approved by HL7 and the American National Standards Institute (ANSI) 2014: Arden Syntax version 2.10 Continuous development

5 History Version Year Important changes new string operators; reserved word currenttime returns the system time object capabilities: create and edit objects; XML representation of MLMs (except logic, action and data slot) UNICODE encoding; additional resources category to define text resources for specific languages; time-of-day and day-of-week data types; localized operator to access texts in specific languages enhanced assignment statement; extended new operator to allow easy and flexible object instantiation additional operators for list manipulation; operators to manipulate parts of given date and time values; switch statements; keyword breakloop for aborting a loop; number of editorial corrections Fuzzy: fuzzy data types, fuzzy sets, and fuzzy logic; adjustment of all available operators to be able to handle fuzzy data types XML representation of MLMs (including logic, action and data slot)

6 Arden Syntax Structure In Arden Syntax, medical knowledge is hierarchically arranged within medical logic modules (MLMs) Each MLM represents sufficient knowledge to make at least one single medical decision An MLM is stored in a file that has the file extension.mlm Each MLM is well organized and structured into categories and slots. Categories must appear in a predefined order. Each category contains a category-specific set of slots, also in a predefined order.

7 Lotfi From: Dupré, B. The sorites paradox. In Dupré B. (2007) 50 philosophy ideas you really need to know. Quercus Publishing PLc, London, p. 122.

8 Fuzzy Arden Syntax: Modelling uncertainty in medicine linguistic uncertainty due to the unsharpness (fuzziness) of boundaries in linguistic concepts; gradual transition from one concept to another modeled by fuzzy sets (e.g., fever, increased glucose level, hypoxemia) propositional uncertainty due to the incompleteness of medical conclusions; uncertainty in definitional, causal, statistical, and heuristic relationships here: modeled by truth values between zero and one (e.g., 0.6, 0.9)

9 Arden Syntax MLM - Maintenance Category Purpose: To provide general information on the MLM, unrelated to the MLM s medical knowledge Used for MLM knowledge base maintenance and version control Slots (bold means required): title: Title of the MLM mlmname: Name as referred to by the host system; must have the extension.mlm arden: Arden Syntax version version: MLM version institution: Institution which created / adopted the MLM author: Author / implementer of the MLM specialist: Medical specialist supervising the MLM s medical content date: Date of creation / last update validation: The MLM s current status: production, research, testing, or expired MLMname, institution, and MLM version are used to identify the MLM 9

10 Arden Syntax MLM - Maintenance Category - Example 10

11 Arden Syntax MLM - Library Category Purpose: Meant to provide medical background information about the MLM Contains slots pertinent to maintenance activities related to the MLM s medical knowledge Slots: purpose: This slot describes the clinical aim of the MLM. explanation: Description on how the MLM works. keywords: Keywords are descriptive words used for searching through modules. Keywords are delimited by semicolons. citations: Citations allow for the documentation of references to relevant used literature. links: This slot allows for providing links to sources of information relevant for this MLM (e.g., electronic textbook, teaching cases, web resources) 11

12 Arden Syntax MLM - Library Category - Example 12

13 Arden Syntax MLM - Knowledge Category Purpose: Contains the slots that actually specify what the MLM does. Used for data acquisition and for programming the CDS logic / algorithm. Slots (bold means required): type: Only data_driven is available! data: Here, variables locally used in the MLM are mapped to variables at the healthcare institution. priority: Indicates the relative order in which MLMs should be evoked. evoke: The conditions at which the MLM is activated. logic: The actual programmed CDS logic / algorithm. action: Specifies the action taken when the logic slot concludes true urgency: The importance of the action when the MLM concludes true. 13

14 Arden Syntax MLM Knowledge Category Example SIRS Notification ALERT if 2 Criteria Temperature > 38 C (100.4 F) or < 36 C (96.8 F) and/or Heart rate > 90 beats per minute and/or Respiratory rate > 20 breaths per minute or arterial carbon dioxide tension (PaCO2) < 32 mm Hg and/or White blood cell count (>12,000/µL or < 4,000/µL or >10% immature [band] forms) SIRS: systemic inflammatory response syndrome

15 Arden Syntax MLM - Resources Category Purpose: Allows for defining localized, different language messages. Specify the textual resources from which the localized messages are taken. The Resources Category is optional. If no category is provided, Slots: default: Defines the default language to be used language: one language slot for each language to be used. Language codes are defined either as 2-character ISO language codes or as combination of a 2-character ISO language code and a 2- character ISO geographical code. 15

16 Arden Syntax MLM - Resources Category - Example Example: resources: default: en;; language: en SIRS': Alert: The patient shows signs of SIRS"; ;; 16

17 Arden Syntax MLM Host system interaction To start the execution of an MLM, an engine is needed that handles communication with the host system and can tell which of the MLMs is available Ways to start running an MLM: MLM call: An MLM is directly called Event call: An MLM that listens to a specific event and becomes notified by the host system is executed 17

18 Arden Syntax MLM Host system interaction - Example Ways to start running an MLM: MLM call: Event call: 18

19 Arden Syntax MLM Host system interaction MLMs are working in close contact with their host system. Ways of interaction are: Input: An MLM can be called together with a list of defined input parameters Curly Braces Expressions: Curly braces expressions implement a special kind of dynamic interaction between MLMs and host systems Write Statements: data can be written / sent to destinations that are maintained by the host system Output: Analogous to input parameters, data can be sent from the MLM to the host system after execution of the MLM has finished 19

20 Arden Syntax MLM Input and Curly Braces Example Input: Curly Braces: 20

21 Arden Syntax MLM Write Statements and Output Example Write Statements: Output: 21

22 Arden-Syntax-based CDS authoring tool and engine being examined: Camunda BPMN data platforms and warehouses CDS Hooks and clinical microservices

23 Types of integration I. MLM/event calls together with data through web services II. MLM/event calls through web services data access from inside MLMs through connectors as + {SQL} + {FHIR} + {web services} + { } III. Data warehouse + ArdenSuite server = autonomous CDS system data provided through HL7/XML/batch/ communication full process control (MLM triggering) additional analytics, reporting, benchmarking full legal control (legal obligation to retain data, burden of proof)