Supporting the validation of the new allergic and hypersensitivity conditions section of the World Health Organization International Classification of Diseases-11

Epidemiology of anaphylaxis: is the trend still going up?

PURPOSE OF REVIEW

To understand the current global scale of anaphylaxis and identify possible strategies to increase the accuracy of epidemiological data.

RECENT FINDINGS

Anaphylaxis mortality and morbidity statistics may gain new perspectives with the global implementation of the ICD-11. Improving the quality of epidemiological data related to anaphylaxis should clarify some areas of uncertainty about risk factors, leading to better targeting of strategies to protect those patients at risk, and support decision-making to facilitate health care planning and implementation of public health measures to prevent anaphylaxis.

SUMMARY

The true rate of anaphylaxis is unknown due to a number of factors, such as misdiagnosis, miscoding and undernotification. Moreover, there is lack of information about anaphylaxis epidemiology in many countries. Difficulties on collecting accurate and comparable data should be acknowledged and anaphylaxis data can vary widely. Currently, most robust data are derived from hospitalization datasets and national mortality databases. Anaphylaxis accounts for up to 0.26% of overall hospital admissions. It is suggested that the number of hospital admissions for anaphylaxis is increasing in many countries, both with respect to all-causes of anaphylaxis and by trigger, but the mortality rate remains low. However, there are still great challenges in capturing quality anaphylaxis mortality and morbidity statistics. Better understanding of anaphylaxis trends should clarify some areas of uncertainty about risk factors and prospect effective prevention strategies. As the knowledge derived from populations is key information for more realistic decision-making, the construction of the new section addressed to anaphylaxis in the ICD-11 will allow the collection of more accurate epidemiological data to support high quality management of patients, and to better facilitate health care planning to implement public health measures, reduce the morbidity and mortality attributable to anaphylaxis.

A retrospective study on the incidence, management and risk factors of skin rash in patients with advanced prostate cancer in Japan

BACKGROUND

Worldwide, prostate cancer (PC) is the second most diagnosed cancer and the fifth leading cause of cancer death in men. Hormonal therapies, commonly used for PC, are associated with a range of treatment-emergent adverse events (TEAEs). The population from Japan seems to be at higher risk of developing TEAEs of skin rash compared to the overall global population. This study was conducted to get a better insight into the incidence, management, and risk factors for skin rash during active treatment for advanced PC in Japan.

METHODS

A retrospective cohort of PC patients was identified and subsequently categorized, into non-metastatic and metastatic castration-resistant prostate cancer patients (nmCRPC and mCRPC), and metastatic castration-naïve prostate cancer patients (mCNPC). The analysis was based on a dataset from the Medical Data Vision (MDV) database. Descriptive statistics were determined, and a multivariate Cox proportional hazards model was used to the associated risk factors for the onset of rash.

RESULTS

Overall, 1,738 nmCRPC patients, 630 mCRPC patients, and 454 mCNPC patients were included in this analysis. The median age was 78 years old and similar across the three cohorts. The skin rash incidence was 19.97% for nmCRPC cohort, 28.89% for mCRPC cohort, and 28.85% for mCNPC cohort. The median duration of skin rash ranged from 29 to 42 days. Statistically significant risk factors for developing skin rash included a history of allergy or hypersensitivity (all cohorts), increased age (nmCRPC and mCRPC), a body mass index (BMI) of < 18.5 (nmCRPC and mCRPC), and a PSA level higher than the median (nmCRPC). Skin rash was commonly managed with systemic and topical corticosteroids which ranged from 41.76% to 67.03% for all cohorts. Antihistamines were infrequently used.

CONCLUSION

This study provides a better understanding of the real-world incidence, onset, duration, management and risk factors of skin rash in patients on active PC treatment in Japan. It was observed that approximately 20-30% of PC patients experience skin rash. Development of skin rash was associated with previous allergy or hypersensitivity, BMI of < 18.5, increased age and higher PSA levels, and was usually treated with corticosteroids.

Food allergy in the World Health Organization's International Classification of Diseases (ICD)-11

There are increasing global data regarding the prevalence of food allergy and food-induced anaphylaxis. However, knowledge in morbidity and mortality epidemiological data is still not optimal, and international comparable standards remain poorly accessed. This information could in turn support better clinical practice and possibly prevent future severe reactions and avoidable fatalities. The International Classification of Diseases (ICD) is the standard diagnostic tool used for epidemiology, health management, and clinical purposes supported by the World Health Organization (WHO). It is also used to determine health care payment and reimbursement of providers and health care services in hospitals. Thanks to the academic and technical efforts under the ALLERGY in ICD-11 initiative the pioneer "Allergy and hypersensitivity conditions" section has been built under the "Disorders of the Immune System" chapter of the ICD-11. The "Food hypersensitivity" (FH) subsection is classified under the "Complex allergic or hypersensitivity conditions" section and "Food-induced anaphylaxis" is under the "Anaphylaxis" section. In order to inform the development of strategies to reduce preventable FHs/food allergies, the burden of disease in different healthcare settings and patient populations and their common etiologies need to be understood. Besides, greater specificity regarding clinical conditions and services delivered will provide payers, policy makers, and providers with better information to make major refinements to countries payment and reimbursement systems, including the design and implementation of pay-for-performance program.The new classification addressed to FHs will enable the collection of more accurate epidemiological data to support quality management of patients with FHs/food allergies, and better facilitate health care planning and decision-making and public health measures to prevent and reduce their morbidity and mortality. The improved logic and standardized definitions through the ICD-11 (and other WHO classifications) will also facilitate international comparisons of quality care and the sharing of best practice globally.

Epidemiology of anaphylaxis

PURPOSE OF REVIEW

To understand the current global epidemiological data of anaphylaxis and identify potential strategies to improve patients' care and prevention.

RECENT FINDINGS

Anaphylaxis mortality and morbidity statistics (MMS) may gain new perspectives with the implementation of the International Classification of Diseases (ICD)-11 in the forthcoming years. Improving the quality of epidemiological data related to anaphylaxis should clarify some areas of uncertainty about risk factors, leading to better targeting of strategies to protect those patients at risk, and support decision-making to facilitate healthcare planning and implementation of public health measures to prevent anaphylaxis.

SUMMARY

Anaphylaxis is a complex noncommunicable diseases with adverse impact on health-related quality of life of patients and their carriers and a significant proportion of deaths may be preventable. It requires an integrated holistic plan to improve quality of healthcare and gathering accurate and comparable epidemiological data is key. Morbidity related to anaphylaxis seems to be increasing worldwide whereas mortality of anaphylaxis appears to be low and stable, but this still has great challenges in capturing quality anaphylaxis MMS. Improving the quality of epidemiological data related to anaphylaxis should clarify some areas of uncertainty about risk factors, leading to better targeting of strategies to protect those patients at risk. As knowledge derived from populations is key information for more realistic decision-making, the construction of the new section addressed to anaphylaxis in the ICD-11 will allow the collection of more accurate epidemiological data to support quality management of patients, and better facilitate healthcare planning to implement public health measures to prevent and reduce the morbidity and mortality attributable to these conditions.

Global implementation of the world health organization's International Classification of Diseases (ICD)-11: The allergic and hypersensitivity conditions model

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 subsections 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.

Changing the history of anaphylaxis mortality statistics through the World Health Organization's International Classification of Diseases-11

We review the history of the classification and coding changes for anaphylaxis and provide current and perspective information in the field. In 2012, an analysis of Brazilian data demonstrated undernotification of anaphylaxis-related deaths because of the difficulties of coding using the International Classification of Diseases, 10th Revision. This work triggered strategic international actions supported by the Joint Allergy Academies and the International Classification of Diseases World Health Organization (WHO) leadership to update the classification of allergic disorders for the International Classification of Diseases, 11th Revision (ICD-11), which resulted in construction of the pioneer "Allergic and hypersensitivity conditions" chapter. The usability of the new framework has been tested by evaluating the same data published in 2012 from the ICD-11 perspective. Coding accuracy was much improved, reaching 95% for definite anaphylaxis. As the results were provided to the WHO Mortality Reference Group, coding rules have been changed, allowing anaphylaxis to be recorded as an underlying cause of death in official mortality statistics. The mandatory use of ICD-11 from January 2022 for documenting cause of death could have 2 immediate consequences: (1) the reported number of anaphylaxis-related deaths might increase because of more appropriate coding and (2) the cross-sectional and longitudinal mortality data generated might ultimately lead to a better understanding of anaphylaxis epidemiology and improved health policies directed at reducing anaphylaxis-related mortality.

What can we learn in drug allergy management from World Health Organization's international classifications?

Drug hypersensitivity reactions (DHRs) represent growing health problem worldwide, affecting more than 7% of the general population, and represent an important public health problem. However, knowledge in DHRs morbidity and mortality epidemiological data is still not optimal and international comparable standards remain poorly accessed. Institutional databases worldwide increasingly use the WHO International Classification of Diseases (ICD) system to classify diagnoses, health services utilization, and death data. The misclassification of disorders in the ICD system contributes to a lack of ascertainment and recognition of their importance for healthcare planning and resource allocation. It also hampers clinical practice and prevention actions. To further inform the allergy community and to ensure that the revision process is transparent as advised in the WHO ICD-11 revision agenda, we report the advances and use of the pioneering "Drug hypersensitivity" subsection of ICD-11 and implementation in the WHO International Classification of Health Interventions (ICHI). The new classification addressed to DHRs will enable the collection of more accurate epidemiological data to support quality management of patients with drug allergies and better facilitate healthcare planning and decision-making and public health measures to prevent and reduce the morbidity and mortality attributable to DHRs.

Critical view of anaphylaxis epidemiology: open questions and new perspectives

In contrast to the majority of allergic or hypersensitivity conditions, worldwide anaphylaxis epidemiological data remain sparse with low accuracy, which hampers comparable morbidity statistics. Data can differ widely depending on a number of variables. In the current document we reviewed the forms on which anaphylaxis has been defined and classified; and how it can affect epidemiological data. With regards to the methods used to capture morbidity statistics, we observed the impact of the anaphylaxis coding utilizing the World Health Organization's International Classification of Diseases. As an outcome and depending on the anaphylaxis definition, we extracted the cumulative incidence, which may not reflect the real number of new cases. The new ICD-11 anaphylaxis subsection developments and critical view of morbidity statistics data are discussed in order to reach new perspectives on anaphylaxis epidemiology.

Implementation gaps for asthma prevention and control

Asthma and allergic diseases can start in childhood and persist throughout life, but could also be manifested later, at any time for still misunderstood reasons. They are major chronic multifactorial respiratory diseases, for which prevention, early diagnosis and treatment is recognized as a priority for the Europe's public health policy and the United Nations. Given that allergy triggers (including infections, rapid urbanization leading to loss in biodiversity, pollution and climate changes) are not expected to change in a foreseeable future, it is imperative that steps are taken to develop, strengthen and optimize preventive and treatment strategies. Currently there are good treatments for asthma, several risk factors are known (e.g., allergies, rhinitis, tobacco smoke) and tools to control the disease have been developed. However, we are still uncertain how to prevent patients from developing asthma and allergic diseases. In this paper, we list the positive and negative experiences in this field as well as analyze the missing links in the process. This critical analysis will be the basis of setting-up an effective program for prevention and making, a process labeled as "implementation gaps".

Field-testing the new anaphylaxis' classification for the WHO International Classification of Diseases-11 revision

BACKGROUND

To consolidate the new classification model addressed to the allergic and hypersensitivity conditions according to the International Classification of Diseases (ICD)-11 revision timeline, we here propose real-life application of quality assurance methodology to evaluate sensitivity and accuracy of the 'Anaphylaxis' subsection.

METHODS

We applied field-testing methodology by analysing all the consecutive inpatients' files documented as allergies from the University Hospital of Montpellier electronic database for the period of 1 year. The files clinically validated as being anaphylaxis were manually blind-coded under ICD-10 and current ICD-11 beta draft. The correspondence of coding and the impressions regarding sensibility were evaluated.

RESULTS

From all 2318 files related to allergic or hypersensitivity conditions, 673 had some of the anaphylaxis ICD-10 codes; 309 files (46%) from 209 patients had anaphylaxis and allergic or hypersensitivity comorbidities description. The correspondence between the two coders was perfect for 162 codes from all 309 entities (52.4%) (Cohen-kappa value 0.63) with the ICD-10 and for 221 codes (71.5%) (Cohen-kappa value 0.77) with the ICD-11. There was a high agreement regarding sensibility of the ICD-11 usability (Cohen-kappa value 0.75).

CONCLUSION

We here propose the first attempt of real-life application to validate the new ICD-11 'Anaphylaxis' subsection. Clearer was the improvement in accuracy reaching 71.5% of agreement when ICD-11 was used. By allowing all the relevant diagnostic terms for anaphylaxis to be included into the ICD-11 framework, WHO has recognized their importance not only to clinicians but also to epidemiologists, statisticians, healthcare planners and other stakeholders.

Fatal anaphylaxis registries data support changes in the who anaphylaxis mortality coding rules

Anaphylaxis is defined as a severe life-threatening generalized or systemic hypersensitivity reaction. The difficulty of coding anaphylaxis fatalities under the World Health Organization (WHO) International Classification of Diseases (ICD) system is recognized as an important reason for under-notification of anaphylaxis deaths. On current death certificates, a limited number of ICD codes are valid as underlying causes of death, and death certificates do not include the word anaphylaxis per se. In this review, we provide evidences supporting the need for changes in WHO mortality coding rules and call for addition of anaphylaxis as an underlying cause of death on international death certificates. This publication will be included in support of a formal request to the WHO as a formal request for this move taking the 11^th ICD revision.