An ontology for healthcare systems Francois Goyer 1,2, Paul Fabry 1,2, Adrien Barton3,1,2 and Jean-François Ethier 1,2 1 Centre Interdisciplinaire de Recherche en Informatique de la Santé de l’Université de Sherbrooke (CIRIUS), Université de Sherbrooke, Québec, Canada 2 Groupe de Recherche Interdisciplinaire en Informatique de la Santé (GRIIS), Université de Sherbrooke, Québec, Canada 3 Institut de Recherche en Informatique de Toulouse (IRIT), CNRS, Université de Toulouse, France Abstract Modern patient care is becoming increasingly complex and is now most commonly delivered through healthcare systems. Understanding the structure surrounding care is an important tool in optimizing it. This article proposes a unified ontological analysis of healthcare systems following the OBO Foundry Methodology, by exploring the relationships between the caring of individuals, the health workers and healthcare providing organisations. This ontological model strives to enable interoperability in the context of Learning Health Systems. Keywords 1 healthcare, healthcare procedure, roles, healthcare ontology 1. Introduction While information concerning health procedures themselves is important, the context in which they are performed is also valuable for an Learning health systems (LHS) aim at LHS. For example, considerations on the location improving patient care by documenting clinical (ambulatory vs hospital) [4] or profession of the data, deriving knowledge from it, and modifying health professionals involved in a health its practices considering this emerging procedure [5,6] may also influence the quality, knowledge. Advances in modern healthcare have completeness or cost-effectiveness of patient care. significantly increased the variety and quantity of Such information can lead to the optimization of available clinical data. However, the fact that this (often) limited healthcare resources. This is for data is scattered among different record sources example particularly important to evaluate the with possibly different semantics is a major hurdle impacts of the increase in telemedicine activities to the implementation of LHS. To address this, the seen in the recent months due to covid-related use of applied ontologies is a promising solution restrictions [7]. Such questions are at the core of as they provide source-independent large initiatives like the Health Data Research representation of clinical data. Network Canada [8] aiming at facilitating the use In prior work [1], we described the different of medico-administrative data across multiple processes directly involved in the health care of provinces and territories to explore both clinical individuals, namely, health procedures and health and management questions. Another domain is activities. These classes laid the groundwork to the use of quantified-self measurement devices, represent health data, whether it emanates from which is expanding. It offers new clinical home (e.g. a report of a blood pressure opportunities but also additional challenges in measurement with one’s personal machine) or handling and analyzing data correctly [9] from organisations such as laboratory evaluations This mandates the need for an ontological [2] or prescriptions [3]. analysis of the structure of healthcare systems and ICBO 2022, September 25–28, 2022, Ann Arbor, MI, USA EMAIL: francois.goyer@usherbrooke.ca (A. 1); paul.fabry@usherbrooke.ca (A. 2); adrien.barton@irit.fr (A. 3); jf.ethier@usherbrooke.ca (A. 4) ORCID: 0000-0002-7626-1026 (A. 1); 0000-0002-3336-2476 (A. 2); 0000-0001-5500-6539 (A. 3); 0000-0001-9408-0109 (A. 4) 2022 Copyright for this paper by its authors. Use permitted under Creative Commons License Attribution 4.0 International (CC BY 4.0). CEUR Workshop Proceedings (CEUR-WS.org) ©️ CEUR ceur-ws.org Workshop ISSN 1613-0073 Proceedings how they relate to health procedures; the latter While certainly not systematic nor approved being focused on the “what” of clinical data, by an authoritative body, some stakeholders [6] whereas the former in the “where”, “when”, argue both spellings “healthcare” and “health “by/to whom” and “why”. care” may be used independently to delineate This task is made challenging by the fact that these different facets of caring for someone’s healthcare systems are diverse and common health. In this scheme, the term “health care” language terms used to described them are often would refer to the acts of providing care while the ambiguous. In accordance with the principles of term “healthcare” refers to the industry itself. the OBO Foundry [56], we propose an ontology Considering the lack of consensus, we have for healthcare system centered on a representation chosen for the class labels introduced in this work of its organisations. In the following we begin to use the term “healthcare” exclusively in the with a review of existing definitions surrounding context of organisations. To avoid confusion, healthcare and their shortcomings. We then when referencing the processes directly involved outline our proposed model with examples in health, the “care” part of “health care” will be delineating their implications. dropped in favor of “health”. Other classes pertaining to the healthcare 2. State of the art system present in OBO also share considerable overlap. The term “hospital” provides a notable example: The terms “healthcare” or “health care” are • NCIT: hospital - An institution that commonly used to describe different entities, provides medical, surgical, or psychiatric care and often interchangeably. Online dictionaries treatment for the sick or the injured. provide very broad definitions: • ENVO [16]: hospital - A hospital is a • Merriam-Webster [12]: health care or building in which health care services are healthcare - efforts made to maintain or restore provided by specialized staff and equipment. physical, mental, or emotional well-being These distinct entities are both conveyed by especially by trained and licensed professionals the indefinite term “hospital”, the facility or the • Cambridge dictionary [13]: healthcare healthcare organisation. A detailed analysis of all or health care - the activity or business of healthcare related terms in the OBO foundry is providing medical services outside the scope of this work, however we In both cases, the exact scope of what believe these excerpts are sufficient justification constitutes “healthcare” is left vague. For for a uniform and dedicated ontology of Merriam-Webster, “healthcare” seems to involve healthcare systems. trained and licensed professionals but not exclusively while Cambridge definition encompasses both processes (activity) and 3. Methodology organisations (business). This duality is also present in classes present During the development of an ontology, it is in the OBO foundry: important to respect the univocity of terms, that is • GSSO [14]: health care (BFO:process) - that the terms employed are always used with the The prevention, treatment, and management of same meaning [17]. Therefore, we avoid the illness or the preservation of mental and physical single use of polysemous terms such as well-being through the services offered by the “healthcare” as a class label. Instead, using medical, nursing, and allied health professions specific examples, the main entities related to • OPMI [15]: health care (BFO:process) - healthcare will be outlined. Subsequently, several Health care or healthcare is the maintenance or classes and object properties are proposed improvement of health via the prevention, allowing us to formalize these entities based on a diagnosis, and treatment of disease, illness, injury, methodology consistent with OBO foundry and other physical and mental impairments in principles. human beings. These classes are constructed using a realist The definition by GSSO incorporates the approach based on BFO [11]. Textual definitions notion that healthcare is delivered through following an Aristotelian structure and important structured services (organisation) while the OPMI axioms are provided. In addition, in accordance one refers to the processes themselves irrespective with the OBO Foundry principle of respect of of context. orthogonality between ontologies, we will reuse injury. It has some components that are planned as much as possible classes and object properties processes, including at least one that is a health from other ontologies. Additionally, object activity.” properties are introduced to describe the roles the Consider the following example: Mr. Jones various actors play in processes. They allow a feels unwell and decides to measure his pulse more precise characterization of the participants using his smartwatch. In this case, the evaluation of health procedures. of his pulse is a health procedure (hp1). Noticing that his pulse is abnormally high, he decides to go 4. Results to the nearest hospital’s emergency (hf1). The triage nurse (Nurse Betty) also performs a pulse 4.1. Taxonomy and class structure evaluation using her machine (health procedure hp2); however, this pulse evaluation is a part of The taxonomy of the different classes another process, a healthcare service delivery discussed below are presented in figure 1 and their (he1). relations in figure 2. Healthcare service delivery =def “A health procedure under the responsibility of an organisation that aims at providing a desired effect on the health status of individuals and their communities. It is usually composed of health procedures and possibly associated ancillary processes. It stems from an agreement between a requesting agent and a healthcare organisation” This pulse measurement hp2 is a part of an emergency department visit (which is a healthcare service delivery), a service agreed upon by a healthcare organization (ho1) and an organism (Mr. Jones) which was initiated when Mr. Jones requested the services of the healthcare organisation for his condition. It might include associated healthcare ancillary processes such as the provision of accommodation or meals. An ontology of services is beyond the scope of this article, but we can note some important aspects here. According to Nardi et al. [18], a service encompasses processes and distinct entities such Figure 1 - Taxonomy of the different classes as commitments or compensation. In the present related to healthcare article we focus on the service processes, which we refer to as “service deliveries”. Mr. Jones was 4.2. The different aspects of the requesting agent for this service, however in some instances the requesting agent might differ healthcare from the individual for which care is intended for (pediatrics, veterinary medicine etc.). As outlined above, we consider the scope of Furthermore, these healthcare service “healthcare” too vast for a single entity (existing deliveries realize a healthcare organisation role: usages would point towards it being both a healthcare service delivery subClassOf continuant and an occurrent for example). Instead, (realizes some healthcare organisation role) we propose a clear distinction between the With: different entities involved. Central to this healthcare organisation role =def “A role that framework, is the previously defined health inheres in an organisation and is realized by procedure [1]. providing some healthcare service delivery.” health procedure =def “A planned process And: guided by the objective of contributing to a healthcare organisation =def “An organisation desired effect on the health status of an organism that bears a healthcare organisation role” or several organisms achieved through the treatment, diagnosis, or prevention of disease or Figure 2 - Schematic representation of the main classes surrounding healthcare procedures Healthcare services delivery are planned independently of any organisation. We therefore processes and are therefore directed by plan define: specifications. One such plan specification is: healthcare worker =def “A health worker who healthcare service patient specification =def “A is a member of a healthcare organisation” directive information entity identifying an healthcare worker subClassOf (health worker organism for whom a plan of healthcare service AND (member_of some healthcare delivery aims at providing a desired effect to its organisation)) health status.” (that is, a healthcare service patient specification can only direct a healthcare service 4.4. Participants in health delivery involving the specified patient) procedures 4.3. Health worker and healthcare With regards to clinical data, being able to workers describe the exact nature of the participation of agents in health procedures is paramount. In Similarly to the way we have separated health Mr. Jones’ pulse measurement, both he and the procedures from healthcare service deliveries, we triage nurse participate in this health procedure, define the class health worker independently of albeit in significantly different ways. To better any organisational context. delineate these differences, we begin by health worker =def “An organism that is the considering that health procedures can themselves bearer of a health worker role.” be composed of different processes. In turn, these health worker role =def “A role that inheres in processes can realize specific roles. Following an organism as a consequence of a training of this this schema, we define two roles: health organism to perform some health procedures” procedure performer role and health procedure Health worker roles inheres in organisms2 recipient role. The performer role is realized by because they have been trained in a specific field. processes an agent plays in a health procedure, the Examples include physician roles and recipient role by the processes that are done by an physiotherapist roles. Health workers commonly organism for which the desired outcome is aimed provide health procedures as members of a for; therefore, health procedure recipient role is a healthcare organization, although they might also subclass of health procedure performer role. more rarely provide such procedures 2 We chose a conservative stance with the use of organism to possibly include service animals. This can be represented by two ternary 4.5. Healthcare service delivery and relationships3: participates_as_health_procedure_performer health procedures _in_process(X,Y,Z): The process Z has as proper part a process Y that realizes a health procedure Healthcare organisations provide different performer role that inheres in organism X. types of services which can be distinguished participates_as_health_procedure_recipient_ depending on whether they aim at the health of a process(X,Y,Z): The process Z has as proper part single individual or a population. a process Y that realizes a health procedure The class populational healthcare service recipient role that inheres in organism X. delivery aims at the health of a group of organisms To alleviate the model, we introduce two but selects this group by specifying a common object properties derived from participate_in that trait among them, thus characterizing a derive a binary relation from each of these ternary population. On such example would be a smoking relations: cessation outreach campaign in a city. The group X participates as health procedure performer includes smokers living in a given city and might in Z =def there is some Y such that change in time (as people move in and out of the participates_as_health_procedure_performer_in city or start or stop smoking, hence the individuals _process(X,Y,Z) forming this population change in time). X participates as health procedure recipient in On the other hand, individual healthcare Z =def there is some Y such that service deliveries are intended for specific participates_as_health_procedure_recipient organisms and are directed by directive _in_process(X,Y,Z) information entities: Natural language definitions would be as individual healthcare service delivery =def “A follows: healthcare service delivery that targets some X participates as health procedure performer specified individuals.” in Z: The agent X participates in the health individual healthcare service delivery procedure Z as a performer. subClassOf (directed_by some healthcare service X participates as health procedure recipient in organism specification) Z: The agent X participates in the health procedure Similarly to health procedures, not all Z and Z aims at improving X’s health status. individual healthcare service deliveries have the Following our example, Mr. Jones participates targeted organism as participant. Those that do are as health procedure recipient and the triage nurse divided into healthcare encounters: participates as health procedure performer in the healthcare encounter =def “A temporally- measurement of Mr. Jones’ pulse hp2. When connected individual healthcare service delivery Mr. Jones measured his own pulse (hp1), he was that aims to improve, maintain or restore the a bearer of a health procedure recipient role and health of some participating organism” also a bearer of a health procedure performer role. Healthcare encounters are services which Not all health procedures have a recipient role: concern a particular organism as a target and for sometimes the target (organism for which a which that organism is a participant as a recipient. desired effect is intended) of these processes does The recipient of these encounters can be defined not participate in them. For example, medical in the following way. history taking (health procedures) are routinely X participates as health encounter recipient in done without the participation of the target, Z: The organism X participates in the health notably in pediatrics or geriatric care. Likewise, a encounter Z and Z aims at improving X’s health radiologist’s interpretation of an MRI does not status. involve the participation of the subject, whereas healthcare encounter subClassOf the process of image acquisition involved him as (has_participant_as_health_encounter_recipient a recipient. some OBI:organism) Mr. Jones’ visit to the emergency department is a healthcare encounter in which Mr. Jones is the recipient. Healthcare encounters can also be structured by their location: 3 In the two definitions below, Y can be seen as a processual roles in the sense defined by Frank Loebe [19], where X is the participant of Y. Such roles can be related to process profiles [20]. facility-based healthcare encounter =def “A some OBI:organism AND healthcare encounter during which the recipient is (located_in_at_some_time some healthcare expected to be located in a healthcare facility and facility) is indeed located in one at least for part of its facility-based healthcare encounter participation as a recipient” subClassOf (has_part_that_occurs_in healthcare facility-based healthcare encounter facility) subClassOf (has_healthcare_encounter_recipient Figure 3 - Instances used in the two examples from section 4.2. The top part for Mr. Jones’s pulse measurement at home, the bottom for his visit to the emergency department. Dashed lines represent relations between the mentioned instances that do not generalize in axioms at the class level. remote healthcare encounter =def “A participates_as_health_procedure_anesthesiologi healthcare encounter where the organism that st could be used to describe a surgical health participates as performer does so only remotely, procedure. Of note, terms like “surgeon” and via telecommunication.” “anesthesiologist” are often used to refer to social There is considerable overlap in common roles or former training of an individual. In the terms used to describe healthcare facilities. Terms example above, these roles are concretized by like “hospital”, “clinic” or “medical center” are specific parts of a health procedure. For example, often used interchangeably and can hold different in an emergency, an anesthesiologist might meanings depending on jurisdictions. participate as a surgical assistant for a given Furthermore, these words do not explicitly procedure. delineate their dual nature as in practice the terms The use of (binary) object properties derived can be used indiscriminately to identify either the from the ternary relationships involved in these organisation or the building. It is also common for roles can be seen as a practical way to relate a single healthcare organisation to operate in agents and how they participate in processes several facilities and the type of healthcare without the need to formally define the different services provided may differ from one facility to parts of health procedures. another. Therefore, instead of using these terms as There is a large overlap between classes class labels and fixing their meaning arbitrarily, presented here and classes found in OMRSE and we propose avoiding them in favor of terms whose OGMS [22]. One such overlap is the class meanings are better circumscribed such as the OMRSE:health care encounter: classes from OMRSE [21]: hospital facility and OMRSE:health care encounter =def “A hospital organisation. temporally-connected health care process that has Lastly, we define healthcare procedure: as participants an organisation or person realizing healthcare procedure =def A health procedure the health care provider role and a person realizing that is part of a healthcare service delivery and the patient role. The health care provider role and that is performed by a healthcare worker while patient role are realized during the health care realizing its health care worker role. encounter.” healthcare procedure subClassOf This class and our proposed healthcare (has_participant_as_health_procedure_recipient encounter class differ mainly in their scope. In the some OBI:organism) latter, they include only processes of healthcare individual healthcare service delivery organisation, for example hospitalizations or out- subClassOf (has_part some healthcare patient visits. In turn, health procedures such as a procedure) nurse evaluation are part of these encounters. For The different axioms presented here enable the the former, both processes are included. It also explicit representation of all the different entities refers to the term “patient” which would deserve involved in Mr. Jones’ pulse measurement in the in itself further scrutiny as it is also used in emergency department: the healthcare different contexts to refer to various aspects, organisation, the recipient, the performer and the including administrative (registration), relational healthcare facility (Figure 3). (patient of) and participant in a care process. The proposed classes in this paper remain 5. Discussion largely aligned with existing classes but bring more discerning power to allow the correct representation of processes, agents and associated In this work we detailed the different entities data in the health domain. Further work and at play in organisational healthcare and how they discussions with OMRSE and OGMS teams are relate to health procedures, with a special needed in order to identify how to best integrate emphasis on the axiomatization of the different these classes in the current ontological landscape. participants in the relevant processes. Through dedicated object properties, recipients and performers can be related to health procedures. In 6. Acknowledgements addition, by adding sub-properties to participates_as_health_procedure_performer, it is We would like to thank our many colleagues possible to associate specific parts of a health from the Groupe de Recherche Interdisciplinaire procedure to an agent. For example, en Informatique de la Santé (GRIIS) for their participates_as_health_procedure_surgeon and support and insightful discussions. Pr. Ethier is a grant recipient from FRQS. 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