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.