The GELLO Expression Language was started in 2001 and introduced in 2002; in 2005, GELLO was adopted as an international standard by

Health Level Seven International Health Level Seven International (HL7) is a Nonprofit organization, non-profit ANSI-accredited standards development organization that develops standards that provide for global health data interoperability. The 2.x versions of the standards a ...

and ANSI for a decision support language. GELLO Release 2 was completed and approved by ANSI in June 2010. The GELLO specifications have been developed in coordination with the HL7 Clinical Decision Support TC (CDSTC). As of 2021, the GELLO Implementation Guide DSTU was withdrawn from HL7 Version 3 due to inactivity. However, Release 2 of the standard remains as is, despite a low level of use. GELLO is a class-based

object-oriented programming language Object-oriented programming (OOP) is a programming paradigm based on the concept of '' objects''. Objects can contain data (called fields, attributes or properties) and have actions they can perform (called procedures or methods and impleme ...

and a relative of the

Object Constraint Language The Object Constraint Language (OCL) is a declarative language describing rules applying to Unified Modeling Language (UML) models developed at IBM and is now part of the UML standard. Initially, OCL was merely a formal specification language ext ...

(OCL). OCL is a well-developed constraint language that makes it attractive for use as an expression language. The intention was for GELLO to evolve as a standard query and expression language for decision support. GELLO creates the potential for many decision support options, as the full array of atomic patient data is greatly accessible to complement better, safer clinical decision-making by health professionals. Furthermore, this enables specialist clinicians to customize their current systems and create flexible purpose built

decision support system A decision support system (DSS) is an information system that supports business or organizational decision-making activities. DSSs serve the management, operations and planning levels of an organization (usually mid and higher management) and ...

s. Standardization of GELLO has made this language compatible with the HL7 version 3.0 Reference Information Model (RIM). GELLO uses an abstract "virtual medical record" (vMR) so that the same GELLO code can run on multiple systems accessing data stored in different formats. The vMR is a simplified view of the HL7 RIM. The 2019 focus of the HL7 CDS WG was to build the Clinical Quality Language (CQL), version 1.5 of which was later published in 2020.

Uses for GELLO

The GELLO language can be used to: * Build up queries to extract and manipulate data from

medical record The terms medical record, health record and medical chart are used somewhat interchangeably to describe the systematic documentation of a single patient's medical history and health care, care across time within one particular health care provide ...

s. * Construct decision criteria by building up expressions to reason about particular data features/values. These criteria can be used in decision-support knowledge bases such as those designed to provide alerts and reminders, guidelines, or other decision rules. * Create expressions, formulae, and queries for other applications. * GELLO was used with Guideline Interchange Format (GLIF), as it is the most expressive expression language in the context of GLIF.{{cite journal, last=Wfirst=A, authorlink2=Dean F. Sittig, author2=Sittig, D, title=A framework and model for evaluating clinical decision support architectures, journal=Journal of Biomedical Informatics, date=2008, volume=41, issue=6, pages=982–990, doi=10.1016/j.jbi.2008.03.009, pmc=2638589, pmid=18462999

References

Object-oriented programming languages

Uses for GELLO

See also

References