Background
Clinical decision support such as alerts, reminders and guidance are driven by rules often distributed among a variety of applications in a healthcare information system. Due to the increasing size of rule bases, there is a growing need to manage this dispersed knowledge in an integrated environment1. A system for management of executable clinical knowledge such as rules should (1) assist in the development and maintenance of rules throughout the rules’ life-cycles, (2) support search and retrieval of rules in the knowledge base (e.g., rules for diabetes, rules created by a particular individual), and (3) facilitate the analyses of rules in the knowledge base (e.g., identify rules not updated in the last year).
In order to create such a clinical knowledge management system it is necessary to model the meta-data of rules. There have been efforts to document meta-data about rules within the Arden Syntax Medical Logical Modules’ project. However, the maintenance and library categories in that project allow mainly free-text information about a rule 2. We have created a comprehensive meta-data structure and taxonomy for describing clinical rules that supports the features of a knowledge management system. We also tested this model using a representative set of rules.
Methods
The model that we developed is informed by knowledge bases used by applications providing clinical decision support at the Brigham and Women’s Hospital (BWH), which is a tertiary care academic hospital. The rules in these knowledge bases are encoded in local formats and have evolved over several years3. We conducted a comprehensive inventory and analysis of the existing knowledge bases in use at BWH. Based on this inventory, a survey of literature and an analysis of needs of a knowledge management system, we developed a comprehensive meta-data structure and taxonomy to describe the rules in the knowledge base. We developed an MS-ACCESS database using the meta-data structure as the data model for the rules. We tested the model by sampling 50 rules from the various decision support systems and entering their meta-data in this database.
Results
The meta-data model consists of the descriptors listed in the following table. The relational database schema reflecting this model contains 9 tables. The central “RULES” table contains fields that describe the main characteristics of a rule including-Implementation date, Target setting, Purpose (efficiency, quality) and Category (values from the National Clearinghouse Guideline’s Category concepts). The other 8 tables that represent the axes of the taxonomy are:
| Table | Principal Attributes |
|---|---|
| Authors | personal details, role, expertise |
| Editors | rule and editor ID’s |
| Evidence basis | details about the evidence and the local modifications |
| Implementation | the interface application and the event that evoked the rule |
| Revision history | date, author and revision content |
| Usage | data about counts/year, behavioral change and cost reduction |
| Users | user types – hospital physician, PCP, Nurse etc. |
| Keywords | UMLS concepts |
We developed forms for easy entry and retrieval of rule information. We also developed a series of pre-formulated queries and forms that fulfill what we expect would be commonly requested demands for information from the knowledge management system.
Discussion
Testing of the system with 50 rules enabled us to refine the meta-data model and the taxonomy. We believe that this model can serve as a prototype to handle problems in managing knowledge in decision support systems. A more formal evaluation of the model should be conducted.
References
- 1.Jenders RA, Huang H, Hripcsak G, Clayton PD. Evolution of knowledge base for clinical decision support system encoded in the Arden Syntax. Proc AMIA Symp. 1998:558–62. [PMC free article] [PubMed] [Google Scholar]
- 2.Pryor TA, Hripcsak G. The Arden syntax for medical logic modules. Int J Clin Monit Comput. 1993;10(4):215–24. doi: 10.1007/BF01133012. [DOI] [PubMed] [Google Scholar]
- 3.Kuperman GJ, Teich J, Gandhi TK, Bates DW. Patient safety and computerized medication ordering at Brigham and Women’s Hospital. Journal on quality improvement. 2001;27(10):509–21. doi: 10.1016/s1070-3241(01)27045-x. [DOI] [PubMed] [Google Scholar]