Name: Shilpashree Srinivasamurthy
Subject: ACS 560 Software Engineering
Paper 2: Representing Clinical Guidelines in UML: A Comparative Study
Advisor: Dr. John Tanik
Date: 10/22/2010
This paper explores the overlap and potential synergy between clinical
guideline representation models and business process representation languages, with
a view to automating clinical guidelines via mainstream business process automation
technology. This paper compares GLIF3 which is one of the significant clinical
guideline representation models with the representative power of UML with a case
study and show how such representational mapping can be achieved.
The paper begins with the description of Clinical Guideline Representation and
explains GLIF which is a one of the powerful guideline representation model using
the example of Diabetes Mellitus diagnosis. Clinical practice guidelines are the
recommended strategies for patient care. The benefit of these guidelines could be
obtained by using guideline-based computerized decision support at the point of
care. Clinical practice guidelines are time-consuming and expensive to develop. Once
the guidelines are developed, they should be shared among many institutions and/or
practitioners and this requirement means that a guideline representation model
should facilitate adaptation of guidelines to different setting and integration of
guidelines with local computer systems.
GLIF or GLIF3 stands for GuideLine Interchange Format is a guideline
representation model which facilitates guideline sharing and representing for a broad
variety of guideline types. GLIF supports process-oriented view of guidelines and
hence used for mapping business process representation. There are 5 main guideline
flowchart step types:

Action: This step specifies work to be performed. They are represented using
rectangles in the diagram.

Decision: This step is used for conditional flowchart traversal. There are two
types of decision steps:
a. Case steps: They represent the automatable decisions. They are
represented using diamonds in the diagram.
b. Choice steps: They represent choices that should be made by the
user. These steps are represented using hexagon in the diagram.

Branch: These steps are used to model concurrent guideline steps all of these
can occur in parallel. They are represented using triangles in the diagram.

Synchronization: They are used in conjunction with branch steps. When
multiple guideline steps follow a branch step, the flow eventually converges
into a synchronization step. Inverted triangle in the diagram represents a
synchronization step.

Patient-State: These steps characterize a patient’s clinical state. Ovals are
used to represent patient-state steps.
Figure 1: Diabetes Diagnosis guideline in GLIF
Figure 1 shows GLIF representation of Diabetes diagnosis. The subguideline in
figure 2 represents the actions that need to be taken when a patient has been
diagnosed with Diabetes Mellitus (DM).
Figure 2: Diabetes Mellitus action subguideline.
The paper then explains representing clinical guidelines in UML using the
same Diabetes Mellitus diagnosis case study. UML stands for unified modeling
language which is supported all major software modeling tool vendors and its
modeling elements are underpinned by a semi formal language which facilitates
rigorous
specification.
The
models
created
in
UML
generate
executable
specifications as well as facilitating sharing of designs. Figure 3 and 4 shows the
activity and sub activity diagram for representing diabetes mellitus diagnosis
guidelines.
Figure 3: UML Activity Diagram for diagnosis of diabetes mellitus
guideline
Figure 4: Diabetes Mellitus Sub Activity Diagram
An UML activity represents an action step in GLIF. The case step in GLIF is
represented using a decision point in UML. Series of activity followed by decision
point in UML represents a choice step in GLIF. A synchronization bar in UML maps
to branch and synchronization steps. Patient-state steps in GLIF can be mapped
to state elements or pre and post-conditions on activity in UML.
Advantages of UML

Encoding guidelines in UML allows customization which is needed to
apply the guideline within a particular hospital

The actual guideline models and specification can be delivered
between differing UML based modeling tools via UML’s XMI interface.

By using UML for clinical guideline representation, guideline developers
may avail of a wide choice of modeling tools, automated generation of
documentation, generation of executable code, traceability of the
development/local
customization
implementation automation.
and
in
certain
circumstance