THE GUIDELINE INTERCHANGE FORMAT - A MODEL FOR REPRESENTING GUIDELINES

Objective: To allow exchange of clinical practice guidelines among ins titutions and computer-based applications. Design: The Guideline Inter change Format (GLIF) specification consists of the GLIF model and the GLIF syntax. The GLIF model is an object-oriented representation that consists of a set of classes for guideline entities, attributes for th ose classes, and data types for the attribute values. The GLIF syntax specifies the format of the test file that contains the encoding. Meth ods: Researchers from the InterMed Collaboratory at Columbia Universit y, Harvard University (Brigham and Women's Hospital and Massachusetts General Hospital), and Stanford University analyzed four existing guid eline systems to derive a set of requirements for guideline representa tion. The GLIF specification is a consensus representation developed t hrough a brainstorming process. Four clinical guidelines were encoded in GLIF to assess its expressivity and to study the variability that o ccurs when two people from different sites encode the same guideline. Results: The encoders reported that GLIF was adequately expressive. A comparison of the encodings revealed substantial variability. Conclusi on: GLIF was sufficient to model the guidelines for the four condition s that were examined. GLIF needs improvement in standard representatio n of medical concepts, criterion logic, temporal information, and unce rtainty.