Poster presented at the 2nd ACM International Health Informatics Symposium SIGHIT in 2012 See: http://www.mlhim.org http://gplus.to/MLHIM and http://gplus.to/MLHIMComm for more information about semantic interoperability in healthcare. #mlhim #semantic_interoperability #health_informatics

1. Implementing a Specification for Exceptional Data
in Multilevel Modeling of Healthcare Applications
Timothy Wayne Cook, Luciana Tricai Cavalini
Multilevel Healthcare Information Modeling (MLHIM) Laboratory
National Institute of Science and Technology – Medicine Assisted by Scientific Computing
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Abstract. Missing information is a key issue for the achievement of interoperability and semantic coherence in healthcare information systems. This
paper presents the implementation of the Exceptional Package in the Multilevel Healthcare Information Modeling (MLHIM) specifications, and it
describes two use cases where missing information is critical for decision-making and healthcare technology assessment.
Introduction and Method. The issues related to missing information bring several analytical problems to biomedical research and there is no
consensus on how to handle it Since everything about individuals can, at any point in time, affect their health, this is a central issue for the research field
of information applied to life sciences [6].
Some situations where this can be applied include: incomplete information due to interviewing patients with cognitive impairment, refusal to answer,
illegible handwriting, inaudible records of interviews, failure in vital signs processing, among many others.
The ISO 21090 standard is an attempt to solve the problem of recording missing data for electronic health records [3]. This standard is based on the
Health Level 7 (HL7) data types, which might have the “NullFlavor” property. This “NullFlavor” property, however, has raised some questions from the
implementers of HL7-based healthcare applications such as lack of support for optionality and reasoning (e.g., a Boolean data type with 3-valued
logic) [5]. Mohan [5] uses the word “exceptional” to define “values other than recommended or allowed” on HL7 Version 3; in other words, the
NullFlavors.
Since adjectives are noun modifiers and the exception itself is not empty, this makes the word “exceptional” a better choice, in terms of defining what
is called “null” or “void” flavor in HL7. On the subject of “flavor” (or “flavour”), there is the additional inconsistency caused by the two different spellings.
This paper presents the solution for handling missing information implemented in the Multilevel Healthcare Information Modeling (MLHIM) specifications.
Results. The Multilevel Healthcare Information Modeling (MLHIM) specifications are a set of fully open specifications based on the openEHR dual
model [1] and improved by the adoption of XML technologies for the definition of constraints on the Reference Model.
The MLHIM Information Model is defined by Concept Constraint Definitions (CCDs), expressed in XSD files. A CCD is an expression of domain
(healthcare) content in the form of structured instruction of combinations and restrictions to the MLHIM Reference Model classes [2].
In the MLHIM specifications version 2.3.0 (https://launchpad.net/mlhim), the Common package contains an abstract class called ExceptionalValue
and its children (Fig. 1) which provide semantics for data that are exceptional in some way. This is an approach to abstracting the concept of “Null
Flavours” so that they may more readily be transferable between systems as a hierarchy of types. The result is that the concept of exceptional data
semantics may be extended in any implementation and still be valid without the requirement of a formal, shared terminology. This is, until now, an
unresolved issue in health information systems. In the MLHIM specifications, all DvAny children data types carry the “ev” attribute so that in any case
where the actual value of the data is Null, the “ev” attribute contains the semantics. The attributes “name” and “meaning” are redefined in each class
of the hierarchy. This provides the effect of using constants for each type.
In addition, this package defines the exceptional values from the NullFlavor Enumeration table in ISO/DIS 21090, “7.1.4 Null and NullFlavor”. However,
any implementation that has a requirement for additional entries may add them to their implementation as descendants (specializations) of any of
these classes and they are still valid values. Thus, the implementation of the ExceptionalValue class and its children on the Common package of the
MLHIM specifications version 2.3.0 enables semantic coherence between systems based on those specifications, not only for valid data, but also for
missing data.
As an example we will use this, very possible, scenario. Annie is an elderly lady with a small dog as a pet. She is being visited by a social worker to
check up on her one Spring morning. The social worker uses a standardized questionnaire to assess Annie's mental functionality. Since Annie has
difficulty seeing and writing the social worker asks Annie the questions in concert with some general conversation. For auditing purposes and since the
social worker cannot fully record everything Annie says (including inflection), the session audio is recorded.
Later that day Annie takes her dog for their usual walk and is struck
by an automobile driven by Joe. Joe has had a spotless driving record
for more than 20 years. Annie is attended by first responders at the scene.
Transported to a nearby hospital, Annie is treated and admitted for observation.
Of course the trauma is upsetting and she has trouble
answering all of the questions from the healthcare professionals.
Her primary care physician is consulted upon Annie's admission and he relates
the fact that Annie was supposed to have been visited the day of the accident by a
social worker. A transcript of the visit and a copy of the audio is obtained to try
to determine if Annie was exhibiting any cognitive issues before the accident.
A quick scan of the transcript reveal there are several places that simply say “inaudible”.
So this leaves the healthcare professionals with more questions. Did Annie mutter
unintelligibly? Did answer intelligibly but to softly to be recorded?
Did the dog bark? Was there excessive noise outside? Three months later we
have insurance companies and Annie's attorneys involved in deciding who is at fault
and to what degree. Therefore the answers to these questions are relevant outside
of the healthcare domain as well.
For one more short example let us consider a medical monitoring device used
in a critical care setting. It can record information that is outside of normal bounds
as well as the cause for many types of missing data. Within its own
information domain the exceptional data has meaning. Is data missing due to
equipment ‘blips’ or because the data wasn’t sensed from the patient? How can this
data be transferred to an EMR with semantics? What is the universe of these
various exceptional data items? They certainly having meaning if not within the
individual patient records; they are valuable for health technology assessment, Figure 1. The ExceptionalValue class and its child classes of
population health reviews, etc.
The goal of the MLHIM Exceptional Package approach is to make those exceptional the Common package in MLHIM 2.3.0.
items available with semantics, thus overcoming the current issues related to missing
data in biomedical sciences.
[1] Beale, T. and Heard, S. 2008. openEHR Architecture Overview. openEHR Foundation, London, UK.
[2] Cavalini, L. T., Cook, T.W. Health informatics: the relevance of open source and multilevel modeling. IFIP Advances in Information and
Communication Technology 365 (Oct. 2011), 338-347.
[2] ISO TC 215. 2008. ISO/DIS 21090:2008 - Health informatics - harmonized data types for information interchange. International Organization for
Standardization, Geneva,Switzerland.
[3] Mohan, A. 2008. Null flavors in HL7V3. http://healthcareinformatics3000feet.blogspot.com/2008/10/null-flavors-in-hl7v3.html.
[4] Smith, B. 2008. Flavors of null. http://hl7-watch.blogspot.com/2008/10/flavors-of-null.html.
[5] Smith, P. C., Araya-Guerra, R. Bublitz, C., Parnes, B., Dickinson, L. M., van Vorst, R., Westfall, J. M. and Pace, W.D. 2005. Missing clinical information
during primary care visits. JAMA 305, 24 (Jun. 2011), 2493-2592. DOI= http://dx.doi.org/10.1001/jama.293.5.565.
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