Abstract. The Virtual Medical Record (vMR) is a structured data model for representing individual patient informations1. Our implementation of vMR is based.
Implementation of Virtual Medical Record Object Model for a Standards-Based Clinical Decision Support Rule Engine Christine Huanga, MS, Laura A. Noirotb, BS, Kevin M. Hearda, BS, Richard M. Reichleya, RPh, Wm Claiborne Dunagana,b, MD, and Thomas C. Baileya,b, MD From aBJC HealthCare and bWashington University School of Medicine, St. Louis, Missouri vMR is used in our rule representation format for Abstract patient data query and expression evaluation. For The Virtual Medical Record (vMR) is a structured example, an XPath expression to check whether a data model for representing individual patient patient’s last LDL test was greater than 100 will be informations1. Our implementation of vMR is based written as: on HL7 Reference Information Model (RIM) v2.13 /vmr/observation[./codeValue=][last()] > 100 from which a minimum set of objects and attributes Therefore, the encoded rule does not need to refer to are selected to meet the requirement of a clinical any institution-specific database field or object decision support (CDS) rule engine. Our success of attribute. mapping local patient data to the vMR model and Results building a vMR adaptor middle layer demonstrate the In the local CIS for BJC HealthCare, rule relevant feasibility and advantages of implementing a vMR in patient data from more than ten tables in a relational a portable CDS solution. database were successfully mapped to the vMR. Figure 1 shows that a vMR adaptor is a middle layer Introduction between CDS rule engine and its clients. The rule Numerous successes have been reported using service clients A and B can be hosted in different automated CDS to improve the quality of patient institutions, written in different languages, running care. However, most of these solutions were on different platforms. As long as their local institution specific. Facing the reality of implementation of vMR adaptor can generate the heterogeneity of local CIS, recent technologies such vMR format known to the rule engine, they can share as GLIF and SAGE adopted the approach of using a the rule base and decision support service provided vMR to standardize the data interface between CDS by the rule engine. applications and a local CIS. While a standard vMR specification is not yet established, there is consensus Figure 1. Use of vMR in CDS Rule Engine. building for use of HL7 RIM.1
Methods We implemented a VMR as a simplified view of HL7 RIM v2.13. A minimum set of objects and attributes that were relevant to our CDS rule set was selected as shown in Table 1. We added a CDSAction object for modeling CDS assessment specification and state. It is a subclass of Act with unique attributes such as rule identifier and message destination. Table 1. Objects in vMR Objects RIM objects Person Entity/Person PatientEncounter Act/Patient_Encounter Observation Act/Observation Substance Act/Substance_Administration Administration Procedure Act/Procedure CDSAction The data types to encode object attributes in the vMR were based on the HL7 RIM. They meet the requirement to encode character, numeric, or temporal data. They will also facilitate knowledge management with built-in support for different coding systems and versions.
Conclusions Implementation of vMR will eliminate the dependency on local data models and vocabularies to facilitate a portable CDS solution. Reference [1] Peter DJ, et al. A Virtual Medical Record for Guideline-Based Decision Support. Proc AMIA Symp. 2001 Supported by NHLBI Grant R01 HL70790-01A1.
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