=Paper= {{Paper |id=Vol-3740/paper-02 |storemode=property |title=Overview of MultiCardioNER task at BioASQ 2024 on Medical Specialty and Language Adaptation of Clinical NER Systems for Spanish, English and Italian |pdfUrl=https://ceur-ws.org/Vol-3740/paper-02.pdf |volume=Vol-3740 |authors=Salvador Lima-López,Eulalia Farre-Maduell,Jan Rodríguez-Miret,Miguel Rodríguez-Ortega,Livia Lilli,Jacopo Lenkowicz,Giovanna Ceroni,Jonathan Kossof,Anoop Shah,Anastasios Nentidis,Anastasia Krithara,Georgios Katsimpras,Georgios Paliouras,Martin Krallinger |dblpUrl=https://dblp.org/rec/conf/clef/Lima-LopezFRRLL24 }} ==Overview of MultiCardioNER task at BioASQ 2024 on Medical Specialty and Language Adaptation of Clinical NER Systems for Spanish, English and Italian== https://ceur-ws.org/Vol-3740/paper-02.pdf
                         Overview of MultiCardioNER Task at BioASQ 2024 on
                         Medical Specialty and Language Adaptation of Clinical
                         NER Systems for Spanish, English and Italian
                         Salvador Lima-López1,* , Eulàlia Farré-Maduell1 , Jan Rodríguez-Miret1 ,
                         Miguel Rodríguez-Ortega1 , Livia Lilli2,3 , Jacopo Lenkowicz2 , Giovanna Ceroni4,5 ,
                         Jonathan Kossoff5 , Anoop Shah4,5 , Anastasios Nentidis6,7 , Anastasia Krithara5 ,
                         Georgios Katsimpras5 , Georgios Paliouras5 and Martin Krallinger1
                         1
                           Barcelona Supercomputing Center, Plaça Eusebi Güell, 1-3, 08034 Barcelona, Spain
                         2
                           Real World Data Facility, Gemelli Generator, Fondazione Policlinico Universitario Agostino Gemelli IRCCS, Rome, 00168, Italy
                         3
                           Catholic University of the Sacred Heart, Rome, 00168, Italy
                         4
                           University College London, UK
                         5
                           University College London Hospitals NHS Foundation Trust, UK
                         6
                           National Center for Scientific Research “Demokritos”, Athens, Greece
                         7
                           Aristotle University of Thessaloniki, Thessaloniki, Greece


                                      Abstract
                                      Transformers and large language models (LLMs) are increasingly used for clinical data analysis, mostly in English,
                                      but also in many other languages used within medical care systems. To comply with clinical standards, it is
                                      critical to evaluate the generated results by means of benchmarking efforts based on high-quality manually
                                      annotated corpora. To foster the adaptation of general clinical natural language processing (NLP) components
                                      to the characteristics of medical specialties, as well as exploring cross-language adaptation techniques, we
                                      propose the MultiCardioNER task at BioASQ 2024. MultiCardioNER focuses on the adaptation of named entity
                                      recognition (NER) systems trained on multispecialty clinical case reports to cardiology, since cardiovascular
                                      diseases are the leading cause of death globally. The MultiCardioNER task covered two entity types (diseases and
                                      medications) in case reports written in three languages (Spanish, English and Italian). To generate a comparable
                                      Gold Standard clinical NER corpus, we used neural translation, annotation projection and manual annotation
                                      correction by domain experts. Top scoring teams reached very competitive results for disease (F1-score 0.8199)
                                      and medication mentions (0.9277) in Spanish and also obtained very competitive scores for English (F1-score
                                      0.9223) and Italian (F1-score 0.8842). These results suggest that adaptation of general clinical NLP components to
                                      a specific clinical specialty can improve the overall results and that cross-language adaptation of clinical NLP
                                      components using neural translation and expert-in-the-loop annotation might speed up the implementation of
                                      clinical entity extraction systems. The MultiCardioNER corpora, as well as a silver standard made up of predictions
                                      of participating systems over the background set, are available at: https://zenodo.org/records/11368861.

                                      Keywords
                                      named entity recognition, cardiology, subdomain adaptation, multilingual, clinical NLP




                         1. Introduction
                         Cardiovascular diseases (CVDs) represent a leading cause of death and morbidity worldwide and,
                         therefore, are responsible for considerable disability costs every year. Cardiology is a medical field with

                          CLEF 2024: Conference and Labs of the Evaluation Forum, September 09–12, 2024, Grenoble, France
                         *
                           Corresponding author.
                          $ salvador.limalopez@bsc.es (S. Lima-López); eulalia.farre@bsc.es (E. Farré-Maduell); jan.rodriguez@bsc.es
                          (J. Rodríguez-Miret); livia.lilli@policlinicogemelli.it (L. Lilli); jacopo.lenkowicz@policlinicogemelli.it (J. Lenkowicz);
                          g.ceroni@ucl.ac.uk (G. Ceroni); j.kossoff@nhs.net (J. Kossoff); a.shah@ucl.ac.uk (A. Shah); tasosnent@iit.demokritos.gr
                          (A. Nentidis); akrithara@iit.demokritos.gr (A. Krithara); gkatsibras@iit.demokritos.gr (G. Katsimpras);
                          paliourg@iit.demokritos.gr (G. Paliouras); mkrallin@bsc.es (M. Krallinger)
                           0000-0002-7384-1877 (S. Lima-López); 0009-0000-0793-981X (J. Rodríguez-Miret); 0009-0000-0188-079X
                          (M. Rodríguez-Ortega); 0009-0005-3319-7211 (L. Lilli); 0000-0002-8366-1474 (J. Lenkowicz); 0000-0002-8907-5724 (A. Shah);
                          0000-0002-3782-4412 (A. Nentidis); 0000-0003-0491-4507 (A. Krithara); 0000-0003-3697-941X (G. Katsimpras);
                          0000-0001-9629-2367 (G. Paliouras); 0000-0002-2646-8782 (M. Krallinger)
                                   © 2024 Copyright for this paper by its authors. Use permitted under Creative Commons License Attribution 4.0 International (CC BY 4.0).


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Workshop      ISSN 1613-0073
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its own concepts and expressions of great relevance, as cardiovascular diseases are highly prevalent
worldwide. Analysis of unstructured medical data, such as clinical notes or medical publications, may
provide an opportunity to improve the characterization of cardiac pathologies. The extraction of clinical
variables from medical content is key to enabling healthcare data analytics, improving patient care
and advancing precision medicine. Information contained only as free text within Electronic Medical
Records is currently mostly unused due to the difficulty of extracting relevant data from very diversely
written data sources. Additionally, the distinctive language of each medical specialty calls for more
specialized automatic semantic annotation resources in English and any language used in clinical
services.
   Due to its importance and the need to improve the extraction, use, and ultimately exploitation of
patient data suffering from cardiovascular conditions, efforts have been made to implement natural
language processing (NLP) solutions to classify or extract key variables from cardiology clinical content.
Using results generated by NLP technologies might contribute to improving outcomes and understanding
disease in cardiology. In order to account for the diversity and heterogeneity of NLP research applied to
cardiology, several review articles have tried to systematically characterize the various NLP application
scenarios adapted to handle cardiovascular disease medical documents [1]. These included applications
related to heart failure [2], coronary artery disease, general cardiology or valvular heart disease [3, 4].
Efforts were also made to extract, by means of NLP tools, symptoms [5, 6], vital signs [7], heart function
measurements [8], risk factors [4], or cardiovascular comorbidities [9] as well as social risk factors [10]
or diagnostic codes of common cardiovascular diseases [11]. Some other attempts were also made to
explore the use of NLP approaches to extract Framingham criteria [12] or New York Heart Association
classifications from unstructured clinical notes [13, 14, 15].
   General clinical domain pre-training does not necessarily transfer well to all medical sub-specialties
or disciplines because of the use of highly specialized medical language, as encountered in cardiology
clinical case reports or cardiology clinical notes. Domain adaptation strategies may have a great potential
to improve NLP solutions for practical settings, real-world scenarios and industrial applications [16].
Also, adaptation of clinical NLP solutions across languages other than English is necessary and requires
collaboration between researchers to accelerate progress in non-English clinical NLP [17].
   In the case of Spanish, general clinical NLP datasets and resources, such as the DisTEMIST,
SympTEMIST, PharmaCoNER, and MedProcNER corpora and systems, have been released. How-
ever, (a) the interplay and complementarity of multi-label entity extraction approaches were neither
targeted nor evaluated, and (b) how such approaches could be adapted to handle multiple languages
was not tested.
   To address these issues and promote the development of comparable clinical NLP components adapted
to a specific clinical domain across several languages, we have organized the MultiCardioNER shared
task. This paper presents an overview of the data, methodologies and results of MultiCardioNER. It
is structured as follows: Section 2 introduces the shared task, including its sub-tasks and evaluation
methods. Next, Section 3 describes the different corpora used as part of MultiCardioNER, namely
DisTEMIST, DrugTEMIST and CardioCCC, as well as other associated resources, while Section 4
presents the participation results and proposed methodologies. Finally, Section 5 concludes the paper
with a discussion of some of the most interesting aspects, learned lessons, future work and more.


2. Task description
2.1. Shared task description
The MultiCardioNER task participants were asked to implement named entity recognition (NER)
systems using a general clinical corpus annotated with disease and medication mentions. They were
then required to adapt these NER systems to a particular medical specialty, namely cardiology. In
addition, the MultiCardioNER task also explored the creation of clinical multilingual NER components
or cross-language adaptation of these systems for three languages: Spanish, English and Italian.
   The MultiCardioNER task relied on a previous resource exploited in a past shared task, called
DisTEMIST [18]. The DisTEMIST corpus is a collection of 1,000 clinical case reports covering a wide
range of specialties annotated for diseases by clinical experts. Furthermore, a previously unreleased
corpus called DrugTEMIST was published as part of the task. The DrugTEMIST corpus provides drug
or medication mention annotations for the same collection of clinical case reports as used for the
DisTEMIST dataset.
   For the adaptation to cardiology, we have constructed the CardioCCC corpus, a new dataset that
consists of manually selected cardiology clinical case reports showing similar characteristics as cardi-
ology discharge summaries. This resource was provided to participants to enable the exploration of
different clinical subdomain/specialty adaptation strategies and to benchmark the resulting systems.
To foster the generation of multilingual clinical NER corpora, DrugTEMIST and CardioCCC were
automatically translated from Spanish into both English and Italian. The Gold Standard drug mention
annotations were then mapped into both target languages and validated manually by clinical experts
(native speakers of English and Italian). The three corpora and the underlying annotation projection
process are described in more detail in Section 3.
   The evaluation process relied on the comparison of participating team predictions against the manual
annotations previously done by the clinical experts. Each team was allowed to submit up to 5 runs for
each subtrack and language. The evaluation process and metrics are reported in Section 2.3.

2.2. Subtracks
MultiCardioNER was structured into two different subtracks:

    • Subtrack 1 (CardioDis). This track focuses on the adaptation of disease recognition systems to
      the cardiology specialty in Spanish. Participants could use the DisTEMIST corpus [18] as a base
      training set, together with a new collection of cardiology-specific clinical case reports annotated
      with diseases (CardioCCC) that could be used to fine-tune or adapt their systems to cardiology
      case reports.
    • Subtrack 2 (MultiDrug). This subtrack focuses on the multilingual or cross-language adaptation
      (Spanish, English and Italian) of medication recognition systems, specifically for cardiology
      clinical case reports. For this track, participants could use the DrugTEMIST dataset as NER
      training resource. This corpus can be seen as a complementary dataset to the previously-released
      DisTEMIST, ProcTEMIST and SympTEMIST corpora, as it incorporates annotations of medications
      for the same document collection. To enable adaptation to cardiology, the CardioCCC corpus was
      annotated with medication mentions and divided into development and test subsets. While the
      original versions of both datasets were created using Spanish texts, a machine-translated version
      in English and Italian was revised by hand and annotated by clinical experts.

2.3. Evaluation
The task was divided into distinct phases: training and test set prediction (evaluation). During the
training phase, participants were provided with the DisTEMIST and DrugTEMIST datasets, as well as
a subset of the CardioCCC corpus made up of 258 documents. The second batch of the CardioCCC
collection was used as test set and released together with a larger background set to make sure that no
manual post-editing was carried out by the teams and that the submitted systems could scale up to
process larger data collections. These collections (test and background set) were released approximately
one month after the start of the training phase. Participants were given two weeks to generate predictions
for all documents. They were then evaluated using the Gold Standard annotations of the CardioCCC test
set, reserving the predictions for the background set to create a participants’ Silver Standard (discussed
in Section 3.4). It was not mandatory to submit results for all three languages.
   Both MultiCardioNER subtracks were evaluated using micro-averaged precision, recall and F1-score.
These metrics are calculated as follows:
Table 1
Results of the baseline system (vocabulary transfer) for the two MultiCardioNER subtracks
            Subtrack       Language                System Name             Precision   Recall    F1
            CardioDis       Spanish       DisTEMIST vocabulary transfer      0.5178    0.3681   0.4303
            MultiDrug       Spanish      DrugTEMIST vocabulary transfer      0.6366    0.7148   0.6734
            MultiDrug       English      DrugTEMIST vocabulary transfer      0.3317    0.7269   0.4556
            MultiDrug        Italian     DrugTEMIST vocabulary transfer      0.3320    0.6844   0.4471




                                                           True Positives
                                   Precision (P) =
                                                   True Positives + False Positives
                                                            True Positives
                                      Recall (R) =
                                                   True Positives + False Negatives
                                                   2 * (𝑃 * 𝑅)
                                   F1 score (F1) =
                                                    (𝑃 + 𝑅)

  As part of the task, an official MultiCardioNER evaluation library was released and is available on
GitHub1 . After the task results were released, the test set Gold Standard annotations were shared with
participating teams to enable them to perform extra experiments and facilitate error analysis of their
systems.

2.4. Baseline
To provide a baseline system for comparison, we used a simple vocabulary transfer approach that relied
on generating a gazetteer of entities from the training sets (DisTEMIST/DrugTEMIST corpora), and
carrying out dictionary look-up of these terms in the test set. Specifically, the system is a lexical lookup
approach that tries to find the annotated strings in both corpora within the cardiology test set. The
baseline results are shown in Table 1.


3. Corpus and resources
The MultiCardioNER task leverages an already-existing corpus, DisTEMIST, as well as two new releases,
DrugTEMIST and CardioCCC. DisTEMIST and DrugTEMIST share the same document collection,
which consists of clinical case reports from various clinical specialties such as oncology, infectious
diseases, urology and psychiatry. This collection of texts has also been used for the procedures corpus
MedProcNER/ProcTEMIST [19] and the signs and symptoms corpus SympTEMIST [20]. These corpora
could be considered complementary since they have been annotated by the same clinical experts using
the same methodology, which includes the creation of dedicated annotation guidelines. They were
released as part of previous shared tasks in an effort to promote the development and accessibility of
annotated resources for clinical information extraction in Spanish validated by clinical experts. Other
resources resulting from this initiative include PharmaCoNER [21], LivingNER [22], MEDDOPROF [23]
or MEDDOPLACE [24].
   The CardioCCC corpus consists of cardiology-specific clinical case reports. It includes annotations
for diseases and drugs created using the same guidelines as DisTEMIST and DrugTEMIST. Although
all three corpora were created originally in Spanish, the texts and annotations related to drugs were
translated into English and Italian and released for this task. Table 2 provides some statistics for the
different datasets that make up MultiCardioNER, which are explained in detail in this section. All
datasets described in this section are openly available on Zenodo2 .
1
    https://github.com/nlp4bia-bsc/multicardioner_evaluation_library
2
    https://zenodo.org/doi/10.5281/zenodo.10948354
Table 2
Statistics for the datasets provided for MultiCardioNER. “Annot.” stands for “annotations”, while “Chars”
stands for “characters”. Unique annotations refer to the number of distinct annotated strings after converting
all annotations to lowercase. The number of tokens has been calculated using the following spaCy models:
“es_core_news_sm”, “en_core_web_sm” and “it_core_news_sm”.
                                                                                       Mean          Mean
                                                                            Unique
    Dataset        Lang.    Entity     Docs Tokens        Chars   Annot.              Annot.         Annot.
                                                                            Annot.
                                                                                      Tokens         Chars
    DisTEMIST        ES     Diseases   1,000   406,137   2,335,968 10,664    6,739   3.20 ± 2.98   24.76 ± 18.89
    DrugTEMIST       ES      Drugs     1,000   406,137   2,335,968 2,778      925    1.19 ± 0.56   11.34 ± 4.46
                     EN      Drugs     1,000   404,194   2,230,631 2,814      875    1.25 ± 0.66   11.26 ± 0.52
                     IT      Drugs     1,000   421,251   2,393,002 2,808      893    1.25 ± 0.69   11.49 ± 4.73
    CardioCCC        ES     Diseases   508     568,297   3,215,774 18,232    7,692   3.32 ± 2.84   26.28 ± 19.06
                     ES      Drugs     508     568,297   3,215,774 4,227      755    1.19 ± 0.71   11.60 ± 5.25
                     EN      Drugs     508     576,772   3,114,833 4,231      734    1.21 ± 0.64   11.37 ± 4.74
                     IT      Drugs     508     595,332   3,345,466 4,385      752    1.23 ± 0.72   11.85 ± 5.25




Figure 1: Excerpt from the DisTEMIST corpus with various annotated diseases. Translation with annotated
entities in italics: “A 37-year-old woman diagnosed with AML (acute myeloblastic leukemia) in 2003 following a
spontaneous right hemopneumothorax that required surgery with evacuation of the hemothorax and resection of
bullous dystrophy. She was followed up on an outpatient basis without incident until 2009 when he presented
with chylous ascites and a large retroperitoneal cystic lymphangioma was detected on an abdominal computed
tomography (CT) scan. In February 2011 she was admitted for exertional dyspnea and extensive right pleural
effusion. Pleural fluid showed characteristics of chylothorax: [...]”.


3.1. DisTEMIST
DisTEMIST is a Gold Standard manually annotated corpus of disease mentions in Spanish clinical case
documents normalized or mapped to SNOMED CT concept identifiers. It consists of 1,000 clinical case
reports written in Spanish from miscellaneous medical specialties. Figure 1 shows an example of an
annotated document.
   The texts in the corpus were derived from SciELO (Scientific Electronic Library Online)3 , an electronic
library that contains publications from scientific journals. The texts were manually selected by clinical
experts so that their structure and content were clinically relevant and representative. The texts were
then pre-processed to extract the appropriate sections of the clinical cases and to remove embedded
figure references and citations to be as close as possible to real medical records. These texts were
originally released under the name SpaCCC (Spanish Clinical Case Corpus). As shown in Table 2, the
text collection includes a total of 406,137 tokens and 2,335,968 characters. In terms of annotations, the
corpus includes a total of 10,664 entities, out of which 6,739 are unique after converting them into
lowercase.
   The DisTEMIST corpus was annotated and standardized by two clinical experts from a Spanish

3
    http://www.scielo.org
tertiary hospital. The annotated mentions and their normalization were post-processed and revised
afterwards by a third physician. The annotations were created using the brat tool [25]. Annotation and
normalization guidelines were created specifically for this task. The annotation involved discussions
between physicians, particularly regarding complex mentions. This, together with multiple rounds of
inter-annotator agreement (IAA) through parallel annotation of a section of the corpus (around 20%),
resulted in an iterative refinement of the guidelines. After several rounds, a total IAA score of 82.3
(computed as the pairwise agreement between two independent annotators) for the disease mentions
was achieved.
   The result of this process is the DisTEMIST guidelines, openly available on Zenodo4 . The document
contains a total of 28 pages describing how to annotate diseases in clinical texts. There are a total of 52
rules divided into various types, such as general, positive or negative. There is also a set of rules specific
to oncology mentions that was added as the language used in clinical cases related to this specialty
proved to be more specific and harder to annotate. These are partially based on the CANTEMIST corpus
[26]. The guidelines also include a discussion of the task’s importance, a corpus characterization, basic
information about the task and the annotation process, as well as indications and resources for the
annotators. It is noteworthy that the DisTEMIST guidelines have been adapted to other domains, such
as social media [27].
   The DisTEMIST text documents are in plain text format with UTF-8 encoding. The annotations are
presented in two different stand-off versions. The first version includes the original annotation files
as outputted by brat [25]. These are .ann files, one for each text file, where each line represents an
annotation, including its label, its start and end position and its associated text. The second version is a
single tab-separated file (.tsv) which includes all annotations in the corpus. Similarly to the .ann files,
this version includes one annotation per row with an additional field for the corresponding filename.
   For MultiCardioNER, all 1,000 documents in the corpus are presented together. For anyone who wishes
to use the original train/test split of the corpus (consisting of 750 and 250 documents, respectively), we
advise downloading the original DisTEMIST Gold Standard5 to retrieve the list of filenames belonging to
each split. The original repository also includes the SNOMED CT mappings for the annotated mentions,
as well as some additional data, such as a background set of related clinical documents and a Silver
Standard of the corpus in 6 languages (English, Portuguese, Catalan, Italian, French and Romanian),
created using annotation projection. The annotation projection methodology is described in Section 3.2,
as well as in the original paper [18].

3.2. DrugTEMIST
DrugTEMIST is a collection of 1,000 clinical case reports from various clinical specialties annotated
with mentions of medications. Figure 2 shows an excerpt of an annotated document from the corpus.
   The corpus uses the same collection of texts as DisTEMIST, which is also shared by MedProcN-
ER/ProcTEMIST [19] and SympTEMIST [20]. Unlike those corpora, DrugTEMIST hadn’t been previously
released and is one of the novelties of the MultiCardioNER task. Again, the corpus includes a total of
406,137 tokens and 2,335,968 characters, as well as 2,778 annotated entities (925 unique after converting
them to lowercase).
   Similarly to the DisTEMIST corpus, dedicated annotation guidelines were written to define what
should be considered a medication and how to perform the annotations. These guidelines were created
and refined using the same methodology used for DisTEMIST, including thorough discussions between
physicians and the annotation of a sample of the corpus (around 20%). The final IAA of the corpus is
0.955. The DrugTEMIST annotation guidelines are also available in Zenodo6 . They contain 17 pages
and are quite similar to the DisTEMIST guidelines, with a total of 29 rules. The release format of the
corpus is the same as that of DisTEMIST.


4
  https://zenodo.org/doi/10.5281/zenodo.6458078
5
  https://zenodo.org/doi/10.5281/zenodo.6408476
6
  https://zenodo.org/doi/10.5281/zenodo.11065432
Figure 2: Excerpt from the DrugTEMIST corpus with various annotated medications. Translation with annotated
entities in italics: “An 82-year-old woman with a history of breast neoplasia treated with surgery and hormone
therapy 20 years ago, hypertensive cardiomyopathy in sinus rhythm, hypercholesterolemia and moderate chronic
hyponatremia around 133 mmol/L. She was treated with torasemide 5 mg/24h, isosorbide mononitrate 50 mg/24h,
acetylsalicylic acid 100 mg/24h, pravastatin 20 mg/24h, candesartan 32 mg/24h, hydrochlorothiazide 12.5 mg/24h,
atenolol 50 mg/24h and spironolactone 25 mg/24h”.


   The original Gold Standard of the corpus was created in Spanish. For the multilingual part of the
task, we created versions of the corpus in English and Italian using annotation projection techniques.
These two languages were chosen due to their relevance for other related projects and the availability of
clinical experts fluent in each language, who performed a manual revision of all documents to validate
the annotation and the quality of the translation. Specifically, the annotation projection methodology
consisted of the following steps:

   1. An automatic translation of the Spanish documents was carried out (for the previous DisTEMIST
      task) using high-quality commercial machine translation systems. In a separate step, the Gold
      Standard annotations were translated without context (i.e. as a plain list of strings).
   2. The translated annotations were next transferred into each document using a look-up system.
      For each document, only the annotations that existed in the original Gold Standard were looked
      up to prevent introducing false positives. The result of this step is an automatically annotated
      version of the corpus in each language, which could be considered a Silver Standard.
   3. In order for the corpus to be used as a Gold Standard, a manual revision was performed. Experts
      compared the original Spanish version of the documents with the version in English and Italian
      using brat’s side-by-side comparison mode. They were tasked with correcting existing and
      adding new mentions if necessary to make the annotation as close as possible to the original.
      Additionally, these experts were asked to provide alternative translations to annotated entities
      that were incorrectly translated.
   4. A post-processing step incorporated the alternative translations suggested by the annotators.
      These translations replaced the original annotated entity both in the text and in the annotation
      files.

   Statistics about the English and Italian versions of DrugTEMIST are also provided in Table 2. We
should underscore that the different versions of the corpus do not contain the exact same number
of annotations. This is mostly due to translation differences and errors introduced by the machine
translation system.

3.3. CardioCCC
CardioCCC (which stands for Cardiology Clinical Case Corpus) is a collection of 508 cardiology clinical
case reports. The documents were retrieved from open-access cardiology journals in Spanish. Within
these journals, we tried to manually locate clinical case reports that would have a similar structure to
real clinical health records. The candidates were then extracted and, in a similar fashion to the other
two corpora presented so far, pre-processed to keep only the relevant article sections and to remove
references to figures and tables. The cases were then revised by a clinical expert to confirm their validity.
Figure 3 shows a parallel example of the drug annotations in Spanish, English and Italian.
                                             (a) Example in English.




                                             (b) Example in Spanish.




                                              (c) Example in Italian.
Figure 3: Excerpt from the CardioCCC drug annotations in all three languages taken from the same document.


Table 3
Statistics for the two splits of the CardioCCC corpus. CardioCCC_dev refers to the first batch of the corpus,
which participants were allowed to use freely during the training phase. CardioCCC_test refers to the held-out
test set used for evaluation. “Annot.” stands for “annotations”, while “Chars” stands for “characters”. Unique
annotations refer to the number of distinct annotated strings after converting all annotations to lowercase. The
number of tokens has been calculated using the following spaCy models: “es_core_news_sm”, “en_core_web_sm”
and “it_core_news_sm”.
                                                                                       Mean          Mean
                                                                           Unique
Dataset            Lang. Entity Docs Tokens           Chars      Annot.               Annot.         Annot.
                                                                           Annot.
                                                                                      Tokens         Chars
CardioCCC_dev       ES    Diseases   258   315,047 1,777,279      10,348    4,749    3.34 ± 2.72 26.67 ± 18.47
                    ES     Drugs     258   315,047 1,777,279      2,510      526     1.21 ± 0.74 11.67 ± 5.34
                    EN     Drugs     258   319,289 1,718,585      2,510      513     1.22 ± 0.66 11.48 ± 4.85
                    IT     Drugs     258   330,291 1,848,888       2,585     520     1.23 ± 0.73 11.82 ± 5.31
CardioCCC_test      ES    Diseases   250   253,250 1,438,495      7,884     3,784    3.29 ± 3.00 25.76 ± 19.80
                    ES     Drugs     250   253,250 1,438,495      1,718      465     1.17 ± 0.66 11.51 ± 5.12
                    EN     Drugs     250   257,483 1,396,248      1,721      460     1.20 ± 0.61 11.21 ± 4.58
                    IT     Drugs     250   265,041 1,496,578      1,800      469     1.22 ± 0.71 11.89 ± 5.16


   The corpus contains annotations for diseases and drugs, which were created following the same
guidelines used for DisTEMIST and DrugTEMIST. The main annotator for CardioCCC was the same
clinical expert who did the final annotation and revision step for the other two corpora, which was a
big asset in accelerating the corpus annotation process. As with DrugTEMIST, the corpus’s texts were
translated from Spanish into English and Italian using machine translation. The Gold Standard drug
annotations were also transferred into English and Italian via annotation projection and revised by
clinical experts who are native speakers of each language.
   As explained in Section 2.3, CardioCCC was released in two batches: one for training/development
and another for evaluation. The statistics for these two parts are presented in Table 3, while Table 2
presents the statistics of the complete corpus. In terms of content, as shown by Table 2, the corpus
contains 568,297 tokens and 3,215,774 characters. Despite having about half the documents as the
SpaCCC corpus (i.e. the texts in DisTEMIST/DrugTEMIST), CardioCCC contains over 150,000 more
tokens and one million more characters, meaning the documents are quite longer. This is also reflected
in the number of annotations, with CardioCCC having around 8,000 more annotated diseases and 1,500
more drugs. Notably, despite the higher total number of annotations, CardioCCC contains fewer unique
drug mentions (which is calculated by converting all annotations to lowercase). This might be due to
the fact that in CardioCCC, drug mentions are usually more limited to cardiology-specific medications,
while in DrugTEMIST, there is a wider variety of medications mentioned due to the varied clinical
specialties it contains. As for the length of annotations themselves, all corpora seem to have a similar
distribution in terms of character and token length. The high standard deviation with respect to the
mean, especially for diseases, indicates that there’s a number of long annotations in the datasets.

3.4. Background set
In addition to the three annotated corpora, an additional dataset was released as a background set.
This dataset contains 7,625 text documents, both from the cardiology subdomain and other clinical
specialties. While most documents were originally written in Spanish, some of them were also originally
in English and Italian. All documents were translated to the other languages to have a comparable
background set in all three languages. Together with the background set, we release a tab-separated
values (.tsv) file that specifies the original language of each document and whether they belong to the
cardiology domain or not.
   As part of the task’s evaluation period, participants were asked to create predictions for diseases
and drugs using their systems. Their predictions were then used to create a Silver Standard, which we
release in three different versions:

   1. All mentions are kept, with the label name reflecting the team and run the prediction belongs to.
      This version inevitably includes many incorrect and redundant annotations.
   2. Only predictions that have some overlap with the predictions of a different run are used. The
      overlapping annotations are then merged under a single annotation and a new label name. This
      version should have a reduced number of incorrect annotations, although some of the “correct”
      annotations might have extension problems, such as being too short or too long.
   3. Only predictions that have a complete overlap with another prediction of a different run are used.
      This should, in theory, contain the highest number of correct annotations.

  Table 4 shows some basic statistics about the text documents included within the Silver Standard.
This new dataset can have multiple uses, such as bootstrapping manual annotations, system training
using semi-supervised learning techniques or errors and data analysis, amongst others.

Table 4
Statistics of the documents in the background set.
                            Language     Documents    Tokens      Characters
                             Spanish         7,625    3,863,801   22,066,533
                             English         7,625    3,857,831   21,130,044
                              Italian        7,625    4,015,920   22,782,246
    Table 5
    Overview of the teams that participated in MultiCardioNER. In the Affiliation column, A/I stands for
    academic or industry institution. In the Tasks column, C stands for the CardioDis subtrack and M for
    the MultiDrug subtrack.
     Team Name                                    Affiliation                              Tasks    Ref.
        BIT.UA                      IEETA, University of Aveiro, Portugal [A]                C      [28]
                       Technische Universität Wien, Austria & Spanish National Research
   DataScienceTUW                                                                           C/M     [29]
                                           Council (CSIC), Spain [A]
       Enigma                 OntoText, Bulgary & Sofia University, Bulgary [I/A]           C/M     [30]
        ICUE            University of Edinburgh, UK & Imperial College London, UK [A]        M      [31]
     NOVALINCS              NOVA School of Science And Technology, Portugal [A]             C/M     [32]
      PICUSLab                Università degli Studi di Napoli Federico II, Italy [A]        C      [33]
                        Siemens Advanta, Romania & Transilvania University of Brasov,
       Siemens                                                                              C/M     [34]
                                                 Romania [I/A]


4. Results
4.1. Participation overview
A total of 31 teams registered for the MultiCardioNER task, out of which 7 teams submitted at least
one run of their predictions. The participating teams originate from 8 different countries (some include
collaborations between teams from different countries), and except for one group from the industry,
the rest belong to academia. Table 5 shows the complete list of participating teams, along with their
affiliation and the reference to their task paper.
   As for the participation in each subtrack, 6 teams participated in the CardioDis subtrack, while 5
teams participated in the MultiDrug subtrack (with one of those teams participating only in the Spanish
part). Overall, a total of 70 runs were submitted, with each team allowed up to 5 runs per subtrack and
language: 20 for the CardioDis subtrack, 18 for the Spanish MultiDrug, 16 for the English MultiDrug
and 16 for the Italian MultiDrug.

4.2. System results
All in all, the top scores for each subtrack were:

    • Subtrack CardioDis. The team BIT.UA attained the top position with an ensemble of RoBERTa-
      based models (roberta-es-clinical-trials-ner) that also uses a multi-head-CRF approach [35]. Their
      runs integrated the provided datasets in different ways, with the highest scores achieved by the
      models that use both the DisTEMIST and CardioCCC data. Their best run achieved an F1-score of
      0.8199 and a recall of 0.8243. The team with the next best F1-score (0.8049) is Enigma, which uses a
      CLIN-X-ES model also fine-tuned on the DisTEMIST and CardioCCC data. Interestingly, the team
      PICUSLab achieves the best precision (0.8886) by a wide margin by combining the predictions of
      multiple models trained on different parts of the data (including an augmented version of the
      CardioCCC corpus) and then using string matching techniques to enhance the final predictions.
    • Subtrack MultiDrug. In Spanish, the best F1-score is achieved by the ICUE team (0.9277), who
      also achieved the best recall (0.9412). Meanwhile, in English and Italian, the winning team is
      Enigma, with an F1-score of 0.9223 and 0.8842, respectively.

  The results for the CardioDis subtrack are shown in Table 6, while the results for the MultiDrug
subtrack are presented in Table 7 for Spanish, Table 8 for English and Table 9 for Italian.

4.3. Methodologies
This section describes the methodologies used by each team, which are also summarized in Table 10.
Table 6
Results of the MultiCardioNER CardioDis subtrack, sorted by F1-score. The best result is bolded, and the
second-best is underlined.
      Team Name                         Run name                     Precision       Recall          F1
         BIT.UA                          run1-all-full                 0.8155        0.8243        0.8199
         BIT.UA                         run0-top5-full                  0.811        0.8181        0.8145
        Enigma                3-system-CLIN-X-ES-pretrained            0.8016        0.8082        0.8049
        Enigma                     2-system-CLIN-X-ES-14               0.8052        0.8007         0.803
       PICUSLab                         aug_fus_sub2                   0.7794         0.803         0.791
         BIT.UA                            run4-all                    0.7981        0.7827        0.7903
        Enigma                     1-system-CLIN-X-ES-12               0.7827        0.7938        0.7882
       PICUSLab                         aug_fus_sub1                   0.7346        0.7799        0.7566
         BIT.UA                          run3-all-val                  0.7544        0.7588        0.7566
         BIT.UA                         run2-best-val                   0.748        0.7542        0.7511
    DataScienceTUW                     run4-roberta-dg                 0.6565        0.7376        0.6947
    DataScienceTUW                run5-roberta-dg-windows              0.6546        0.7244        0.6877
        Siemens                           run1_SDR                     0.6758        0.6437        0.6593
       PICUSLab                       aug_fus_sm_sub2                  0.8919        0.4897        0.6323
    DataScienceTUW               run1_mdeberta-ct-mlm-dg               0.5928        0.6715        0.6297
       PICUSLab                       aug_fus_sm_sub1                  0.8886        0.4744        0.6185
    DataScienceTUW                    run2-mdeberta-ct                 0.5027        0.6884         0.581
    DataScienceTUW                  run3_mdeberta-ct-dg                 0.48         0.6773        0.5618
      NOVALINCS                1_bsc-bio-ehr-es_distemist_4            0.8018        0.3525        0.4897
      NOVALINCS                2_bsc-bio-ehr-es_distemist_1            0.8183        0.3398        0.4802


Table 7
Results of the MultiCardioNER MultiDrug subtrack in Spanish, sorted by F1-score. The best result is bolded, and
the second-best is underlined.
      Team Name                         Run name                     Precision       Recall          F1
         ICUE                           run2_single_pp                 0.9146        0.9412        0.9277
         ICUE                       run4_GPT_translation               0.9146        0.9412        0.9277
         ICUE                     run5_GPT_translation_all             0.9146        0.9412        0.9277
        Enigma                   3-system-SpanishRoBERTa                0.913        0.9348        0.9238
        Enigma                         1-system-XLMR                    0.904        0.9208        0.9123
        Enigma                     2-system-XLMR-filtering             0.9148        0.9005        0.9076
         ICUE                             run3_single                  0.8777        0.9272        0.9018
        Siemens                            run1_SMR                    0.8928        0.8778        0.8852
         ICUE                        run1_multilingual_pp              0.8287        0.9348        0.8786
        Enigma                 5-system-XLMR-filtering-dict2           0.7654        0.8871        0.8218
      NOVALINCS                3_bsc-bio-ehr-es_drugtemist_4           0.9242        0.4965         0.646
      NOVALINCS                4_bsc-bio-ehr-es_drugtemist_1           0.9076        0.4919         0.638
    DataScienceTUW              run3_roberta-ct-multilingual           0.8705        0.4342        0.5794
        Enigma                 4-system-XLMR-filtering-dict1           0.4351        0.7899        0.5611
    DataScienceTUW                   run5_roberta-ct-mlm               0.8421        0.3912        0.5342
    DataScienceTUW               run4_mdeberta_ct_mlm_dg               0.6815        0.3836        0.4909
    DataScienceTUW             run2_mdeberta-ct-multilingual           0.7647        0.3556        0.4855
    DataScienceTUW              run1_mdeberta-multilingual             0.3914        0.1531        0.2201


    • Team BIT.UA.
      For subtrack CardioDis, this team builds on some of their previous work, namely the Multi-Head-
      CRF approach [35], which introduces a Multi-Head Conditional Random Field (CRF) classifier
      on top of a multi-class NER system. Starting from the “roberta-es-clinical-trials-ner” pre-trained
Table 8
Results of the MultiCardioNER MultiDrug subtrack in English, sorted by F1-score. The best result is bolded, and
the second-best is underlined.
          Team Name                              Run name              Precision     Recall          F1
           Enigma                          3-system-BioLinkBERT         0.8981       0.9477        0.9223
            ICUE                               run2_single_pp           0.9086       0.9128        0.9107
            ICUE                           run4_GPT_translation         0.9086       0.9128        0.9107
           Enigma                              1-system-XLMR            0.8823       0.9233        0.9023
           Enigma                         2-system-XLMR-filtering       0.9031       0.8989         0.901
           Enigma                     5-system-XLMR-filtering-dict2     0.8698       0.9047        0.8869
            ICUE                                 run3_single            0.8734       0.8977        0.8854
            ICUE                            run1_multilingual_pp        0.8314       0.9343        0.8799
           Siemens                                run1_EMR              0.8685       0.8791        0.8738
           Enigma                     4-system-XLMR-filtering-dict1     0.8298        0.921         0.873
            ICUE                         run5_GPT_translation_all       0.8767       0.8635          0.87
       DataScienceTUW                  run3_roberta-ct-multilingual     0.8632       0.4364        0.5797
       DataScienceTUW                     run4-mdeberta-windows         0.7955       0.4317        0.5597
       DataScienceTUW                   run5-biobert-mlm-windows        0.6771        0.441        0.5341
       DataScienceTUW                 run2_mdeberta-ct-multilingual     0.8453       0.3777        0.5221
       DataScienceTUW                  run1_mdeberta-multilingual       0.5648       0.2481        0.3448


Table 9
Results of the MultiCardioNER MultiDrug subtrack in Italian, sorted by F1-score. The best result is bolded, and
the second-best is underlined.
          Team Name                              Run name              Precision     Recall          F1
           Enigma                           1-system-XLMR                0.884       0.8844        0.8842
           Enigma                  3-system-Italian-Spanish-RoBERTa     0.8723       0.8956        0.8838
           Enigma                       2-system-XLMR-filtering         0.9016       0.8606        0.8806
           Siemens                              run1_IMR                0.8891       0.8689        0.8789
            ICUE                         run4_GPT_translation           0.9114       0.8461        0.8776
            ICUE                       run5_GPT_translation_all         0.9114       0.8461        0.8776
            ICUE                             run2_single_pp             0.8186         0.9         0.8574
            ICUE                          run1_multilingual_pp          0.8139       0.8867        0.8487
            ICUE                               run3_single              0.7879       0.8894        0.8356
           Enigma                    4-system-XLMR-filtering-dict1      0.5693       0.8578        0.6844
           Enigma                    5-system-XLMR-filtering-dict2      0.5707       0.845         0.6813
       DataScienceTUW                 run3_roberta-ct-multilingual      0.8264       0.4206        0.5574
       DataScienceTUW                        run4-mdeberta              0.7481       0.3928        0.5151
       DataScienceTUW                       run5-biobit-mlm             0.7922       0.3517        0.4871
       DataScienceTUW                run2_mdeberta-ct-multilingual      0.7433       0.3394        0.4661
       DataScienceTUW                 run1_mdeberta-multilingual        0.5074       0.2094        0.2965


          model7 , they present 5 runs of ensembled models, with some runs consisting on models fine-tuned
          only with the DisTEMIST dataset and others with DisTEMIST plus CardioCCC. Their best run is
          an ensemble of 17 systems trained on both corpora, which achieves the highest F1-score of the
          subtrack (0.8199).
        • Team Data Science TUW.
          This team uses four main strategies throughout their experiments for both subtracks: pre-training
          via MLM (Masked Language Modelling), data augmentation, sliding windows with overlap and
          additional pre-training on general diseases and drugs using other corpora. The pre-trained models
          they use include the multilingual mDeBERTa [36, 37], the Spanish “roberta-es-clinical-trials-ner”,

7
    https://huggingface.co/lcampillos/roberta-es-clinical-trials-ner
Table 10
General overview of the approaches presented by participants for the MultiCardioNER task. “*TEMIST corpora”
refers to the joint version of the DisTEMIST, SympTEMIST, ProcTEMIST and DrugTEMIST corpora.
           Team              Task                                       Approaches
                                          Ensemble of RoBERTa models with multi-head CRF and differences in
          BIT.UA          CardioDis
                                         the data used for training (only DisTEMIST or DisTEMIST + CardioCCC)
       Data Science                        Transformer-based models with different pretraining settings, data
                          CardioDis
          TUW                                              augmentation and window sliding
                                             Multilingual and language-specific Transformers with different
                          MultiDrug
                                              pretraining settings, data augmentation and window sliding
                                         CLIN-X-ES model fine-tuned on the entire task data + custom clinical
          Enigma          CardioDis
                                                                          dataset
                                         Multilingual and language-specific Transformers fine-tuned on the entire
                          MultiDrug
                                                            task data + custom drug dictionary
                                            Multilingual and language-specific BERT models with re-training,
           ICUE           MultiDrug
                                                            post-processing rules + GPT 3.5
                                           RoBERTa model fine-tuned on the standalone DisTEMIST corpus vs.
       NOVALINCS          CardioDis
                                                               joint *TEMIST corpora
                                          RoBERTa model fine-tuned on the standalone DrugTEMIST corpus vs.
                          MultiDrug
                                                               joint *TEMIST corpora
                                          Ensemble of Transformer-based models trained on different datasets,
        PICUSLab          CardioDis       including an augmented version of CardioCCC + post-processing via
                                                                  string matching
          Siemens         CardioDis                      Fine-tuned general domain BERT model
                          MultiDrug             Fine-tuned language-specific general domain BERT models


         the English “biobert_chemical_ner”8 and the Italian BioBIT [38].
         An important note about this team’s results is that they had some problems with their submission
         that caused the overall low results. This is addressed in their system description, in which they
         re-evaluate their models with much better results, comparable to some of the task’s best.
       • Team Enigma.
         For subtrack CardioDis, team Enigma fine-tuned a CLIN-X-ES model [39] on the DisTEMIST and
         CardioCCC corpora for a different number of epochs. One of their runs further pre-trains the
         model using Spanish Wikipedia pages and datasets from different challenges, achieving them a
         spot in the subtrack’s top three F1-scores (0.8049).
         For subtrack MultiDrug, the team uses a combination of different models, including a multilingual
         XLM-RoBERTa [40] and language-specific models such as a Spanish RoBERTa [41] (which they also
         use for Italian) and BioLinkBERT for English [42]. Their first run, which uses the multilingual XLM-
         RoBERTa, pre-trains the model on a custom multi-lingual dataset (including biomedical challenge
         data, European drug description data, Wikipedia) and then fine-tuned for token classification on
         all data for all languages. For Italian, this approach achieves them the highest F1-score of the
         Italian part of the subtrack (0.8842).
         Their second run uses the same system but adds a classifier before it, which determines if there
         are any drugs in the sentence. For Spanish and English, their best run is the third one, which uses
         a language-specific model. This is not the case, however, for their third Italian run, which uses a
         Spanish model pre-trained on Italian data. Another interesting contribution by this team is the
         combination of neural systems and drug dictionaries obtained from resources such as DrugBank,
         ATC, DrugCentral or the NIHS. The two runs that use this approach achieve very good results,
         although not as good as their other ones.
8
    https://huggingface.co/alvaroalon2/biobert_chemical_ner
     • Team ICUE.
       For the MultiDrug subtrack, this team compares the effectiveness of multilingual and monolingual
       BERT models. They also experiment with the inclusion of post-processing rules (specifically for
       composite drug mentions in Spanish), as well as with using Large Language Models (LLMs) such
       as GPT-3.5 [43] to translate predictions in Spanish to the other two languages. Their methodology
       achieves very good results, especially when they use monolingual models. In Spanish, they
       achieve the best F1-score (0.9277). It is noteworthy that some of their runs in the results table are
       repeated since they presented the same system with changes only for some languages.
       Team ICUE also includes some additional experiments in their system description paper, such as
       using GPT-3.5 and LLaMA [44] for entity recognition with competitive results.
     • Team NOVALINCS.
       For CardioDis, this team fine-tunes the “bsc-bio-ehr-es” pre-trained RoBERTa9 using the Dis-
       TEMIST corpus. They prepared two runs: one in which they only use the DisTEMIST annotations
       and another in which they also incorporate the other 3 entities from the complementary corpora
       (that is, procedures from MedProcNER/ProcTEMIST, symptoms from SympTEMIST and medica-
       tions from DrugTEMIST). For MultiDrug, they only participated in the Spanish part using the
       same methodology, exchanging DisTEMIST with DrugTEMIST. Their overall results for both
       tasks are remarkable for their high precision and low recall, which may indicate the difficulty of
       the systems to adapt to the cardiology subdomain using only the general clinical domain data.
     • Team PICUSLab.
       For the CardioDis subtrack, this team employs an ensemble transfer learning strategy. They train
       different models on DisTEMIST, CardioCCC and an augmented version of CardioCCC (created
       with the help of sentence similarity techniques and a gazetteer), and then fuse the predictions
       of the different models. To further improve their predictions, they use string matching to post-
       process them. Their best run earns them a spot in the subtrack’s top 5 with an F1-score of
       0.791.
     • Team Siemens.
       This team participated in both CardioDis and MultiDrug with the same methodology. They
       use general domain BERT models (“bert-spanish-cased-finetuned-ner“10 , “bert-base-NER“11 and
       “bert-italian-finetuned-ner“12 ) and fine-tune them for multi-label token classification using the
       different MultiCardioNER datasets. Despite not using clinical models, their results are quite
       good, especially for the MultiDrug subtrack (e.g. 0.8789 F1-score in the Italian part). In their
       overview paper, they also perform additional experiments that were not evaluated during the
       task’s evaluation phase.


5. Discussion
Comparison with previous tasks.
   MultiCardioNER is a novel task built upon the foundation of previous tasks and resources. In recent
years, tasks such as DisTEMIST [18], PharmaCoNER [21] or MedProcNER [19] have provided the
Spanish NLP community with a variety of corpora for the recognition (and normalization) of named
entities in clinical texts. These corpora have progressively become reference corpora used to benchmark
and model pre-training efforts [39, 45, 46, 47, 48, 49]. MultiCardioNER is different from these previous
tasks in that it uses data from a single clinical specialty, rather than a general medical dataset. The
CardioCCC corpus could become a reference for cardiology and subdomain adaptation in clinical NLP
in Spanish. The corpus is expected to expand with the addition of case reports, more entity types (such
as procedures and symptoms), and more languages.

9
 https://huggingface.co/PlanTL-GOB-ES/bsc-bio-ehr-es
10
   https://huggingface.co/mrm8488/bert-spanish-cased-finetuned-ner
11
   https://huggingface.co/dslim/bert-base-NER
12
   https://huggingface.co/nickprock/bert-italian-finetuned-ner
   Subdomain adaptation is a major goal of MultiCardioNER. The task’s results indicate the importance
of using subdomain data to build systems with specific application fields. All top-performing systems
incorporate the released 258 documents from the CardioCCC corpus. In contrast, participants that only
use the DisTEMIST and DrugTEMIST corpora (consisting of clinical case reports from various specialties)
achieve high precision but fail to recall, thus obtaining a comparatively lower F1-score. This suggests
that, while these systems are able to retrieve many clinical entities correctly (i.e. high precision), they
fail to recover concepts specific to the cardiology subdomain (i.e. low recall). Furthermore, comparing
the results of the DisTEMIST shared task [18] with the CardioDis subtrack, the overall results are
somewhat better in the latter task: DisTEMIST’s winning team obtained an F1-score of 0.77, while the
winning team of MultiCardioNER obtained an F1 of 0.81. This might point to the importance of using
specialty-specific data, even within very similar clinical domains.
   We should underline that compared with DisTEMIST, this task offers a higher volume of training
data. While there seems to be a positive correlation with the use of subdomain-specific data, it
remains a question whether these improvements can actually be attributed to subdomain adaptation, to
differences in each of the tasks’ test sets, or to simply having more data.

   Similarity between the general domain and the cardiology corpora.
   Given the task’s focus on subdomain adaptation, and in order to further characterise the cardiology
and SpaCCC datasets (i.e. the DisTEMIST and DrugTEMIST texts) of the shared task, a comparison
analysis was conducted between these clinical case reports and documents belonging to other medical
disciplines. These documents consist of a collection of clinical cases categorised into 22 different
specialities with varying text structures and content, including oncology, COVID-specific reports,
primary health care, neurology, etc. The data for the other specialties was extracted using the same
methodology as for the CardioCCC (cardiology) corpus (explained in Section 3.3).
   For the analysis, we tried to create a mathematical representation of the different document spe-
cialties and their subsequent visualisation in a two-dimensional space. To this purpose, the document
embeddings were extracted using the pre-trained language model “roberta-base-biomedical-clinical-es”
(RoBERTa-based and trained on a large Spanish biomedical corpus from different sources), resulting in
tensors of 𝑛 × 𝑚 dimensions, where 𝑛 is the number of sentences in the document and 𝑚 is the size
of the language model (768 for the RoBERTa model). Subsequently, a vector composition technique
was employed to process the extracted document embeddings, as described in the work of Amigó et al.
[50]. This involved utilising the proposed generalised composition function in Amigó et al. [50] and
illustrated in Equation 1. In this expression, the first component determines the vector direction of the
sum of two vectors (𝑣⃗1 and 𝑣⃗2 ), while the second component represents its magnitude, which depends
on the norm of single vectors and their inner product. By applying this function to pairs of successive
sentences in a document and representing them as vectors, we are able to compute and represent each
document as a single vector (embedding).
   In this study we implemented two different composition functions derived from Equation 1, the
summation (𝐹𝑠𝑢𝑚 ), obtained when the constants 𝜆 and 𝜇 are equal to 1 and −2 respectively, and 𝐹𝑖𝑛𝑑 ,
a particularization of Equation 1 when 𝜆 is equals to 1 and 𝜇 to 0.

                                           𝑣⃗1 + 𝑣⃗2
                                                        √︁
                      𝐹𝜆,𝜇 (𝑣⃗1 , 𝑣⃗2 ) =              · 𝜆(‖𝑣⃗1 2 ‖ + ‖𝑣⃗2 2 ‖) − 𝜇⟨𝑣⃗1 , 𝑣⃗2 ⟩        (1)
                                          ‖𝑣⃗1 + 𝑣⃗2 ‖
   Following the document vector representation and the composition function technique, we imple-
mented a t-Distributed Stochastic Neighbour Embedding (t-SNE) algorithm with a perplexity of 30
and a maximum number of iterations of 800 to reduce the dimensionality of the document embed-
dings. This statistical method enables the visualisation of high-dimensional document embeddings in
lower-dimensional spaces, in this case, two dimensions.
   Figures 4 and 5 illustrate the scatter plots generated by the applied methodology, utilising the two
composition functions previously mentioned, 𝐹𝑠𝑢𝑚 and 𝐹𝑖𝑛𝑑 respectively. Both figures reveal distinct
clustering patterns depending on the specialty. Documents belonging to specific specialties form a
well-defined cluster (see cardiology i.e. CardioCCC in black), highlighting the fact that each of them
Figure 4: Document embeddings representation per each discipline after reduction of their dimensionality to
2-dimensions by applying the t-SNE algorithm and using 𝐹𝑠𝑢𝑚 as the composition function.




Figure 5: Document embeddings representation per each discipline after reduction of their dimensionality to
2-dimensions by applying the t-SNE algorithm and using 𝐹𝑖𝑛𝑑 as the composition function.


possesses unique features in terms of content and structure. In contrast, documents from the SpaCCC
corpus (red points) are scattered across the plot, reflecting their diverse nature. This is due to the fact
that they cover a wide range of medical disciplines, such as cardiology (CardioCCC), oncology, urology,
pneumology or infectious diseases, among many others.

   Future work and conclusions.
   There is a pressing need to promote the development of annotated datasets to generate automatic
clinical concept detection tools, not only for a single language but for several languages, following
comparable annotation criteria and consistent results across multiple languages. Due to the complexity
and considerable workload associated with the manual corpus construction process of clinical content,
the use of creative solutions such as neural translation and annotation projection strategies might provide
an alternative solution to traditional corpus construction attempts. The results of the MultiCardioNER
task indicate that it is feasible to create multilingual clinical corpora and use them to train and generate
very competitive clinical NER systems with comparable results across several languages.
   Moreover, an adaptation of clinical NLP components to specific medical specialties can improve the
quality of the resulting systems for real-world scenarios. Typically clinical NLP application scenarios
or use cases focus on content related to a particular medical discipline, disease or patient type. In this
regard, the MultiCardioNER task also provides useful insights on how to adapt general-purpose clinical
NLP systems to the characteristics of a medical specialty of interest.
   We foresee that the results, resources, and strategies generated through the MultiCardioNER task
(both by organizers and participants) might potentially promote also the creation of clinical NLP
resources beyond the three chosen languages covered in this track. The MultiCardioNER silver standard
corpus of predictions for Spanish, English and Italian could also constitute a valuable resource for data
augmentation or corpus construction by manually validating the generated system predictions.
   The presented annotation projection strategy obviously relies on the sufficient quality of the used
medical translation systems. Therefore, systematic efforts to evaluate the quality of neural medi-
cal machine translation systems are critical. Initiatives like the Workshop on Machine Translation
(WMT) Biomedical Translation shared task has provided insights on the quality and potential of neural
translation technologies adapted to translate healthcare documents [51, 52].


Acknowledgments
The MultiCardioNER track was funded by Spanish and European projects such as DataTools4Heart
(Grant Agreement No. 101057849), AI4HF (Grant Agreement No. 101080430), BARITONE (Proyec-
tos de Transición Ecológica y Transición Digital 2021. Expediente Nº TED2021-129974B-C21) and
AI4ProfHealth (PID2020-119266RA-I00 MICIU/AEI/10.13039/501100011033).
   Google was a proud sponsor of the BioASQ Challenge in 2023. Ovid is also sponsoring this edition
of BioASQ. The twelfth edition of BioASQ is also sponsored by Elsevier. Atypon Systems Inc. is also
sponsoring this edition of BioASQ.


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