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<article xmlns:xlink="http://www.w3.org/1999/xlink">
  <front>
    <journal-meta />
    <article-meta>
      <title-group>
        <article-title>Ontology-driven Data Management Design in Healthcare Domain: The ADCATER Experience</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Leonardo Cocco</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Paolo Fantozzi</string-name>
          <xref ref-type="aff" rid="aff1">1</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Domenico Lembo</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Umberto Nanni</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Federico Maria Scafoglieri</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>Department of Computer, Control and Management Engineering, University of Rome la Sapienza</institution>
          ,
          <addr-line>Rome 00185</addr-line>
          ,
          <country country="IT">Italy</country>
        </aff>
        <aff id="aff1">
          <label>1</label>
          <institution>Department of Law</institution>
          ,
          <addr-line>Economics, Politics, and Modern Languages</addr-line>
          ,
          <institution>LUMSA University</institution>
          ,
          <addr-line>Rome 00192</addr-line>
          ,
          <country country="IT">Italy</country>
        </aff>
      </contrib-group>
      <abstract>
        <p>In this paper, we outline our experience in implementing the data management component of a dataintensive healthcare application within the ADCATER project (Advanced Digital Solutions for Professional Food and Nutrition Catering Service), where an ad hoc ontology, tailored to the project's domain, plays a crucial role in driving the system design. We will discuss the creation process of this ontology, its underlying building principles, and how it aids the development of a reconciled database useful to integrate and consolidate heterogeneous sources of information, vital for the proper running of solution at hand. Here, the ontology is essential for harmonizing vocabularies and ensuring the establishment of a schema devoid of inconsistencies. Finally, we will explore how Business Intelligence services, operating on the foundation of the Data Warehouse built upon the reconciled database, are seamlessly aligned with the crafted ontology.</p>
      </abstract>
      <kwd-group>
        <kwd>eol&gt;Ontology</kwd>
        <kwd>Data Management Design</kwd>
        <kwd>Healthcare</kwd>
        <kwd>Business Intelligence</kwd>
      </kwd-group>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>1. Introduction</title>
      <p>The Advanced Digital Solutions for Professional Food and Nutrition Catering Service (ADCATER)1
is an international consortium focused on assisting healthcare professionals, especially
nutritionists, in measuring and managing hospitalized patients’ dietary intake via a digital meal
tracking solution. This healthcare application comprises two main components: a computer
vision-based system responsible for of identifying and categorizing patients’ food consumption
from images taken before and after meals, and a data management component that integrates
this information with data stored in various data sources. This new integrated data-layer,
suitably enhanced with Business Intelligence (BI) techniques, enables automatic reporting for
proactive patient care initiatives, forecasting and preventing possible outbreaks.</p>
      <p>In this paper, we will focus on the data management component, which is designed based on
an ontology specifically created for this purpose, called in the following ADCATER ontology.</p>
      <p>
        Ontologies formally conceptualize domains of interest, providing a common vocabulary of
classes, relationship between them and properties, emphasizing the sharing of knowledge and
the consensus about its representation [
        <xref ref-type="bibr" rid="ref1">1</xref>
        ]. Formalized through an interconnected semantic
network of information units, and sometimes called also Knowledge Graphs [2], they are the
backbone of Semantic Web [3], where the formalism for their specification has been concretely
standardized in the Ontology Web Language (OWL), finding a spread of applications in diferent
contexts. When ontologies are coupled with data [4, 5], they prove to be valuable allies for data
management [6]. They allow for semantic enrichment of the data to which they are connected,
enable forms of reasoning to enhance the information services and the quality of the data
itself [7]. This setting is usually known in literature as Ontology-based Data Management
(OBDM) [4, 8].
      </p>
      <p>While OBDM is preferable for expressing the potential of the ontologies in data-intensive
applications, especially those that also require data integration [9], in some contexts these
approaches and their implementations are not mature enough to be used or there are some
restrictions imposed by the working environment. This is precisely the case for the project
discussed in this paper. The project requirements within ADCATER impose specific constraints. For
example, the cloud technology stack defined for the solution in production must interface with
the existing applications of the industrial partner, FoodFix2, which are unable to accommodate
OBDM implementations. Additionally, the data architecture comprises BI technologies, which
poorly match OBDM. Furthermore, there is an inability to preserve the privacy of the stored
users’ data in the current OBDM systems, which is essential in healthcare settings.</p>
      <p>While having these project restraints, the role of the ADCATER ontology lies in driving the
design of the data management component, standardizing the structure and vocabulary of the
built solution. This feature is crucial in large projects and also allows the implementation to
be open to interfaces with other external systems in a more standardized and uniform way.
Moreover as mentioned before, the ADCATER ontology through a semiautomatic approximation
and translation is useful to generate a inconsistency-free reconciled schema integrating and
semantically harmonizing diferent data sources. Here, the reconciled database essentially bridges
the gap between OBDM and BI technologies, aligning them with ontology terminology and
basing their multidimensional objects (a.k.a. Cubes) on it. In order to openly share the material,
the ADCATER ontology can be downloaded from the following link https://tinyurl.com/4h95yvav.</p>
      <p>The paper is structured as follows. Section 1 is this introduction. In Section 2 we talk about
the source of knowledge to build the ADCATER ontology, the methodology and the tools used.
In Section 3 we introduce the ADCATER ontology and its modules. In Section 4 we discuss
the reconciled database and the BI services built starting from the ADCATER ontology. The
conclusion and the future works are delineated in Section 5.</p>
    </sec>
    <sec id="sec-2">
      <title>2. Knowledge sources, methodology and tools</title>
      <p>The ADCATER ontology, developed within a multidisciplinary project, formalizes and integrates
several domains, including biomedical/healthcare, with focus on patients’ status from a feeding
perspective, as well as nutrition and food related entities and processes.</p>
      <p>For the formalization of the ontology discussed in this paper, our primary sources of
knowledge to be conceptualized are derived from (i) medical questionnaires administered to patients,
2https://foodfixit.com/en/foodfix-the-right-solution-for-smart-food-management/
(ii) existing applications that handle medical data and (iii) insights gathered through interviews
with domain experts.</p>
      <p>(i) Medical Questionnaires. These questionnaires, mainly paper-based, serve two primary
purposes: those conducted upon admission provide valuable insights into the patient’s
medical history, while those administered during the hospitalization stay help in
monitoring the progression of the illness. These contain essential details for conceptual design
purposes, such as the information needed to calculate indicators to verify the patient’s
nutritional health. For example, among these, there are the patient’s weight, her/his
height and age, which translated into the Body Mass Index (BMI) parameter are useful
to compute a pleotra of standard scores for the assessment of malnutrition (GLIM [10],
SNAQ [11] etc.).
(ii) Existing Healthcare Applications. FoodFix is the industrial partner of the ADCATER
project whose main business is the catering management of hospitals. FoodFix’s systems,
and in particular their databases, although not in a terminologically standardized form
and not arranged for data-analysis purposes but mainly for operational ones, contain
useful information regarding food. Properly, they store fine-grain details concerning
patients’ meals, how they are made and the macro-nutrients composing them.
(iii) Interviews with Domain Experts. Undoubtedly, the primary source of knowledge
and guidance in refining an ontology lies with domain experts. This also holds for the
ADCATER ontology, which draws upon insights provided by nutritionists, physicians, and
experts in hospital settings. Each of them contributed to a specific part (module) of the
ADCATER ontology, either through interviews—question-and-answer sessions focusing on
diferent aspects of the ontology, or by expressing their requirements. Their contributions
were then traced back to verify the proper conceptualization.</p>
      <p>The creation of the ontology from a methodological point of view was accomplished through
an iterative refinement approach, which occurred through specialization of concepts and
relationships and by modularizing its parts. The vocabulary of the ADCATER ontology also follows
a logic of sharing, and thus all names used for artifacts were terminologically accepted by all
parties involved. To support all the creation steps and to facilitate the communication with non
data modeling experts, we were supported by a formal visual language for defining ontologies
called Graphol [12]. This language is the basis of a graphical tool called Eddy3. Such a tool
makes it possible to create ontologies using all the expressiveness of OWL through a visual
graph-like representation similar to UML and Entity-relationships diagrams. It allows to export
the ontology in text format following Semantic Web standards. Eddy is also useful for checking
possible inconsistencies at ontology building time. That is, through automatic reasoning
services related to the ontologies formal language, it is possible to check immediately whether
intensional inconsistency or cases of non-instantiable concepts or relations arise. To facilitate
the ontology definition process, we utilized collaborative text documents shared among all
project partners. These documents provide detailed descriptions of the technical choices made
for the formalization of each concept, relationship, and attribute within the ontology. This
approach enables us to track ofline changes and identify any potential discrepancies
3https://github.com/obdasystems/eddy</p>
    </sec>
    <sec id="sec-3">
      <title>3. ADCATER Ontology</title>
      <p>The ADCATER ontology is formalized using several ontology design patterns [13]. We exploit
the logical patterns N-Ary Relation and Tree appropriately suitably translated into the Graphol
language. Note that, the main purpose of the ontology is to guide the design of the
datarelated components of the ADCTARE solution, and thus it is not intended to cover all domain
aspects. Metrics detailing the size of the ADCATER Ontology, including the number of classes,
relationships and attributes, are given in Table 3.</p>
      <sec id="sec-3-1">
        <title>Concepts</title>
      </sec>
      <sec id="sec-3-2">
        <title>Relationships</title>
      </sec>
      <sec id="sec-3-3">
        <title>Attributes</title>
      </sec>
      <sec id="sec-3-4">
        <title>Axioms</title>
        <p>Number of
43
28
65
461</p>
        <sec id="sec-3-4-1">
          <title>3.1. Modules</title>
          <p>The ADCATER ontology is split into four modules, each of which is connected to at least one of
the others and named according to the aspects it covers. This division into modules facilitates
the creation and refinement of the ontology, Moreover, it has been of great help in the interviews
with the experts and to verify where the conceptualized knowledge comes from.</p>
          <p>Figure 1 shows a general overview of the ontology highlighting the modules and the main
concepts belonging to them.</p>
          <p>The four modules that define the ADCATER ontology are: Patient, Assessments, Measurements,
and Nutrition. The pivotal concept that unites the modules is that of Hospitalization.</p>
          <p>Figure 2 illustrates an excerpt of ADCATER ontology in Graphol, belonging to the Patient
module, focusing on the Hospitalization concept. Here rectangles define concepts, diamonds
denote relationships between them, and circles represent concept attributes. In the figure, the
concept Hospitalization, designed to represent the periods in which patient are admitted to
the hospital, has the attribute start_day tracking the start date of them. Patients, represented
by the class of the same name, have the attribute gender, identifying the patient’s gender
and is connected to Hospitalization with the relationship admitted_to. The ontology
excerpt also models finished hospitalizations, and the drugs (identified by API, i.e., the Active
Pharmaceutical Ingredient) administered to patients during their hospitalizations.</p>
          <p>In the following we briefly discuss every modules.</p>
          <p>Patient: This module deals with formalizing knowledge related to patients and the hospitals
in which they are hospitalized. The main concept on which the module revolves is that of the
patient (Patient). As discussed above, through the hospitalization concept, it is possible to
track information about the period in which patients have been in an hospital, the hospital
where they have been admitted, as well as their medical prescriptions.</p>
          <p>Assessments: Patient assessments corresponds to clinical analyses, whose detail and
outcomes are derived from medical questionnaires, and are used to compute scores for malnutrition
indicators. Each type of assessment is represented by a concept, whose attributes are useful
to calculate the indicators. The ontology also keeps track of the date of the calculation. This
thus makes it possible to historicize information, which is crucial for temporal analysis. In this
module, we also monitor the patient’s appetite, along with tracking information about their
sensory abilities, such as how they perceive taste and smells.</p>
          <p>Measurements: This module is designed to represent the physical and psychological status
of the patient. It contains key and historicized information on numerical indicators such as BMI,
height etc., as well as mobility and muscle mass. This module also takes care of keeping track
of the outcomes of medical teams, i.e. their diagnoses. This conceptualization, appropriately
incorporated with the other modules, allows for a more complete view of the inpatient stay.</p>
          <p>Nutrition: The nutrition module is concerned with food related information, for patient
food intake modeling and monitoring. Here, the patient’s nutritional profile is taken into account
and the nutritional plan assigned to the patient is mapped out. Data intended to instantiate this
module come from the computer vision component of the ADCATER solution, thus allowing
for the actual food consumption to be tracked. The amount of food consumed by a patient is
crucial information that the ontology models for comparison with prescribed food. The intake
of macronutrients can be easily obtained from the ingredients of the food items represented in
the ontology and the quantity of food consumed.</p>
        </sec>
        <sec id="sec-3-4-2">
          <title>3.2. Related Resources</title>
          <p>We conclude this section discussing related resources (ontologies, standard vocabularies etc.)
that have points in common with the ADCATER ontology.</p>
          <p>We will focus on resources pertaining to the areas of biomedical/healthcare field (which we
refer to simply as healthcare) and the food field as the ADCATER ontology does.
Healthcare ontologies. Ontologies, in the field of healthcare, describe the concepts of medical
terminologies and the relation between them, thus, enabling the sharing of medical knowledge.
Many medical ontologies are simply hierarchical vocabularies, in which the most general terms
appear at the hierarchy top-levels and the terms become more specific down the hierarchy. The
ontologies are typically quite big. The level of detail they reach is very high, and typically much
higher than the level needed in ADCATER. We below mention some of them:
• SNOMED [14]: it is a family of terminological systems, which is around by more than
40 years. In particular, SNOMED CT (clinical terms) [15], which merges together the
previous SNOMED RT [14] and Clinical Terms Version 3, is considered one of the most
comprehensive, multilingual clinical healthcare terminology in the world. SNOMED CT
provides several hierarchies of terms and includes Description Logics axioms. SNOMED
CT establishes a vocabulary for electronic health records, including symptoms, diagnoses,
medicines, etc.
• International Classification of Diseases (ICD) [ 16]: it is a nomenclature to classify diseases,
injuries, and causes of death. It is maintained by the World Health Organization (WHO)
and revised periodically. The current version is ICD-11 [17]. Some eforts have been
made in the literature to identify aspects that ICD-11 has in common with SNOMED.</p>
          <p>Nonetheless, they remain to date diferent vocabularies.
• The National Cancer Institute (NCI) Thesaurus [18]: it is a description logic-based
terminology, which is a part of the US National Cancer Institute Bioinformatics. It has been
created to be used by NCI’s researchers and the whole cancer community. It is designed
to serve several purposes such as annotation, search, and retrieval of data, automated
indexing, retrieving bibliography information, and linkage to heterogeneous resources.
• Medical Subject Headings (MeSH) [19]: it is a vocabulary specifically created for indexing
journal articles and books in the life sciences. It is managed by the United States National
Library of Medicine (NLM). It is also used to classify diseases studied by trials included in
the ClinicalTrials.org.</p>
          <p>Food ontologies. The definition of food thesauri, vocabularies and ontologies is more recent
with respect to the analogous efort done in the medical domain. Nonetheless, several resources
do exist that aim at promoting the standardization of terminology to be used to describe various
aspects of the Food domain, from the names of animals, plants, and fungi that can be used as
food for humans or domesticated animals, to prepared food and related products and processes.
Below we mention some initiatives and available controlled vocabularies:
• FoodWiki [20]: it is a Mobile Safe Food Consumption System based on the Food Ontology
Knowledge Base (FOKB), an OWL ontology that describes various kinds of food,
accompanied with nutritional values, and recommendation about daily assumption. FOKB is
structured in four subsections: person, disease, product, and food ingredients/compounds.
• AGROVOC [21]: it is a thesaurus providing terms in various languages to describe data
in the agriculture, fishing, forestry, and food domains.
• FoodOn [22]: it is a comprehensive food ontology belonging to the open source OBO
Foundry registry of ontologies for interoperable life science. It was originally based on
LanguaL, a food indexing system for the description of food source plant and animal
organisms, food preservation, cooking, packaging, etc. It has then been extended to also
cover food product related aspects and nutritional indicators.</p>
        </sec>
      </sec>
    </sec>
    <sec id="sec-4">
      <title>4. The Reconciled Database and Business Intelligence Services</title>
      <p>The core of the data management component, as highlighted in Figure 3 is the reconciled
database, which integrates diferent sources of information in order to serve BI services through
a data warehouse.</p>
      <p>Nutritional
Assessment
tool</p>
      <p>Alert</p>
      <p>INTEGRATED
RESPONSIVE SERVICES</p>
      <p>COMPONENT
Alert &amp; Nutritional
screening and
assasement tool</p>
      <p>CUBE layer</p>
      <p>KPI &amp;
dimensions
Reconciled DB
Data</p>
      <p>DataWarehouse
Summarized
(aggregated)</p>
      <p>Data
healthcare
expert
cube
modeler</p>
      <p>Ontology</p>
      <p>Metadata
Image
base
concept
modeler
operator</p>
      <p>ANALYTICAL
COMPONENT
Data Visualization
DATA MANAGEMENT</p>
      <p>layer
concept mapping and</p>
      <p>navigation
DATA SOURCES layer
business activities
anonymization</p>
      <p>Patient</p>
      <p>DB (EHR)
patient
health</p>
      <p>NutDriBtion cShuapinpDlyB
dietinafroy fnouotdrients supplolygicshtiacisn,</p>
      <p>Food DB
food
lifecycle
food
ingredients
computer vision
plate
images
physician
nutritionist
farmer</p>
      <p>caterer kitchen</p>
      <p>The reconciled database schema is created from the ontology via a semi-automatic process
based on approximation of the ontology language and transformation into digestible scripts by
relational technologies. This process was supported by the OBDM tool Mastro [23].</p>
      <p>Since this reconciled database is derived from the ADCATER ontology, it has several desirable
properties. For example, it is centered on subjects, rather than applications, and thus is
particularly suited for analytical purposes; it is rigorously documented; it is free from possible
inconsistencies or other modeling issues; table and field names are related to the ontology
terminology, so their semantics is clear and easily understandable by all stakeholders.</p>
      <p>Regarding the population of the reconciled database the data are taken from several data
sources such as the FoodFix application databases, those hospital repositories and nutritionists
databases and archives. These data are then mapped against the tables in the reconciled database
using standard techniques of data integration [24]. On top of the reconciled database, a BI
layer is built based on Data Warehouse (DW) technologies. In a DW, the main players are the
multidimensional objects, usually called cubes, which by aggregating data according to certain
dimensions allow for analyses that would otherwise be dificult to implement using classical
DBMs. These cubes, taking the terminology of the reconciled database are also aligned with that
of the ADCATER ontology. The design of the cubes therefore was directly done by inspecting it.</p>
    </sec>
    <sec id="sec-5">
      <title>5. Conclusion</title>
      <p>In this paper, we have introduced the ontology ADCATER, which formalizing the medical and
nutritional domain of the homonymous project, guides the implementation of the solution‘s data
management module. The ADCATER ontology by harmonizing terminology and providing an
inconsistency-free data layer enables the definition of a reconciled database to enable analysis
using business intelligence technologies. As future work, it would be interesting to expand
or integrate the knowledge with the help of other medical ontologies, such as those related
to mental health issues, and consequently accommodate BI techniques to get a better view of
patient status. From a data management and data quality perspective, it would be beneficial to
integrate data preparation techniques to address issues like entity disambiguation [25, 26] and to
extend data integration to include non-relational sources [27, 28], such as textual data [29, 30].</p>
    </sec>
    <sec id="sec-6">
      <title>Acknowledgments</title>
      <p>Scafoglieri’s research was entirely and exclusively supported by PNRR MUR project
PE0000013FAIR. Lembo’s research was supported by EU ICT-48 2020 project TAILOR (No. 952215), EU
ERA-NET Cofund ICT-AGRI-FOOD project ADCATER (No. 40705), and PNRR MUR project
PE0000013-FAIR. Nanni’s research was supported by EU ERA-NET Cofund ICT-AGRI-FOOD
project ADCATER (No. 40705).
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