The Allergy in ICD-11 initiative
Over the past 7 years, a detailed action plan was developed and
implemented under the ALLERGY in ICD-11 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 11threvision. 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 Allergic and hypersensitivity conditionssection within the newly created chapter, 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 (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 72nd 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 1st January 2022, some countries such as the
US may take longer to fully adopt ICD-11.