\documentclass[10pt]{article}

\usepackage{fullpage}
\usepackage{setspace}
\usepackage{parskip}
\usepackage{titlesec}
\usepackage[section]{placeins}
\usepackage{xcolor}
\usepackage{breakcites}
\usepackage{lineno}
\usepackage{hyphenat}





\PassOptionsToPackage{hyphens}{url}
\usepackage[colorlinks = true,
            linkcolor = blue,
            urlcolor  = blue,
            citecolor = blue,
            anchorcolor = blue]{hyperref}
\usepackage{etoolbox}
\makeatletter
\patchcmd\@combinedblfloats{\box\@outputbox}{\unvbox\@outputbox}{}{%
  \errmessage{\noexpand\@combinedblfloats could not be patched}%
}%
\makeatother


\usepackage{natbib}




\renewenvironment{abstract}
  {{\bfseries\noindent{\abstractname}\par\nobreak}\footnotesize}
  {\bigskip}

\titlespacing{\section}{0pt}{*3}{*1}
\titlespacing{\subsection}{0pt}{*2}{*0.5}
\titlespacing{\subsubsection}{0pt}{*1.5}{0pt}


\usepackage{authblk}


\usepackage{graphicx}
\usepackage[space]{grffile}
\usepackage{latexsym}
\usepackage{textcomp}
\usepackage{longtable}
\usepackage{tabulary}
\usepackage{booktabs,array,multirow}
\usepackage{amsfonts,amsmath,amssymb}
\providecommand\citet{\cite}
\providecommand\citep{\cite}
\providecommand\citealt{\cite}
% You can conditionalize code for latexml or normal latex using this.
\newif\iflatexml\latexmlfalse
\providecommand{\tightlist}{\setlength{\itemsep}{0pt}\setlength{\parskip}{0pt}}%

\AtBeginDocument{\DeclareGraphicsExtensions{.pdf,.PDF,.eps,.EPS,.png,.PNG,.tif,.TIF,.jpg,.JPG,.jpeg,.JPEG}}

\usepackage[utf8]{inputenc}
\usepackage[ngerman,english]{babel}



\usepackage{float}








\begin{document}

\title{GLOBAL IMPLEMENTATION OF THE WORLD HEALTH ORGANIZATION'S INTERNATIONAL
CLASSIFICATION OF DISEASES (ICD)-11: THE ALLERGIC AND HYPERSENSITIVITY
CONDITIONS MODEL}



\author[1]{LUCIANA TANNO}%
\author[2]{Robert Chalmers}%
\author[2]{Robert Jakob}%
\author[2]{Nenad Kostanjsek}%
\author[1]{Ana Luiza Bierrenbach}%
\author[3]{Bryan Martin}%
\author[4]{Nicolas Molinari}%
\author[5]{Isabella Annesi}%
\author[6]{Nikolaos Papadopoulos}%
\author[7]{Mario Sanchez-Borges}%
\author[8]{Lanny Rosenwasser}%
\author[9]{Ignacio J Ansotegui}%
\author[10]{Motohiro Ebisawa}%
\author[11]{Juan Carlos Sisul}%
\author[12]{Edgardo Jares}%
\author[13]{Maximiliano Gómez}%
\author[14]{Ioana Agache}%
\author[15]{Antonella Muraro}%
\author[16]{Gary Wong}%
\author[17]{Francis Thien}%
\author[18]{Ruby Pawankar}%
\author[19]{Tood Mahr}%
\author[20]{JAMES Sublett}%
\author[21]{David Lang}%
\author[22]{Thomas Casale}%
\author[23]{Pascal Demoly}%
\affil[1]{Hospital Sírio Libanês}%
\affil[2]{World Health Organization}%
\affil[3]{Columbus State University}%
\affil[4]{service DIM}%
\affil[5]{EPAR U707 INSERM}%
\affil[6]{Second Pediatric Clinic}%
\affil[7]{Centro Medico-Docente La Trinidad}%
\affil[8]{Children's Mercy Hospitals and Clinics}%
\affil[9]{Hospital Quironsalud Bizkaia}%
\affil[10]{National Hospital Organization, Sagamihara National Hospital}%
\affil[11]{Latin American Society of Allergy, Asthma and Immunology}%
\affil[12]{LIBRA Foundation and CMP SA }%
\affil[13]{Fundación Ayre }%
\affil[14]{Transylvania University of Brasov}%
\affil[15]{Padua General University Hospital}%
\affil[16]{Chinese University of Hong Kong}%
\affil[17]{Monash University}%
\affil[18]{Nippon Medical School}%
\affil[19]{Gundersen Health System in La Crosse}%
\affil[20]{UNIVERSITY OF LOUISVILLE SCHOOL OF MEDICINE}%
\affil[21]{Department of Allergy}%
\affil[22]{University of South Florida}%
\affil[23]{University Hospital of Montpellier}%


\vspace{-1em}



  
  \date{March 14, 2025}


\begingroup
\let\center\flushleft
\let\endcenter\endflushleft
\maketitle
\endgroup





\selectlanguage{english}
\begin{abstract}
The International Classification of Diseases (ICD) provides a common
language for use worldwide as a diagnostic and classification tool for
epidemiology, clinical purposes and health management. Since its first
edition, the ICD has maintained a framework distributing conditions
according to topography, with the result that some complex conditions,
such as allergies and hypersensitivity disorders (A/H) including
anaphylaxis, have been poorly represented. The change in hierarchy in
ICD-11 permitted the construction of the pioneer section addressed to
A/H, which may result in more accurate mortality and morbidity
statistics, including more accurate accounting for mortality due to
anaphylaxis, strengthen classification, terminology and definitions. The
ICD-11 was presented and adopted by the 72nd World Health Assembly in
May 2019 and the implementation is ongoing worldwide. We here present
the outcomes from an online survey undertaken to reach out the allergy
community worldwide in order to peer review the terminology,
classification and definitions of A/H introduced into ICD-11 and to
support their global implementation. Data are presented here for 406
respondents from 74 countries. All of the sub-sections of the new A/H
section of the ICD-11 had been considered with good accuracy by the
majority of respondents. We believe that, in addition to help during the
implementation phase, all the comments provided will help to improve the
A/H classification and to increase awareness by different disciplines of
what actions are needed to ensure more accurate epidemiological data and
better clinical management of A/H patients.%
\end{abstract}%



\sloppy


GLOBAL IMPLEMENTATION OF THE WORLD HEALTH ORGANIZATION'S INTERNATIONAL
CLASSIFICATION OF DISEASES (ICD)-11: THE ALLERGIC AND HYPERSENSITIVITY
CONDITIONS MODEL

Luciana Kase Tanno \textsuperscript{1,2,3,4,5*} , Robert
Chalmers\textsuperscript{5,6}, Robert Jacob \textsuperscript{7}, Nenad
Kostanjsek \textsuperscript{7}, Ana Luiza
Bierrenbach\textsuperscript{1,8}, Bryan Martin \textsuperscript{9},
Nicolas Molinari \textsuperscript{10}, Isabella
Annesi-Maesano\textsuperscript{3}, Nikolaos G.
Papadopoulos\textsuperscript{11}, Mario Sanchez-Borges
\textsuperscript{12} , Lanny J Rosenwasser\textsuperscript{13}, Ignacio
Ansontegui\textsuperscript{14}, Motohiro Ebisawa\textsuperscript{15},
Juan Carlos Sisul\textsuperscript{16}, Edgardo
Jares\textsuperscript{17}, Maximiliano Gomez\textsuperscript{18}, Ioana
Agache\textsuperscript{19}, Antonella Muraro\textsuperscript{20}, Gary
WK Wong \textsuperscript{21}, Francis Thien\textsuperscript{22,23}, Ruby
Pawankar\textsuperscript{24}, Todd A. Mahr \textsuperscript{25}, James
L. Sublett\textsuperscript{26}, David M Lang\textsuperscript{27}, Thomas
Casale\textsuperscript{28}, Pascal Demoly \textsuperscript{2,3,4} , and
on behalf of the Joint Allergy Academies**

1 Hospital S\selectlanguage{ngerman}írio-Libanês

2 University Hospital of Montpellier, Montpellier, France

3 Sorbonne Université, INSERM UMR-S 1136, IPLESP, Equipe EPAR, 75013,
Paris, France

4 WHO Collaborating Centre on Scientific Classification Support,
Montpellier, France

5 ICD-11 Medical and Scientific Advisory Committee, WHO, Geneva

6 Centre for Dermatology, University of Manchester, UK

7 Classifications, Terminologies and Standards, World Health
Organization, Geneva, Switzerland.

8 Sanas Epidemiology and Research, São Paulo, and Teaching Research
Institute (IEP), Hospital Sírio Libanês, São Paulo, Brazil

9 Medicine and Pediatrics, The Ohio State University in Columbus, Ohio,
USA

10 IMAG UMR 5149, DIM CHRU de Montpellier, France

11 Centre for Paediatrics and Child Health , Institute of Human
Development, University of Manchester, United Kingdon and Department of
Allergy, 2nd Pediatric Clinic, University of Athens, Athens, Greece

12 Allergy and Clinical Immunology Department, Centro Medico Docente La
Trinidad, Caracas, Venezuela

13 Department of Pediatrics, Division of Immunology Research, Children's
Mercy Hospitals \& Clinics, Kansas City, MO 64108, USA

14 Department of Allergy and Immunology, Hospital Quirónsalud Bizkaia
Erandio, Bilbao, Spain

15 Clinical Research Center for Allergy and Rheumatology, Sagamihara
National Hospital, Japan

16 Past President of the Latinalerican Society of Allergy, Asthma and
Immunology and fellow of the American College of Allergy, Asthma and
Immunology, Paraguay

17 LIBRA Foundation and CMP SA Buenos Aires, Argentina

18 Research \& Education, Fundación Ayre. Allergy \& Asthma Unit,
Hospital San Bernardo. Salta, Catholic University of Salta, Argentina.

19 Transylvania University, Brasov, Romania

20 Food Allergy Referral Centre Veneto Region, Department of Women and
Child Health, Padua General University Hospital, Padua, Italy

21 Department of Pediatrics, Chinese University of Hong Kong, Hong Kong,
China

22 Faculty of Medicine, Nursing and Health Sciences, Monash University,
Clayton, Vic Australia

23 Department of Respiratory Medicine, Eastern Health, Vic, Boxhill,
Australia

24 Department of Pediatrics, Nippon Medical School, Tokyo, Japan.

25 Pediatric allergy and clinical immunology, Gundersen Health System in
La Crosse, USA

26 Managing Partner, Family Allergy \& Asthma; Clinical Professor,
Section of Allergy \& Immunology, Department of Pediatrics, University
of Louisville School of Medicine, Louisville, KY USA

27 Department of Allergy and Clinical Immunology, Respiratory Institute
, Cleveland Clinic, Ohio, USA

28 Morsani College of Medicine, University of South Florida, Tampa, FL,
USA

* Corresponding author: Luciana Kase Tanno MD, PhD, Division of Allergy,
Department of Pulmonology, Hôpital Arnaud de Villeneuve, University
Hospital of Montpellier, 371, av. du Doyen Gaston Giraud - 34295,
Montpellier cedex 5, France. Tel.: +33 467336107 Fax: +33 467633645

E-mail: luciana.tanno@gmail.com

** Joint Allergy Academies: American Academy of Allergy Asthma and
Immunology (AAAAI), European Academy of Allergy and Clinical Immunology
(EAACI), World Allergy Organization (WAO), American College of Allergy
Asthma and Immunology (ACAAI), Asia Pacific Association of Allergy,
Asthma and Clinical Immunology (APAAACI), Asia Pacific Academy of
Pediatric Allergy, Respirology \& Immunology (APAPARI), Latin American
Society of Allergy, Asthma and Immunology (SLAAI)

ABSTRACT

The International Classification of Diseases (ICD) provides a common
language for use worldwide as a diagnostic and classification tool for
epidemiology, clinical purposes and health management. Since its first
edition, the ICD has maintained a framework distributing conditions
according to topography, with the result that some complex conditions,
such as allergies and hypersensitivity disorders (A/H) including
anaphylaxis, have been poorly represented.

The change in hierarchy in ICD-11 permitted the construction of the
pioneer section addressed to A/H, which may result in more accurate
mortality and morbidity statistics, including more accurate accounting
for mortality due to anaphylaxis, strengthen classification, terminology
and definitions. The ICD-11 was presented and adopted by the
72\textsuperscript{nd} World Health Assembly in May 2019 and the
implementation is ongoing worldwide.

We here present the outcomes from an online survey undertaken to reach
out the allergy community worldwide in order to peer review the
terminology, classification and definitions of A/H introduced into
ICD-11 and to support their global implementation. Data are presented
here for 406 respondents from 74 countries. All of the sub-sections of
the new A/H section of the ICD-11 had been considered with good accuracy
by the majority of respondents.

We believe that, in addition to help during the implementation phase,
all the comments provided will help to improve the A/H classification
and to increase awareness by different disciplines of what actions are
needed to ensure more accurate epidemiological data and better clinical
management of A/H patients.

KEY WORDS: allergy, classification, definition, hypersensitivity,
International Classification of Diseases, implementation, terminology,
World Health Organization

THE SCOPE OF THE PROBLEM

\emph{The World Health Organization International Classification of
Diseases (ICD)}

The fields of health terminology, classification, ontology, and related
information models have evolved dramatically over the last 25 years (1)
and the increasing demands and uses of information has also transformed
the process of coding. A standard registry of morbidity and mortality
data provides health information for statistics and epidemiology, health
care management, allocation of resources, monitoring and evaluation of
research, and for disease prevention and treatment. This information
need has given rise to a process of coding, whereby words describing
medical conditions are translated into codes (2).

The International Classification of Diseases (ICD) is maintained by the
World Health Organization (WHO) and provides a common language for use
worldwide as a diagnostic and classification tool for epidemiology,
clinical purposes and health management. It enables the analysis of the
general health situation of different population groups and provides
data on the key problems to be managed. It is used to classify diseases
registries for many types of health and administrative purposes
including death certificates and electronic health care records. In
addition to enabling the storage and retrieval of diagnostic information
for clinical, epidemiological and quality purposes, including the needs
of payers and Health Technology Assessment bodies, these reported data
also provide the basis for compilation of national mortality and
morbidity statistics (MMS) by WHO Member States (2,3).

The first edition of the ICD was published in 1893 (4). This
classification distinguished between systemic diseases and those
localized to a particular organ or anatomical site (5). The ICD has thus
far maintained a similar framework, distributing conditions according to
topography (5), with the result that some complex conditions, such as
allergies including anaphylaxis, have been poorly represented.

The ICD has been periodically revised, with most countries now using the
tenth revision (ICD-10) or national adaptations thereof (3). It is used
by more than 100 countries, is available in 43 different languages and
is the tool used for allocating about 70\% of the world's health
expenditure. In the US alone this amounted in 2017 to USD \$ 3.5
trillions according to the National Center for Health Statistics (6-8).
Therefore, modification of the ICD framework has the potential to have
an impact on health financing and economics. On the other hand, the
misclassification or underrepresentation of specific disorders in this
global classification system can lead to lack of visibility, investment
and public health action, as proved for allergic and hypersensitivity
conditions (9,10).

\emph{The need for a better representation of allergic and
hypersensitivity conditions in the ICD}

Originally perceived as secondary disorders by most of health
professionals, A/H represent one of the fastest growing group of
conditions worldwide and have become a \textbf{major public health
problem} . It is estimated that more than 150 million Europeans and over
25 to 30\% of the world's population are affected by these conditions
(11,12). The Asthma and Allergy Foundation states that allergy affects
one in five citizens (6) and accounts for more than 17 million
outpatient office visits per year in the Unites States of America alone
(7). The estimated annual cost of allergies is nearly \$7 billions (6).
Allergies now represent the fourth most common chronic disease category
in the world (6,12). WHO predicts that in 2050, 1 in 2 people in the
world will suffer from allergies with a steady increase, especially in
industrialized countries. In France, the number of people suffering from
an allergy has doubled in 20 years, especially among children and
adolescents (8,11-13). Proper documentation, classification and coding
of patients' allergy information is vital to support their care, safety,
and education. However, \textbf{A/H} \textbf{have never been well
classified and coded in the ICD} . The current classification framework,
ICD-10, presents conceptual and operational failures for A/H, as
demonstrated and published in Brazil for anaphylaxis (10).

\emph{The ICD-11 revision}

In development since 2007, ICD-11 is intended not only to rectify
deficiencies in ICD-10 and to incorporate changes demanded by scientific
advances, but also to take advantage of the revolution in electronic
data handling since the publication of ICD-10 a quarter of a century
ago.

ICD-11 is regarded as a suite of classifications, which is based on a
detailed and comprehensive polyhierarchical web-like foundation in which
any single disease entity may be represented in more than one location
(3). The innovatory electronic authoring and browsing platforms
developed for the ICD Revision Project enabled ICD-11 to be assembled
and refined in a sophisticated manner including metadata such as
definitions, synonyms and causal mechanisms for each concept and support
for a complex polyhierarchical structure.

From this foundation may be extracted any number of traditional tabular
lists, which differ from the foundation in that a single entity may
appear in only one location as in ICD-10. This also permitted the
construction of a range of specialist classifications in which the
detail contained in the foundation is retained but which can be linked
to ICD-11 (14).

THE WORLD NEEDS BETTER HEALTH DATA

\emph{The Allergy in ICD-11 initiative}

Over the past 7 years, a detailed action plan was developed and
implemented under the \emph{ALLERGY in ICD-11} \emph{initiative} (led by
LKT and PD) with the aim of creating a more appropriate classification
for A/H conditions in this new edition of ICD. Through its academic work
in providing scientific and technical evidence, it has been possible to
get in touch with the WHO and its representatives of the need for change
in the representation of A/H disorders in the
11\textsuperscript{th}revision. The continuing close collaboration
between our group and WHO has the backing of 6 international regional
allergy academies, named Joint Allergy Academies. (15). The core Allergy
in ICD-11 operational team (LKT and PD) is an independent non-profit
group working for the Allergy specialty worldwide and represents the
Joint Allergy Academies into the ICD-11 and other WHO classifications.

The main outcome of this process has been the construction of the
pioneering \emph{Allergic and hypersensitivity conditions}section within
the newly created chapter, \emph{Disorders of the Immune System,} which
has been incorporated into ICD-11. All the evidence-based academic
process has been documented in peer-reviewed publications (2,9,10,13,
15-40).

The new framework addressing A/H conditions underwent extensive
field-testing (30) and quality assurance (25-27), demonstrating that use
of the ICD-11 MMS resulted in a clear increase in the frequency of
accurate coding for these conditions when compared with ICD-10.
Furthermore, ICD-11 enables diagnoses to be linked to a range of
parameters by the addition of one or more ``extensions'', classified
under the ``Extension codes'' X chapter in a process termed
post-coordination (14). WHO has been promoting this classification
strategy in which a stem entity (\emph{e.g.} Anaphylaxis) can be more
fully defined by linking it to a range of different value sets including
severity, anatomical location and causal agent.

We were also able to enhance changes in the WHO mortality coding rules
by including anaphylaxis as underlying cause of death in official death
certificates, which will contribute to more accurate mortality data in
the years to come. Since the ICD-11 may allow giving more details to the
conditions by combining with characteristics, it will now be possible to
provide more data related to the deaths when they are available, such as
severity, etiology.

The ICD-11 was presented and adopted by the 72\textsuperscript{nd} World
Health Assembly in May 2019 and the implementation of this new
classification is ongoing worldwide (41). Although ICD-11 will come into
effect in 1\textsuperscript{st} January 2022, some countries such as the
US may take longer to fully adopt ICD-11.

\emph{The Montpellier WHO Collaborating Centre for Classification
Scientific Support}

In June 2018, the \textbf{WHO Collaborating Center (WHO CC) for the
Scientific Classification Support (CSS)} was established at the
University Hospital of Montpellier, headed by LKT and PD (42). This
designation is the result of recognition by WHO of all the efforts
of\emph{the ALLERGY in ICD-11 initiative} and is intended to provide
academic, research and scientific support to WHO in the implementation,
refinement and maintenance of the WHO-FIC in the areas of our expertise.
Furthermore, LKT has been co-opted by WHO into the small \textbf{Medical
and Scientific Advisory Board} recently created to support the
maintenance of ICD-11 and other WHO FIC classifications (43).

The WHO-FIC (Family of International Classifications) Network CC also
assists WHO in the revision and development of ICD and other WHO
reference classifications (38). The Montpellier WHO CC for A/H is
involved in national and international initiatives in order to ensure
quality implementation of ICD-11 and other WHO international
classifications, taking A/H as a model. These include education modules
to support quality of classification and coding under the new framework
and collaboration work with other institutions. In this context, we here
present the outcomes of a engagement process involving the allergy
community in which the \emph{principal terms} and definitions of the
pioneer \emph{Allergic and hypersensitivity conditions} section of the
ICD-11 could be scrutinised. This step is critical for the
implementation process by strengthening awareness and preparing the
allergy community for ICD-11.

ONE VOICE FOR THE ALLERGY COMMUNITY IN THE IMPLEMENTATION OF THE ICD-11

To reach out the allergy community worldwide, we developed a web-based
survey in English, which was launched via Internet and circulated for 7
weeks (August to October 2019). The survey was anonymous and voluntary.
An online questionnaire was constructed using
GoogleDocs\textsuperscript{R}, enabling responses to be recorded in a
unique database. We sent out an introduction letter containing a link to
the questionnaire unique to each participating member. We received help
from a number of relevant international and national academies in
distributing the survey among their members. The link directed
respondents to a page explaining the purpose of the survey. A reminder
was sent out after 4 weeks. The survey has been disseminated by e-mail
and by social media.

Of the 35 questions, 6 related to the utility of ICD and 15 to the
content of the Allergic and hypersensitivity conditions section,
specifically the nomenclature and definitions of the main conditions in
each of the 6 principal domains: i) allergic or hypersensitivity
disorders involving the respiratory tract; ii) allergic or
hypersensitivity disorders involving the eye; iii) allergic or
hypersensitivity disorders involving the skin and mucous membranes; iv)
allergic or hypersensitivity disorders involving the digestive tract; v)
anaphylaxis; and vi) complex allergy disorders (drug, food and
Hymenoptera hypersensitivity) (Annex 1).

The following numeric scoring system was used: 0 (not at all accurate),
1 (low accuracy, but possible to use), 2 (acceptable accuracy), 3 (good
accuracy) and 4 (extremely accurate). We originally planned to analyse
the responses for each of the 6 domains but realised on receipt of the
responses that it would be necessary to amalgamate some domains in order
to facilitate the communication of the results.

\emph{Engaging the allergy community: what the ICD-11 can bring us?}

Data are presented here for the 406 respondents (Table 1) from 74
countries who completed the survey (Figure 1). The countries were
aggregated according to the six WHO global regions -- AFRO (primarily
sub-Saharan Africa), PAHO (the Americas), EMRO (Eastern
Mediterranean/North Africa), EURO (Europe), SEARO (Southeast Asia), and
WPRO (Western Pacific) -- and across the global sample. Table 1 provides
a list of participating countries, number of participants from each
allergy society, mean age of respondents, sex ratio, specialty,
professional experience, percent of professionals who spend more than 20
hours/week looking after patients suffering from A/H diseases, working
setting, information relating to coding practice in day-to-day clinical
work and a rating of the appropriateness of the classification system in
use. As shown in Figure 1 and Table 1, all WHO global regions were
represented in the survey. Response rates were lowest for AFRO (1.7\%)
and highest for EURO (46.5\%).

Allergists with long-time professional experience working in private
and/or public settings were the principal respondents to the survey and
97\% of these reported seeing allergic patients regularly (Table 1);
71\% of this group reported having more than 10 years of professional
experience in A/H and nearly two thirds (64.5\%) spent more than 20
hours per week seeing A/H patients.

As shown in Table 1, 59\% of the respondents use ICD-10 or national
adaptations thereof in their daily clinical work; 11.4\%, mainly from
the AFRO region, use ICD-9 or its national adaptations. A high
proportion of respondents (72.2\%) from the EMRO region do not use any
classification/ coding system. 56.9\% of the respondents mentioned that
they were personally responsible for coding diseases/interventions in
their practice and 25.1\% reported that a staff member of their practice
or institution perform this task.

From overall responses, the main utility of a classification and coding
system was judged to be the ``basis for generating national health
statistics'', followed by ``to support communication between
clinicians''. The responses differed according to the world regions
(Figure 2). For instance, most of participants from the SEARO region use
the classification for ``communication with the payers'' whereas ERMRO
representatives use it for ``communication between clinicians and
patients''.

Although ICD-10 was shown to be the classification system most used
worldwide, 69.5\% of users did not consider it appropriate for clinical
practice. The participants highlighted the need for inclusion of missing
allergic diseases (75.3\%) and the presence of diseases with overlapping
classification (\emph{e.g.,} Asthma induced by Aspirin) (64\%). In
response to these needs, the respondents were aware that ICD-11 will
allow more accurate representation of A/H (77.1\%), will support
harmonization of terminology and definitions in the field of allergy
(56.9\%) and will be able to support correct diagnosis and management
(49.5\%) (Table 2).

\emph{Harmonizing allergy and hypersensitivity nomenclature and
definitions}

As demonstrated in Figure 2, we observed a similar pattern of responses
relating to the accuracy evaluation of the new ICD-11 \emph{Allergic and
hypersensitivity conditions} classification. All of the sections had the
score 3 (good accuracy) selected by the majority of respondents.

The nomenclature and definitions of ``allergic rhinitis'', ``allergic
asthma'' and ``anaphylaxis'' received the best scores (3 and/or 4). On
the other hand, in contrast with other sections, ``Dermatitis or
eczema'', ``non-allergic asthma'' and the ``Allergic or hypersensitivity
reactions to arthropods'' subsection presented higher proportion of
scores 1 and 2 (Figure 2). We received 49 responses to open questions
with suggestions covering missing conditions (\emph{e.g} ., primary
immunodeficiency), inclusion of underlying mechanism or causes and
requests for simplification of the section.

LESSONS FROM THE ENGAGEMENT PROCESS

The implementation phase of ICD-11 is currently ongoing. The main
framework of the new classification was presented to the WHA in May 2019
(41). Refinements of ICD-11 are led by the ICD-11 governance team and
supported by the WHO-FIC networks comprising the reference groups and
advisory committees of WHO. The Montpellier WHO CC CSS plays a special
role in supporting the WHO through its academic and research projects.
The data provided by these initiatives will be essential for fine-tuning
improvements in the \emph{Allergic and hypersensitivity
conditions}section of ICD. In fact, this section has been serving as a
model for the refinement process, since it is the first time that many
of these conditions have been represented together in a single location
by means of the polyhierarchical design of ICD-11. Considering the fact
that every change to the existing framework can have consequences not
only for the allergy specialty but also for other specialties, all
modifications have to be carefully and deeply considered and agreed with
the concerned parts. Input mechanisms required demonstrated scientific
evidence and consensus across all ICD stakeholders.

The outcomes of this engagement process have provided a snapshot view of
how the international classifications are currently being used and of
how we will be able to work together with WHO to assist adoption of the
new A/H classification. For instance, those countries in which no
classification system is used are being targeted for early adoption of
ICD-11, and other countries using ICD-9 (or national adaptations) will
be able to transfer directly to ICD-11.

In this survey, we decided to include only the main terms and
definitions in the new A/H classification in order to simplify the task
for our respondents and in the hope of thereby obtaining a higher
response rate. For this reason many of the 49 responses to the open
question of the survey were related to entities not mentioned in the
proposed survey. However, all the comments have been taken into account,
considering that ICD-11 is not intended to be a specialty classification
but a system for use by a broad range of end-users.

Appropriate usage of codes for recording disorders is a key issue to
prevent misclassification. The results of the current survey underline
the need for increasing awareness of ICD-11 and its coding procedures as
well as for educational programs to support ICD-11 end-users. These are
two further goals of the Montpellier WHO CC.

Over recent decades the allergy community has been concerned to improve
terminology and definitions in the field of allergy, as evidenced in
many documents which have been published to date (44-74). The
harmonization of A/H terminology and definitions is critical for our
community in today's globalized world with its international multicentre
clinical trials and with the development of ``personalized medicine''.
All the main published international consensuses and guidelines in the
field of A/H have been considered in the drafting of the
ICD-11\emph{Allergic and hypersensitivity conditions} classification in
the ICD-11 chapter. The ICD-11 is recognized by the allergy community as
the main official means to reach global harmonization in nomenclature
and definitions to support the allergy community in the years to come.
The allergy community recognizes the ICD-11 as a clinical tool and
classification, in strong contrast to ICD-10 that designed for
statistics only. This is an important finding of the survey which you
should also highlight. Meanwhile, immunological disorders have been
updated under the same chapter, including for example immunodeficiencies
and rare diseases.

Many quality measures, such as those from US HealthGrades and the Agency
for Healthcare Research and Quality, rely on the WHO ICD codes.
Improving the specification of conditions will help clarify the
connection between a provider's performance and the patient's condition.
Accurate and updated diagnostic and procedure codes will improve data on
the outcomes, efficacy, and costs of new medical technology and will
facilitate fair reimbursement policies. It will help payers and
providers to identify patients in need of disease management more easily
and will more effectively tailor disease management programs (27).

By allowing all the relevant diagnostic terms for allergic and
hypersensitivity conditions to be included in ICD-11, WHO has recognized
their importance not only to clinicians but also to public health and
those involved in studying and managing it, including epidemiologists,
statisticians, health care planners and other stakeholders. Importantly,
the new classification will enable the collection of more accurate
epidemiological data to support quality management of patients with
allergies and to better facilitate health care planning and
decision-making, including public health measures to prevent and reduce
the mortality and morbidity attributable to A/H. The improved
ontological structure of ICD-11 and standardized terminology and
definitions throughout the ICD-11 will also facilitate international
comparisons of quality care and the sharing of best practice globally.

An important limitation of the survey is the differential response rate
by regional area. We consider, however, that it is the quality of
responses received rather than their quantity or their geographical
representativeness that is most important. Although this did not affect
our overall data analysis, it may highlight the need for allergy
specialty development in the areas where the number of responders was
low. Despite the specific response rate, the survey represented a unique
opportunity to give voice to colleagues from 74 countries. In some
countries, notably China, the most populous nation in the world, we
received fewer responses than might have been expected. We hypothesise
that recipients may not have been able to access the survey due to
national regulations prohibiting Google\textsuperscript{®} accounts.
Other factors which may have influenced the response rate include the
high number of questions for busy doctors and health professionals to
answer, difficulty in accessing the online questionnaire and
difficulties with the English language. Also it was not possible to have
the initial sample size parameter since the survey has been disseminated
by e-mail, social media and through national or regional allergy
academies.

We believe that, in addition to helping during the implementation phase
of the new ICD-11 ``Allergic and hypersensitivity conditions''
classification, all the comments provided will help to improve the A/H
classification and to increase awareness by different disciplines of
what actions are needed to ensure more accurate epidemiological data and
better clinical management of patients with allergic and
hypersensitivity disorders. The efforts presented in this manuscript are
aligned to additional ongoing national and international actions in
order to ensure quality of allergy and hypersensitivity conditions data
in the forthcoming years.

ABREVIATIONS

A/H: allergic and hypersensitivity conditions

AAAAI: American Academy of Allergy Asthma and Immunology

ACAAI: American College of Allergy Asthma and Immunology

AFRO: primarily sub-Saharan Africa

APAAACI: Asia Pacific Association of Allergy, Asthma and Clinical
Immunology

EAACI: European Academy of Allergy and Clinical Immunology

EMRO: Eastern Mediterranean/North Africa

EURO: Europe

ICD: International Classification of Diseases

MMS: Mortality and morbidity statistics

PAHO: the Americas

SEARO: Southeast Asia

SLAAI: Latin American Society of Allergy, Asthma and Immunology

WAO: World Allergy Organization

WHA: World Heal Assembly

WHO: World Health Organization

WHO-FIC: World Health Organization - Family of International
Classifications

WHO CC: World Health Organization Collaborating Centre

WPRO: Western Pacific

References

\begin{enumerate}
\tightlist
\item
  Cornet R, Chute CG. Health Concept and Knowledge Management:
  twenty-five Year of Evolution. Yearb Med Inform. 2016 Aug 2;Suppl
  1:S32-41.
\item
  Demoly P, Tanno LK, Akdis CA, Lau S, Calderon MA, Santos AF, et al.
  Global classification and coding of hypersensitivity diseases -- An
  EAACI -- WAO survey, strategic paper and review. Allergy 2014; 69:
  559--570.
\item
  World Heath Organization ICD-11 website (cited, available:
  https://www.who.int/classifications/icd/en/ accessed February 2020).
\item
  Knibbs GH. The International classification of disease and causes of
  death and its revision. Med J Aust 1929;1:2-12.
\item
  Moriyama IM, Loy RM, Robb-Smith AHT. History of the statistical
  classification of diseases and causes of death. Rosenberg HM, Hoyert
  DL, eds. Hyattsville, MD: National Center for Health Statistics 2011.
\item
  National Academy on an Aging Society. Chronic Conditions: A challenge
  for the 21st Century. 2000.
\item
  Centers for Disease Control. ``CDC Fast Facts A-Z,'' Vital Health
  Statistics. 2003 {[}cited 28 Oct 2011{]}.
  http://www.cdc.gov/nchs/fastats/allergies.htm,
  http://www.aafa.org/display.cfm?id=9\&sub=30 (accessed 5 Sept 2011)
\item
  Center of Disease Control and Prevention (CDC) website. (cited,
  available: https://www.cdc.gov/nchs/fastats/health-expenditures.htm
  accessed February 2020)
\item
  Tanno LK, Calderon MA, Goldberg BJ, Akdis CA, Papadopoulos NG, Demoly
  P. Categorization of Allergic Disorders in the New World Health
  Organization International Classification of Diseases. Clin Transl
  Allergy 2014; 4: 42.
\item
  Tanno LK, Ganem F, Demoly P, Toscano CM, Bierrenbach AL.
  Undernotification of anaphylaxis deaths in Brazil due to difficult
  coding under the ICD-10. Allergy 2012; 67: 783--789.
\item
  Papadopoulos NG, Agache I, Bavbek S, Bilo BM, Braido F, Cardona V et
  al. Research needs in allergy: an EAACI position paper, in
  collaboration with EFA. Clin Transl Allergy 2012;2:21.
\item
  Pawankar R, Canonica GW, ST Holgate ST, Lockey RF, Blaiss M. The WAO
  White Book on Allergy (Update. 2013)
\item
  Tanno LK, Calderon MA, Smith HE, Sanchez-Borges M, Sheikh A, Demoly P;
  Joint Allergy Academies. Dissemination of definitions and concepts of
  allergic and hypersensitivity conditions. World Allergy Organ J. 2016;
  9: 24.
\item
  World Health Organization, ICD-11 Beta Draft website. (cited,
  available: http://apps.who.int/classifications/icd11/browse/l-m/en
  January 2020).
\item
  Tanno LK, Casale T, Papadopoulos NG, Sanchez-Borges M, Thiens F,
  Pawankar R, Calderon MA, Gómez M, Sisul JC, Ansotegui IJ, Sublett J,
  Demoly P. A call to arms of specialty societies to review the WHO
  International Classification of Diseases, Eleventh Revision terms
  appropriate for the diseases they manage: The example of the Joint
  Allergy Academies. Allergy Asthma Proc. 2017 Jul 1;38(4):54-55.
\item
  Tanno LK, Calderon MA, Goldberg BJ, Gayraud J, Bircher AJ, Casale T et
  al. Constructing a classification of hypersensitivity/allergic
  diseases for ICD-11 by sourcing the allergist community. Allergy 2015;
  70: 609-15.
\item
  Tanno LK, Calderon MA, Demoly P; on behalf the Joint Allergy
  Academies. New Allergic and Hypersensitivity Conditions Section in the
  International Classification of Diseases-11. Allergy Asthma Immunol
  Res 2016; 8: 383-8.
\item
  Tanno LK, Simons FE, Annesi-Maesano I, Calderon MA, Aymé S, Demoly P;
  Joint Allergy Academies. Fatal anaphylaxis registries data support
  changes in the who anaphylaxis mortality coding rules. Orphanet J Rare
  Dis 2017; 12: 8.
\item
  Tanno LK, Bierrenbach AL, Simons FER, Cardona V, Thong BY, Molinari N,
  Calderon MA, Worm M, Chang YS, Papadopoulos NG, Casale T, Demoly P; on
  behalf the Joint Allergy Academies. Critical view of anaphylaxis
  epidemiology: open questions and new perspectives. Allergy Asthma Clin
  Immunol 2018; 14: 12.
\item
  Tanno LK, Calderon M, Papadopoulos NG, Demoly P. Mapping
  hypersensitivity/allergic diseases in the International Classification
  of Diseases (ICD)-11: cross-linking terms and unmet needs. Clin Transl
  Allergy 2015; 5: 20.
\item
  Tanno LK, Calderon MA, Demoly P; on behalf the Joint Allergy
  Academies. Making allergic and hypersensitivity conditions visible in
  the International Classification of Diseases-11. Asian Pac Allergy
  2015; 5: 193-6.
\item
  Tanno LK, Calderon MA, Demoly P; on behalf the Joint Allergy
  Academies. Optimization and simplification of the allergic and
  hypersensitivity conditions classification for the ICD-11. Allergy
  2016; 71: 671-6.
\item
  Tanno LK, Calderon MA, Papadopoulos NG, Sanchez-Borges M, Rosenwasser
  LJ, Bousquet J, et al. Revisiting Desensitization and Allergen
  Immunotherapy Concepts for the International Classification of
  Diseases (ICD)-11. J Allergy Clin Immunol Pract 2016; 4: 643-9.
\item
  Tanno LK, Calderon MA, Li J, Casale T, Demoly P. Updating
  Allergy/Hypersensitivity diagnostic procedures in the WHO ICD-11
  revision. J Allergy Clin Immunol Pract 2016; 4: 650-7.
\item
  Tanno LK, Calderon MA, Papadopoulos NG, Sanchez-Borges M, Moon HB,
  Sisul JC, Jares EJ, Sublett JL, Casale T, Demoly P; Joint Allergy
  Academies. Surveying the new allergic and hypersensitivity conditions
  chapter of the International classification of diseases (ICD)-11.
  Allergy 2016; 71: 1235-40.
\item
  Tanno LK, Calderon M, Demoly P; Joint Allergy Academies. Supporting
  the validation of the new allergic and hypersensitivity conditions
  section of the World Health Organization International Classification
  of Diseases-11. Asia Pac Allergy 2016; 6: 149-56.
\item
  Tanno LK, Calderon M, Sublett JL, Casale T, Demoly P; Joint Allergy
  Academies. Smoothing the transition from International Classification
  of Diseases, Tenth Revision, Clinical Modification to International
  Classification of Diseases, Eleventh Revision. J Allergy Clin Immunol
  Pract 2016; 4: 1265-7.
\item
  Tanno LK, Bierrenbach AL, Calderon MA, Sheikh A, Simons FE, Demoly P;
  Joint Allergy Academies. Decreasing the undernotification of
  anaphylaxis deaths in Brazil through the International Classification
  of Diseases (ICD)-11 revision. Allergy 2017; 72: 120-5.
\item
  Tanno LK, I Ansotegui, P Demoly. Globalization and anaphylaxis. Curr
  Opin Allergy Clin Immunol 2018\emph{;} in press - doi:
  10.1097/ACI.0000000000000467
\item
  Tanno LK, Molinari N, Bruel S, Bourrain JL, Calderon M, Aubas P,
  Demoly P; Joint Allergy Academies. Field-testing the New Anaphylaxis'
  Classification for the WHO International Classification of Diseases
  (ICD)-11 Revision. Allergy. 2017 May;72(5):820-826. doi:
  10.1111/all.13093.
\item
  Tanno LK, Sublett JL, Meadows JA, Calderon M, Gross GN, Casale T,
  Demoly P; Joint Allergy Academies. Perspectives of the International
  Classification of Diseases (ICD)-11 in Allergy Clinical Practice in
  the United States of America. Ann Allergy Asthma Immunol. 2017
  Feb;118(2):127-132.
\item
  Tanno LK, Chalmers RJ, Calderon MA, Aymé S, Demoly P; on behalf the
  Joint Allergy Academies. Reaching multidisciplinary consensus on
  classification of anaphylaxis for the eleventh revision of the World
  Health Organization's (WHO) International Classification of Diseases
  (ICD-11).Orphanet J Rare Dis. 2017 Mar 16;12(1):53.
\item
  Tanno LK, Calderon MA, Linzer JFSr, Chalmers RJG, Demoly P, on behalf
  of the Joint Allergy Academies. Collaboration between specialties for
  respiratory allergies in the international classification of diseases
  (ICD)-11. Respiratory Research 2017, Feb 10;18(1):34.
\item
  Tanno LK, Haahtela T, Calderon MA, Cruz A, Demoly P; Joint Allergy
  Academies. Implementation gaps for asthma prevention and control.
  Respir Med. 2017 Sep;130:13-19.
\item
  Tanno LK, Torres MJ, Castells M, Demoly P; Joint Allergy Academies.
  What can we learn in drug allergy management from World Health
  Organization's International classifications? Allergy. 2018
  May;73(5):987-992.
\item
  Tanno LK, Demoly P. Lessons of Drug Allergy Management Through the
  World Health Organization's International Classification of Diseases
  (ICD)-11. Curr Treatment Opin in Allergy, 2018 March 5 (1):52-59.
\item
  Tanno LK, Demoly P, on behalf of the Joint Allergy Academies. How can
  the World Health Organization's International Classification of
  Diseases (ICD)-11 change the clinical management of anaphylaxis?
  Expert Rev Clin Immunol. 2018 Sep 11:1-4. doi:
  10.1080/1744666X.2018.1520094.
\item
  Tanno LK, Demoly P; Joint Allergy Academies. Are outcome measures in
  allergic diseases relevant for the WHO's International Classification
  of Diseases in allergology? Curr Opin Allergy Clin Immunol. 2019
  Jun;19(3):198-203.
\item
  Tanno LK, Chalmers R, Bierrenbach AL, Simons FER, Molinari N,
  Annesi-Maesano et al. on behalf Joint Allergy Academies. Changing the
  history of anaphylaxis mortality statistics througth the World Health
  Organization's International Classification of Diseases (ICD)-11. J
  Allergy Clin Immunol. 2019 Sep;144(3):627-633.
\item
  Demoly P, Tanno LK. Le modèle de l'anaphylaxie : une nouvelle version
  de la Classification Internationale des Maladies de l'Organisation
  Mondiale de la Santé pour 2019. \emph{Bulletin de l'Académie nationale
  de médecine 2020, in press}
\item
  The Lancet. ICD-11. Lancet. 2019 Jun 8;393(10188):2275.
\item
  World Health Organization, Collaborating Centres list website. (cited,
  available:
  http://apps.who.int/whocc/Detail.aspx?cc\_ref=FRA-133\&designation\_date1=1/6/2018\&designation\_date2=18/7/2018\&
  December 2019)
\item
  World Health Organization, MSAC website. (cited, available:
  https://www.who.int/classifications/icd/revision/en/ December 2019)
\item
  Johansson SG, Bieber T, Dahl R, et al. Revised nomenclature for
  allergy for global use: Report of the Nomenclature Review Committee of
  the World Allergy Organization, October 2003. J Allergy Clin Imunnol
  2004; 113: 832-6.
\item
  The European Academy of Allergy and Clinical Immunology (EAACI). A
  European Declaration on Allergen Immunotherapy. Available at
  http://www.eaaci.org/resources/immunotherapy- declaration.html
\item
  Demoly P, Adkinson NF, Brockow K, Castells M, Chiriac AM, Greenberger
  PA, Khan DA, Lang DM, Park H-S, Pichler W, Sanchez-Borges M, Shiohara
  T, Thong BY-H. International Consensus on drug allergy. Allergy 2014;
  69: 420--437.
\item
  Sampson HA, Munoz-Furlong A, Campbell RL, Adkinson NF Jr, Bock SA,
  Branum A et al. Second symposium on the definition and management of
  anaphylaxis: summary report -- Second National Institute of Allergy
  and Infectious Disease/Food Allergy and Anaphylaxis Network Symposium.
  J Allergy Clin Immunol 2006;117:391-- 397.
\item
  Scadding G, Hellings P, Alobid I, Bachert C, et al., Diagnostic tools
  in Rhinology EAACI position paper. Clinical and Translational Allergy
  201110;1(1):2.
\item
  Fokkens W, Lund V, Mullol J; European Position Paper on Rhinosinusitis
  and Nasal Polyps. Rhinol Suppl 2007;(20):1-136.
\item
  Bousquet J, Schu~\selectlanguage{english}\selectlanguage{english}nemann HJ, Zuberbier T, Bachert C, Baena-Cagnani CE,
  Bousquet PJ, et al. In collaboration with the WHO Collaborating Center
  of Asthma and Rhinitis (Montpellier). Development and implementation
  of guide- lines in allergic rhinitis -- an ARIA-GA2LEN paper. Allergy
  2010; 65: 1212--1221.
\item
  L. B. Bacharier, A. Boner, K.-H. Carlsen, P. A. Eigenmann, T.
  Frischer, M. Gc\selectlanguage{english}tz et al. Diagnosis and treatment of asthma in
  childhood: a PRACTALL consensus report. Allergy 2008: 63: 5--34.
\item
  Asthma. Quick asthma facts \& The Faces of asthma {[}Internet{]}.
  Geneva: World Health Organization; 2010. Available from:
  http://www.who.int/respiratory/asthma/en/.
\item
  Matthew Masoli, Denise Fabian, Shaun Holt, Richard Beasley for the
  Global Initiative for Asthma (GINA) Program. The global burden of
  asthma: executive summary of the GINA. Dissemination Committee Report.
  Allergy 2004: 59: 469--478.
\item
  Bateman ED, Bousquet J, Keech ML, Busse WW, Clark TJ, Pedersen SE.The
  correlation between asthma control and health status: the GOAL study.
  Eur Respir J 2007; 29: 56-62.
\item
  Papadopoulos NG, Arakawa H, Carlsen K-H, Custovic A, Gern J, Lemanske
  R, et al.. International consensus on (icon) pediatric asthma. Allergy
  2012; 67: 976--997.
\item
  Burks AW, Tang M, Sicherer S, Muraro A,  Eigenmann PA, Ebisawa M,
  Fiocchi A, Chiang W, Beyer K, Wood R, Hourihane J, Jones SM,  Lack G,
  Sampson HA. International consensus on (ICON) Food Allergy. J Allergy
  Clin Immunol 2012; 129: 906-920.
\item
  Simons FE, Ardusso LR, Bil\selectlanguage{ngerman}ò MB, Cardona V, Ebisawa M, El-Gamal YM, et
  al. International consensus on (ICON) Anaphylaxis. World Allergy Organ
  J 2014 30;7: 9.
\item
  Moscato G, Pala G, Cullinan P, Folletti I, Gerth van Wijk R, Pignatti
  P et al. EAACI Position Paper on assessment of cough in the workplace.
  Allergy 2014;69: 292-304.
\item
  Leonardi A, Bogacka E, Fauquert J-L, Kowalski ML, Groblewska A,
  Jedrzejczak-Czechowicz M, et al. Ocular allergy: recognizing and
  diagnosing hypersensitivity disorders of the ocular surface. Allergy
  2012; 67: 1327--1337.
\item
  La Rosa M, Lionetti E, Reibaldi M, Russo A, Longo A, Leonardi S, et
  al. Allergic conjunctivitis: a comprehensive review of the literature.
  Italian J Pediatrics 2013, 39:18.
\item
  Bonini S, Coassin M, Aronni S, Lambiase A. Vernal
  keratoconjunctivitis. Eye 2004; 18: 345--351.
\item
  Akdis CA, Akdis M, Bieber T, Bindslev-Jensen C, Boguniewicz M,
  Eigenmann PA, et al. Diagnosis and treatment of atopic dermatitis in
  children and adults: European Academy of Allergology and Clinical
  Immunology/American Academy of Allergy, Asthma and Immunology/PRACTALL
  Consensus Report. Allergy 2006: 61: 969--987.
\item
  Bonitsis NG, Tatsioni A, Bassioukas K, Ioannidis JP.Allergens
  responsible for allergic contact dermatitis among children: a
  systematic review and meta-analysis. Contact Dermatitis 2011;64:
  245-57.
\item
  Tan CH, Rasool S, Johnston GA.Contact dermatitis: allergic and
  irritant. Clin Dermatol 2014;32:116-24.
\item
  Cicardi M, Bork K, Caballero T, Craig T, Li HH, Longhurst H,et al.
  Evidence-based recommendations for the therapeutic management of
  angioedema owing to hereditary C1 inhibitor deficiency: consensus
  report of an International Working Group. Allergy. 2012;67: 147-57.
\item
  Craig T, Aygo\selectlanguage{english}ren Pu\selectlanguage{english}rsu\selectlanguage{english}n E, Bork K, Bowen T, Boysen H, Farkas H, et al.
  WAO Guideline for the Management of Hereditary Angioedema. WAO J 2012;
  5: 182--199.
\item
  Soares-Weiser K, Panesar SS, Rader T, Takwoingi Y, Werfel T, Muraro A,
  et al. The diagnosis of food allergy: protocol for a systematic
  review. Clin Transl Allergy 2013, 3:18.
\item
  Bircher A, Scherer K. Delayed cutaneous manifestations of drug
  hypersensitivity.Med Clin North Am. 2010;94:711-25.
\item
  Pirmohamed M, Friedmann PS, Molokhia M, Loke YK, Smith C, Phillips E,
  La Grenade L, Carleton B, Papaluca-Amati M, Demoly P, Shear
  NH.Phenotype standardization for immune-mediated drug-induced skin
  injury. Clin Pharmacol Ther 2011;89:896-901.
\item
  Roujeau JC. Clinical heterogeneity of drug hypersensitivity.
  Toxicology 2005\emph{;} 15;209:123-129.
\item
  Bil\selectlanguage{ngerman}ó BM, Rueff F, Mosbech H, Bonifazi F, Oude-Elberink JN; EAACI
  Interest Group on Insect Venom Hypersensitivity.Diagnosis of
  Hymenoptera venom allergy.Allergy. 2005;60:1339-1349.
\item
  Bonifazi F, Jutel M, Biló BM, Birnbaum J, Muller U; EAACI Interest
  Group on Insect Venom Hypersensitivity.Prevention and treatment of
  hymenoptera venom allergy: guidelines for clinical practice. Allergy
  2005;60: 1459-1470.
\item
  Time to revisit the definition and clinical criteria for anaphylaxis?
  Turner PJ, Worm M, Ansotegui IJ, El-Gamal Y, Rivas MF, Fineman S,
  Geller M, Gonzalez-Estrada A, Greenberger PA, Tanno LK, Borges MS,
  Senna G, Sheikh A, Thong BY, Ebisawa M, Cardona V; WAO Anaphylaxis
  Committee. World Allergy Organ J. 2019 Oct 31;12(10):100066.
\item
  Zuberbier T, Aberer W, Asero R, Abdul Latiff AH, Baker D,
  Ballmer-Weber B, et al. The EAACI/GA²LEN/EDF/WAO guideline for the
  definition, classification, diagnosis and management of urticaria.
  Allergy. 2018 Jul;73(7):1393-1414.
\end{enumerate}

FUNDING:

Pascal Demoly and Luciana Kase Tanno received an unrestricted Novartis
and MEDA/Mylan Pharma grants through CHUM administration. LKT received a
research AllerGOS grant.

CONFLICT OF INTERESTS:

The authors declare that they do not have conflict of interests related
to the contents of this article.

CONTRIBUTIONS:

The first and last authors contributed to the construction of the
document (designed the study, including the questionnaire, analysed and
interpreted the data, and wrote the manuscript). All the authors
critically revised and approved the final version of the manuscript and
agree to be accountable for all the aspects of the work.

AKNOWLEDGEMENTS:

We are grateful to all the representatives of the ICD-11 revision with
whom we have been carrying on fruitful discussions, helping us to tune
the here presented classification: Robert Jakob, Linda Best, Nenad
Kostanjsek, Linda Moskal, Robert J G Chalmers, Jeffrey Linzer, Linda
Edwards, Ségolène Ayme, Bertrand Bellet, Rodney Franklin, Matthew
Helbert, August Colenbrander, Satoshi Kashii, Paulo E. C. Dantas,
Christine Graham, Ashley Behrens, Julie Rust, Megan Cumerlato, Tsutomu
Suzuki, Mitsuko Kondo, Hajime Takizawa, Nobuoki Kohno, Soichiro Miura,
Nan Tajima and Toshio Ogawa.

We would like to thank very much the national and international
academies, and colleagues who supported the dissemination of the online
survey. We are grateful for the participants for their responses.

LIST OF TABLES

Table 1: Responder to the international survey, response rates,
demographic characteristics, and classification in use

Table 2: Responses to open ended questions from a web international
survey fielded in 2019: what is expected by a classification system and
what the ICD-11 is able to bring

\textbf{LIST OF FIGURES}

Figure 1: Representation of the participants to the international survey
per world region

Figure 2: The main purpose for a classification system according to the
allergy community and analysis per region

Figure 3: Outcomes of the engaging opinion process: scoring the accuracy
of the ICD-11 \emph{Allergic and hypersensitivity conditions} section

Annex 1: Questionnaire ``GLOBAL IMPLEMENTATION OF THE WORLD HEALTH
ORGANIZATION'S INTERNATIONAL CLASSIFICATION OF DISEASES (ICD)-11: THE
ALLERGIC AND HYPERSENSITIVITY CONDITIONS MODEL''.

\textbf{Hosted file}

\verb`image1.emf`  available at \url{https://authorea.com/users/323350/articles/452072-global-implementation-of-the-world-health-organization-s-international-classification-of-diseases-icd-11-the-allergic-and-hypersensitivity-conditions-model}

Figure 2: Representation of the participants to the international survey
per world region

\textbf{Hosted file}

\verb`image2.emf`  available at \url{https://authorea.com/users/323350/articles/452072-global-implementation-of-the-world-health-organization-s-international-classification-of-diseases-icd-11-the-allergic-and-hypersensitivity-conditions-model}

Figure 2: The main purpose for a classification system according to the
allergy community and analysis per region

\textbf{Hosted file}

\verb`image3.emf`  available at \url{https://authorea.com/users/323350/articles/452072-global-implementation-of-the-world-health-organization-s-international-classification-of-diseases-icd-11-the-allergic-and-hypersensitivity-conditions-model}

Figure 3: Outcomes of the engaging opinion process: scoring the accuracy
of the ICD-11 \emph{Allergic and hypersensitivity conditions} section

Table 1: Responders to the international survey, response rates,
demographic characteristics, and classification in use\selectlanguage{english}
\begin{longtable}[]{@{}llllllllllll@{}}
\toprule
\begin{minipage}[b]{0.06\columnwidth}\raggedright\strut
\textbf{WHO Global Region}\strut
\end{minipage} & \begin{minipage}[b]{0.06\columnwidth}\raggedright\strut
\textbf{Country (N responses)}\strut
\end{minipage} & \begin{minipage}[b]{0.06\columnwidth}\raggedright\strut
\textbf{Total N\textsuperscript{O} responses}\strut
\end{minipage} & \begin{minipage}[b]{0.06\columnwidth}\raggedright\strut
\textbf{Mean age (years)}\strut
\end{minipage} & \begin{minipage}[b]{0.06\columnwidth}\raggedright\strut
\textbf{Ratio women/men}\strut
\end{minipage} & \begin{minipage}[b]{0.06\columnwidth}\raggedright\strut
\textbf{Specialty (\%)}\strut
\end{minipage} & \begin{minipage}[b]{0.06\columnwidth}\raggedright\strut
\textbf{More than 20 years of professional experience (\%)}\strut
\end{minipage} & \begin{minipage}[b]{0.06\columnwidth}\raggedright\strut
\textbf{\% spending more than 20 hours/ week with allergic
diseases}\strut
\end{minipage} & \begin{minipage}[b]{0.06\columnwidth}\raggedright\strut
\textbf{Work setting (\%)}\strut
\end{minipage} & \begin{minipage}[b]{0.06\columnwidth}\raggedright\strut
\textbf{In your practice, who codes diseases/ interventions?}\strut
\end{minipage} & \begin{minipage}[b]{0.06\columnwidth}\raggedright\strut
\textbf{Classification/ coding tool used in the day-to-day clinical work
(\%)}\strut
\end{minipage} & \begin{minipage}[b]{0.06\columnwidth}\raggedright\strut
\textbf{Do you think the classification system you are using is
appropriate for your practice? (\%)}\strut
\end{minipage}\tabularnewline
\midrule
\endhead
\begin{minipage}[t]{0.08\columnwidth}\raggedright\strut
\textbf{AFRO}\strut
\end{minipage} & \begin{minipage}[t]{0.08\columnwidth}\raggedright\strut
Algeria (2) Kenya (1) Nigeria (1) South Africa (2) Zimbabwe (1)\strut
\end{minipage} & \begin{minipage}[t]{0.08\columnwidth}\raggedright\strut
7\strut
\end{minipage} & \begin{minipage}[t]{0.08\columnwidth}\raggedright\strut
49.5\strut
\end{minipage} & \begin{minipage}[t]{0.08\columnwidth}\raggedright\strut
0.16\strut
\end{minipage} & \begin{minipage}[t]{0.08\columnwidth}\raggedright\strut
Allergist (29) Clinical Immunologist (14.2) Pulmonologist (14.2)
Paediatrician (14.2) Researcher (14.2) Other (14.2)\strut
\end{minipage} & \begin{minipage}[t]{0.08\columnwidth}\raggedright\strut
57.1\strut
\end{minipage} & \begin{minipage}[t]{0.08\columnwidth}\raggedright\strut
57.1\strut
\end{minipage} & \begin{minipage}[t]{0.08\columnwidth}\raggedright\strut
Private (28.6) Public (42.8) Both (28.6)\strut
\end{minipage} & \begin{minipage}[t]{0.08\columnwidth}\raggedright\strut
Yourself (43.0) A staff member/ institution (14.0) Nobody (43.0) I don't
know (0.0)\strut
\end{minipage} & \begin{minipage}[t]{0.08\columnwidth}\raggedright\strut
ICD-10 (+ adaptation) (57.1) ICD-9 (+ adaptation) (14.3) SNOMED-CT (0.0)
Read Codes (14.3) None (14.3) Other (0.0)\strut
\end{minipage} & \begin{minipage}[t]{0.08\columnwidth}\raggedright\strut
Yes (42.8) No (57.2)\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.08\columnwidth}\raggedright\strut
\textbf{PARO}\strut
\end{minipage} & \begin{minipage}[t]{0.08\columnwidth}\raggedright\strut
Argentina (15) Brazil (30) Canada (8) Chile (5) Colombia (6) Costa Rica
(3) Cuba (2) Dominican Republic (4) Ecuador (3) Honduras (2) Mexico (16)
Nicaragua (1) Panama (1) Paraguay (4) Peru (1) United States of America
(39) Venezuela (1)\strut
\end{minipage} & \begin{minipage}[t]{0.08\columnwidth}\raggedright\strut
141\strut
\end{minipage} & \begin{minipage}[t]{0.08\columnwidth}\raggedright\strut
55.2\strut
\end{minipage} & \begin{minipage}[t]{0.08\columnwidth}\raggedright\strut
0.83\strut
\end{minipage} & \begin{minipage}[t]{0.08\columnwidth}\raggedright\strut
Allergist (81.5) Clinical Immunologist (9.2) Dermatologist (1.4) ENT
(1.4) Paediatrician (4.2) Researcher (1.4) Other (0.9)\strut
\end{minipage} & \begin{minipage}[t]{0.08\columnwidth}\raggedright\strut
51.7\strut
\end{minipage} & \begin{minipage}[t]{0.08\columnwidth}\raggedright\strut
74.5\strut
\end{minipage} & \begin{minipage}[t]{0.08\columnwidth}\raggedright\strut
Private (49.0) Public (18.4) Both (32.6)\strut
\end{minipage} & \begin{minipage}[t]{0.08\columnwidth}\raggedright\strut
Yourself (68.8) A staff member / institution (18.0) Nobody (9.2) I don't
know (4.2)\strut
\end{minipage} & \begin{minipage}[t]{0.08\columnwidth}\raggedright\strut
ICD-10 (+ adaptation) (69.5) ICD-9 (+ adaptation) (7.0) SNOMED-CT (0.7)
Read Codes (3.5) None (17.0) Other (2.3)\strut
\end{minipage} & \begin{minipage}[t]{0.08\columnwidth}\raggedright\strut
Yes (31.2) No (68.8)\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.08\columnwidth}\raggedright\strut
\textbf{EMRO}\strut
\end{minipage} & \begin{minipage}[t]{0.08\columnwidth}\raggedright\strut
Egypt (6) Iran (1) Jordan (1) Lebanon (3) Morocco (1) Pakistan (3) Saudi
Arabia (2) Tunisia (1)\strut
\end{minipage} & \begin{minipage}[t]{0.08\columnwidth}\raggedright\strut
18\strut
\end{minipage} & \begin{minipage}[t]{0.08\columnwidth}\raggedright\strut
49.3\strut
\end{minipage} & \begin{minipage}[t]{0.08\columnwidth}\raggedright\strut
0.80\strut
\end{minipage} & \begin{minipage}[t]{0.08\columnwidth}\raggedright\strut
Allergist (50) Clinical Immunologist (5.5) Paediatrician (22.5) Primary
care (5.5) Pulmonologist (5.5) Researcher (5.5) Other (5.5)\strut
\end{minipage} & \begin{minipage}[t]{0.08\columnwidth}\raggedright\strut
38.9\strut
\end{minipage} & \begin{minipage}[t]{0.08\columnwidth}\raggedright\strut
44.5\strut
\end{minipage} & \begin{minipage}[t]{0.08\columnwidth}\raggedright\strut
Private (33.3) Public (33.3) Both (33.4)\strut
\end{minipage} & \begin{minipage}[t]{0.08\columnwidth}\raggedright\strut
Yourself (50) A staff member / institution (11.1) Nobody (33.3) I don't
know (4.7)\strut
\end{minipage} & \begin{minipage}[t]{0.08\columnwidth}\raggedright\strut
ICD-10 (+ adaptation) (22.2) ICD-9 (+ adaptation) (0.0) SNOMED-CT (0.0)
Read Codes (5.6) None (72.2) Other (0.0)\strut
\end{minipage} & \begin{minipage}[t]{0.08\columnwidth}\raggedright\strut
Yes (38.9) No (61.1)\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.08\columnwidth}\raggedright\strut
\textbf{EURO}\strut
\end{minipage} & \begin{minipage}[t]{0.08\columnwidth}\raggedright\strut
Albania (1) Armenia (2) Austria (6) Belarus (1) Belgium (7) Bulgaria (5)
Croatia (5) Czech Republic (2) Denmark (1) Finland (1) France (20)
Georgia (2) Germany (5) Greece (11) Hungary (1) Israel (3) Italy (20)
Lithuania (2) Netherlands (3) Poland (3) Portugal (22) Romania (12)
Russian Federation (1) Serbia (9) Slovenia (1) Spain (26) Sweden (1)
Switzerland (1) Turkey (5) Ukraine (3) United Kingdom (12)\strut
\end{minipage} & \begin{minipage}[t]{0.08\columnwidth}\raggedright\strut
189\strut
\end{minipage} & \begin{minipage}[t]{0.08\columnwidth}\raggedright\strut
48.7\strut
\end{minipage} & \begin{minipage}[t]{0.08\columnwidth}\raggedright\strut
1.07\strut
\end{minipage} & \begin{minipage}[t]{0.08\columnwidth}\raggedright\strut
Allergist (69.8) Clinical Immunologist (4.2) Dermatologist (6.3) ENT
(0.5) Paediatrician (11.0) Primary care (1.0) Pulmonologist (5.2)
Researcher (1.0) Other (1.0)\strut
\end{minipage} & \begin{minipage}[t]{0.08\columnwidth}\raggedright\strut
46.5\strut
\end{minipage} & \begin{minipage}[t]{0.08\columnwidth}\raggedright\strut
68.8\strut
\end{minipage} & \begin{minipage}[t]{0.08\columnwidth}\raggedright\strut
Private (14.3) Public (51.3) Both (34.4)\strut
\end{minipage} & \begin{minipage}[t]{0.08\columnwidth}\raggedright\strut
Yourself (53.0) A staff member / institution (30.1) Nobody (10.0) I
don't know (6.9)\strut
\end{minipage} & \begin{minipage}[t]{0.08\columnwidth}\raggedright\strut
ICD-10 (+ adaptation) (72.0) ICD-9 (+ adaptation) (0.5) SNOMED-CT (1.0)
Read Codes (1.6) None (19.6) Other (5.3)\strut
\end{minipage} & \begin{minipage}[t]{0.08\columnwidth}\raggedright\strut
Yes (28.0) No (72.0)\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.08\columnwidth}\raggedright\strut
\textbf{SEARO}\strut
\end{minipage} & \begin{minipage}[t]{0.08\columnwidth}\raggedright\strut
India (5) Indonesia (2) Sri Lanka (2) Thailand (10)\strut
\end{minipage} & \begin{minipage}[t]{0.08\columnwidth}\raggedright\strut
19\strut
\end{minipage} & \begin{minipage}[t]{0.08\columnwidth}\raggedright\strut
41.4\strut
\end{minipage} & \begin{minipage}[t]{0.08\columnwidth}\raggedright\strut
1.37\strut
\end{minipage} & \begin{minipage}[t]{0.08\columnwidth}\raggedright\strut
Allergist (73.7) Clinical Immunologist (5.2) Paediatrician (10.5)
Pulmonologist (5.2) Researcher (5.2)\strut
\end{minipage} & \begin{minipage}[t]{0.08\columnwidth}\raggedright\strut
21.0\strut
\end{minipage} & \begin{minipage}[t]{0.08\columnwidth}\raggedright\strut
31.6\strut
\end{minipage} & \begin{minipage}[t]{0.08\columnwidth}\raggedright\strut
Private (15.8) Public (21.0) Both (63.2)\strut
\end{minipage} & \begin{minipage}[t]{0.08\columnwidth}\raggedright\strut
Yourself (47.3) A staff member / institution (26.3) Nobody (21.0) I
don't know (5.4)\strut
\end{minipage} & \begin{minipage}[t]{0.08\columnwidth}\raggedright\strut
ICD-10 (+ adaptation) (73.7) ICD-9 (+ adaptation) (0.0) SNOMED-CT (0.0)
Read Codes (0.0) None (21.0) Other (5.3)\strut
\end{minipage} & \begin{minipage}[t]{0.08\columnwidth}\raggedright\strut
Yes (31.5) No (68.5)\strut
\end{minipage}\tabularnewline
\begin{minipage}[t]{0.08\columnwidth}\raggedright\strut
\textbf{WPRO}\strut
\end{minipage} & \begin{minipage}[t]{0.08\columnwidth}\raggedright\strut
Australia (14) Brunei Darussalam (1) China (1) Japan (1) Malaysia (5)
Philippines (1) Democratic People's Republic of Korea (4) Viet Nam
(3)\strut
\end{minipage} & \begin{minipage}[t]{0.08\columnwidth}\raggedright\strut
32\strut
\end{minipage} & \begin{minipage}[t]{0.08\columnwidth}\raggedright\strut
49.5\strut
\end{minipage} & \begin{minipage}[t]{0.08\columnwidth}\raggedright\strut
0.45\strut
\end{minipage} & \begin{minipage}[t]{0.08\columnwidth}\raggedright\strut
Allergist (46.8) Clinical Immunologist (21.8) Dermatologist (9.3) ENT
(3.2) Paediatrician (12.5) Pulmonologist (3.2) Researcher (3.2)\strut
\end{minipage} & \begin{minipage}[t]{0.08\columnwidth}\raggedright\strut
46.8\strut
\end{minipage} & \begin{minipage}[t]{0.08\columnwidth}\raggedright\strut
40.6\strut
\end{minipage} & \begin{minipage}[t]{0.08\columnwidth}\raggedright\strut
Private (28.1) Public (40.6) Both (31.3)\strut
\end{minipage} & \begin{minipage}[t]{0.08\columnwidth}\raggedright\strut
Yourself (37.5) A staff member / institution (40.6) Nobody (18.7) I
don't know (3.2)\strut
\end{minipage} & \begin{minipage}[t]{0.08\columnwidth}\raggedright\strut
ICD-10 (+ adaptation) (50) ICD-9 (+ adaptation) (3.1) SNOMED-CT (6.2)
Read Codes (0.0) None (37.5) Other (3.2)\strut
\end{minipage} & \begin{minipage}[t]{0.08\columnwidth}\raggedright\strut
Yes (37.5) No (62.5)\strut
\end{minipage}\tabularnewline
\bottomrule
\end{longtable}

Table 2: Responses to open ended questions from a web international
survey fielded in 2019: what is expected by a classification system and
what the ICD-11 is able to bring\selectlanguage{english}
\begin{longtable}[]{@{}ll@{}}
\toprule
\textbf{What is expected from a classification system (N, \%)*}
\textbf{*292 responses} & \textbf{The ICD-11 will be able to (N, \%)**}
\textbf{**406 responses}\tabularnewline
\midrule
\endhead
\textbf{Inclusion of some missing allergic diseases (220, 75.3)} &
\textbf{Allow more accurate representation of allergic and
hypersensitivity conditions (313, 77.1)}\tabularnewline
\textbf{Inclusion of the diseases with overlapping classification
(example: Asthma induced by Aspirin) (187, 64.0)} & \textbf{Support
harmonization of terminology and definitions in the field of allergy
(231, 56.9)}\tabularnewline
\textbf{Inclusion of explicit diagnostic criteria (115, 39.4)} &
\textbf{Support correct diagnosis and management (201,
49.5)}\tabularnewline
\textbf{Inclusion of causes (99, 33.9)} & \textbf{Allow estimate the
burden of allergic and hypersensitivity conditions (191,
47.0)}\tabularnewline
\textbf{Inclusion of symptoms (68, 23.2)} & \textbf{Allow comparability
of morbidity and mortality statistics (175, 43.1)}\tabularnewline
\textbf{No suggestions (13, 4.4)} & \textbf{Support allocation of
resources for the management and prevention of allergic and
hypersensitivity conditions (170, 41.9)}\tabularnewline
\textbf{Other (15, 5.1)} & \textbf{Support decision-making tools and
actions (150, 36.9)}\tabularnewline
& \textbf{Allow following patients across the health care pathways (130,
32.0)}\tabularnewline
\bottomrule
\end{longtable}

\selectlanguage{english}
\FloatBarrier
\end{document}

