Hospitalization Due to Asthma Exacerbation: A China Asthma Research Network (CARN) Retrospective Study in 29 Provinces Across Mainland China

Meteorological factors and climate change impact on asthma: a systematic review of epidemiological evidence

OBJECTIVE

This systematic review aimed to investigate the epidemiological data about meteorological factors and climate change (CC) impact on asthma.

DATA SOURCES

A search was performed using three databases (Web of Science, Science Direct, and MEDLINE) for all relevant studies published from January 1, 2018, to December 31, 2022.

STUDY SELECTIONS

This systematic review complied with the PRISMA document's requirements, including studies related to meteorological factors and CC impact on asthma. The search included studies published in English or French language, and was based on title, abstract, and complete text. Documents not meeting inclusion requirements were excluded.

RESULTS

We identified 18 studies published in the last five years that were eligible for inclusion in this review. We found that these studies concerned European, Asian, American, and Oceanic cities. Extreme variations in temperature, humidity, wind speed, exceptional incidents like hurricanes, cold and heat waves, and seasonal shifts were strongly correlated with the worsening of asthmatic symptoms, particularly in childhood. In addition, excessive concentrations of air pollutants and aeroallergens were linked to pediatric asthma emergency hospital admissions.

CONCLUSIONS

A significant association between the consequences of CC and asthma in adults particularly in children has been demonstrated. Future research should quantify the impact of global change in climate regarding the aeroallergens' distribution in terms of geography and time. It is also necessary to research the impact of air pollution on asthmatic health, like sulfur dioxide (SO2), nitrogen dioxide (NO2), ozone (O3), and particles having an aerodynamic diameter lower than 2.5 µm (PM2.5).

Utilizing EMR Data for Smoking Behavior Surveillance in Hospitalized Patients With Chronic Respiratory Diseases and Its Impact on Clinical Outcomes - Beijing Municipality, China, 2014-2023

What is already known on this topic?

Smoking is the primary risk factor for a poor prognosis in chronic respiratory disease (CRD). Current tobacco surveillance efforts in China focus on the general population and do not adequately cover CRD patients.

What is added by this report?

We employed electronic medical records (EMR) to track smoking habits in 28,334 hospitalized CRD patients at Beijing Chao-Yang Hospital. The rates of former and current smokers were 30.7% and 18.0%, respectively. Both former and current smokers exhibited an increased risk of respiratory symptoms and extended hospital stays.

What are the implications for public health practice?

These results underscore the importance of implementing smoking monitoring and targeted cessation interventions for hospitalized patients with CRDs.

Cost-effectiveness of mepolizumab for severe eosinophilic asthma in China

OBJECTIVE

To evaluate the economic value of mepolizumab as an add-on therapy to the standard of care (SoC) for patients with severe eosinophilic asthma in China.

METHODS

A Markov model with three health conditions was constructed to calculate the incremental cost per quality-adjusted life year (QALY) in mepolizumab with SoC and SoC only groups from the perspective of the Chinese healthcare system throughout an entire lifespan. The model was populated with local costs, while efficacy parameters were obtained from the global Phase III MENSA trial and mortality was derived from two surveys. One-way and probabilistic sensitivity analyses were conducted. Additional scenario analysis was used to estimate the cost-effectiveness impact of changes in the price of mepolizumab.

RESULTS

Over the lifetime treatment horizon, the incremental cost-effectiveness ratio (ICER) of mepolizumab plus SoC compared to SoC alone was $170 648.73 per QALY. Sensitivity analyses focused on these results. Scenario analysis showed that mepolizumab would require a price reduction of at least 82% to reach the current willingness-to-pay (WTP=$38 223.34/QALY) threshold.

CONCLUSION

Mepolizumab is not a cost-effective healthcare resource in China at its current pricing.

Efficacy and safety of intravenous leukotriene receptor antagonists in acute asthma

The incidence of bronchial asthma has increased substantially since recent decades in both children and adults. Moreover, the number of patients presenting with asthma exacerbation to the emergency department has also increased in several countries. Leukotrienes are inflammatory mediators that play an important role in bronchial asthma exacerbation. Leukotriene receptor antagonists reduce asthma exacerbation in chronic asthma; moreover, the current guidelines for asthma management recommend the use of oral leukotriene receptor antagonists for asthma control and reduce further exacerbation. However, data on the use of intravenous leukotriene receptor antagonists during acute asthma exacerbation are scarce. Nevertheless, currently available data revealed a trend of significant improvement of acute asthma and rapid reversal of airflow obstruction when administered during an acute asthma attack. This review aims to summarize currently available data on the use of intravenous leukotriene receptor antagonists in adult patients with acute asthma exacerbation.

Illness Perceptions and Self-Management among People with Chronic Lung Disease and Healthcare Professionals: A Mixed-Method Study Identifying the Local Context

Self-management interventions (SMIs) may fail if they misalign with the local context. To optimize the implementation of SMIs in Chinese people with chronic lung disease (CLD), the local context was identified in Chinese primary care (PC) and secondary care (SC). A mixed-method study using semi-structured interviews and quantitative surveys was conducted on people with CLD and healthcare professionals (HCPs). The qualitative data was collected until data saturation was reached, and participants were invited to complete the survey after the interview. The qualitative data—analyzed with the framework approach—was triangulated with the quantitative data. A total of 52 participants completed the interviews, and 48 also finished the survey. Four themes were identified; (a) illness perceptions (e.g., patients had poor CLD knowledge and SM, inadequate resources lead to suboptimal disease control in PC); (b) self-management skills (e.g., most patients delayed exacerbation recognition and action, and some were admitted at the crisis point); (c) factors influencing self-management skills (e.g., (in)adequate disease knowledge and medical expenditure affordability); and (d) needs for self-management (e.g., increased disease knowledge, individualized self-management plan, eHealth, (healthcare insurance) policy support). Identified themes were dependent on each other and should be leveraged when implementing SMIs. Ultimately, such SMIs can optimize patient health outcomes.

Associations between comorbidities and annual incidence plus frequency of asthma exacerbation hospitalisation during the past year: data from CARN study

Purpose

While asthma comorbidities are associated with higher health care utilisation, lower quality of life and poorer asthma control, the impact of asthma comorbidities on hospitalisation for asthma exacerbation (H-AX) remains less recognised. We aim to analyse the impact of asthma comorbidities on H-AX.

Methods

Based on a national survey on asthma control and disease perception (CARN 2015 study), we analysed the impact of comorbidities on annual incidence and frequency of H-AX in China. Information on demographic characteristics, asthma comorbidities and annual incidence and frequency of H-AX were presented in this study.

Results

Among 3875 ambulatory asthma patients, 75.9% (2941/3875) had comorbidities, and 26.4% (1017/3858) experienced H-AX during past year. After adjusting for confounding factors such as demographic data, smoking status and asthma control, COPD [OR = 2.189, 95% CI (1.673, 2.863)] and coronary heart disease [OR = 1.387, 95% CI (1.032, 1.864)] were associated with higher annual incidence, while allergic rhinitis [OR = 0.692, 95% CI (0.588, 0.815)] was associated with lower annual incidence, of H-AX. In terms of frequency, allergic rhinitis [OR = 1.630, 95% CI (1.214, 2.187)], COPD [OR = 1.472, 95% CI (1.021, 2.122)] and anxiety [OR = 2.609, 95% CI (1.051, 6.477)] showed statistically significant correlation with frequent H-AX.

Conclusions

COPD and coronary heart disease were associated with higher annual incidence, while allergic rhinitis was associated with lower annual incidence of H-AX. Allergic rhinitis, COPD and anxiety were associated with frequent H-AX. Comorbidities may have an important role in the risk and frequency of annual hospitalisations due to asthma exacerbation. The goal of asthma control should rely on a multi-disciplinary treatment protocol.

Reduced bronchodilator reversibility correlates with non-type 2 high asthma and future exacerbations: A prospective cohort study

BACKGROUND

Given that airway obstruction in asthma is not always fully reversible, reduced bronchodilator reversibility (BDR) may be a special asthma phenotype.

OBJECTIVE

To explore the characteristics of BDR^high/low phenotypes (defined using two BDR criteria) and their associations with asthma exacerbations (AEs).

METHODS

After baseline assessments, all patients were classified into BDR^high or BDR^low phenotypes. This study consisted of 2 parts. Part I was a 12-month prospective observational cohort study designed to identify the clinical characteristics and associations with future AEs in BDR^high/low phenotypes (n = 456). Part II, designed as a post hoc analysis of the data obtained in Part I, was conducted to assess the association between BDR^high/low phenotypes and treatment responsiveness (n = 360).

RESULTS

Subjects with BDR^low phenotypes had better baseline asthma symptom control and was negatively associated with eosinophilic asthma and type 2 (T2) high asthma. During the 12-month follow-up, those with BDR^low phenotypes had a higher risk of severe AEs (SAEs) (guideline-based criterion: RR_adj = 2.24, 95% CI = [1.25, 3.68]; Ward's criterion: RR_adj = 2.46, 95% CI = [1.40, 4.00]) and moderate-to-severe AEs (MSAEs) (guideline-based criterion: RR_adj = 1.83, 95% CI = [1.22, 2.56]; Ward's criterion: RR_adj = 1.94, 95% CI = [1.32, 2.68]) in the following year according to logistic regression models. Similar findings were obtained with negative binominal regression models. BDR^low phenotype was a risk factor for an insensitive response to anti-asthma treatment (guideline-based criterion: OR_adj = 1.96, 95% CI = [1.05, 3.65]; Ward's criterion: OR_adj = 2.01, 95% CI = [1.12, 3.58]).

CONCLUSION

We identified that BDR^low phenotype was associated with non-T2 high asthma and future AEs. These findings have clinically relevant implications for asthma management.

REducing delay through edUcation on eXacerbations for people with chronic lung disease: Study protocol of a single-arm pre-post study

AIM

This study protocol aims to examine the effectiveness and preconditions of a self-management program-named REducing Delay through edUcation on eXacerbations (REDUX)-in China.

BACKGROUND

The high disease burden in people with chronic lung disease is mainly due to exacerbations. There is a need for effective exacerbation-management interventions. A nurse-led program, REDUX, helped patients self-manage exacerbations.

DESIGN

A single-arm pre-post study.

METHODS

Fifty-four patients and 24 healthcare professionals (HCPs) in Chinese primary care will be included. The core element of the program is a personalized action plan. HCPs will receive training in using the action plan to help patients manage exacerbations. The intervention will start when a patient is referred to the nurse for a post-exacerbation consultation and ends when the patient presents for the second post-exacerbation consultation. During the first post-exacerbation consultation, the patient and nurse will create the action plan. The primary outcomes in patients will include the delays between the onset of exacerbation and recognition, between exacerbation recognition and action, between exacerbation recognition and consultation with a doctor, and when the patients feel better after receiving medical help from HCPs. The secondary outcomes will include preconditions of the program. The ethics approval was obtained in September 2021.

DISCUSSION

This study will discuss a culturally adapted nurse-led self-management intervention for people with chronic lung disease in China. The intervention could help Chinese HCPs provide efficient care and reduce their workload. Furthermore, it will inform future research on tailoring nurse-led self-management interventions in different contexts.

IMPACT

The study will contribute to the evidence on the effectiveness and preconditions of REDUX in China. If effective, the result will assist the nursing of people with chronic lung disease.

TRIAL REGISTRATION

Registered in the Chinese clinical trial registry (ID: 2100051782).

Association of genetic variants of oxidative stress responsive kinase 1 (OXSR1) with asthma exacerbations in non-smoking asthmatics

BACKGROUND

Asthma exacerbation threatens patient's life. Several genetic studies have been conducted to determine the risk factors for asthma exacerbation, but this information is still lacking. We aimed to determine whether genetic variants of Oxidative Stress Responsive Kinase 1 (OXSR1), a gene with functions of salt transport, immune response, and oxidative stress, are associated with exacerbation of asthma.

METHODS

Clinical data were obtained from 1454 asthmatics and single nucleotide polymorphisms (SNPs) of OXSR1 were genotyped. Genetic associations with annual exacerbation rate were analyzed depending on smoking status.

RESULTS

Eleven SNPs were selected using Asian data in the International HapMap database. The common allele of rs1384006 C > T of OXSR1 showed a significantly higher annual exacerbation rate than the rare allele in non-smoking asthmatics (CC vs. CT vs. TT: 0.43 ± 0.04 vs. 0.28 ± 0.03 vs. 0.31 ± 0.09, P = 0.004, Pcorr = 0.039). The frequent exacerbators had a significantly higher frequency of the common allele of rs1384006 C > T than did the infrequent exacerbators (74.4% vs. 55.2%, P = 0.004, Pcorr = 0.038).

CONCLUSION

The common allele of rs1384006 C > T of OXSR1 was associated with the asthma exacerbation rate and a higher risk of being a frequent exacerbator, indicating that non-smoking asthmatics who carry common alleles may be vulnerable to asthma exacerbations.

Variability of Type 2 inflammatory markers guiding biologic therapy of severe asthma: A 5-year retrospective study from a single tertiary hospital

Background

Currently, biotherapy is mainly administered to treat patients with severe asthma with the Type 2 (T2) inflammation phenotype. The variability of T2 inflammatory markers remains poorly understood.

Objective

We aimed to describe the individual distributions of different biomarkers at varying thresholds and their variation patterns in participants with severe asthma.

Methods

We retrospectively reviewed the data of participants who had completed 2 or more fraction of exhaled nitric oxide (FeNO) and peripheral blood eosinophil counts in our centre within 5 years. The individual distribution of biomarkers (blood or sputum eosinophils, FeNO, and serum total IgE) with repeated measurements at different thresholds was analysed. The varied patterns of biomarkers were analysed by cluster analysis.

Results

A total of 241 eligible participants were screened. Through long-term longitudinal multiple measurements, we found that approximately 50% of severe asthmatics had blood eosinophil levels fluctuating around the threshold defined by biological agents. FeNO persisted at levels >19.5 ppb or 25 ppb in more than half of patients; about 30% of participants crossed this threshold. In our centre, 47.4% of participants consistently exceeded sputum eosinophils >3%, and 47.4% of patients crossed this threshold. Approximately 66.7% of participants had more than 50% alterations of serum total IgE, and 98.1% of participants continued to have IgE levels greater than 30 IU/mL. We used cluster analysis to classify variability and levels of FeNO and blood eosinophils and identified 4 patient clusters. Cluster 1 can be summarised as T2 severe asthma with low blood eosinophil levels and stability. Cluster 2 can be summarised as asthma with continuous increase and small fluctuations in various T2 inflammatory markers. Cluster 3 can be summarised as a non/low-T2 inflammatory phenotype. Cluster 4 can be summarised as a stable, moderate T2 inflammatory phenotype.

Conclusion

We identified the distributions and variable patterns of the T2 inflammatory markers currently used to guide asthma biotherapy in clinical practice. The longitudinal comprehensive multiple assessments of T2 inflammatory markers provide support for initiating biologic therapy patients with severe asthma whose biomarker levels vary.

Exploratory research on asthma exacerbation risk factors using the Japanese claims database and machine learning: A retrospective cohort study

OBJECTIVE

Analytical studies of risk factor assessment using machine learning have recently been reported. We performed an exploratory detection study of asthma exacerbation-related factors using health insurance claims data and machine learning to explore risk factors that have high generalizability and can be easily obtained in daily practice.

METHODS

A dataset of asthma patients during May 2014-April 2019 from Japanese health insurance claims database, MediScope® (DB) was used. Patient characteristics and disease information were extracted, and association with occurrence of asthma exacerbation was evaluated to comprehensively search for exacerbation risk factors. Asthma exacerbations were defined as the co-occurrence of emergency medical procedures, such as emergency transport and intravenous steroid injections, with asthma claims, which were recorded in the database.

RESULTS

In total, 5,844 (13.7%) subjects had exacerbations in 42,685 eligible cases from the DB. Information on approximately 3,300 diseases was subjected to a machine learning, and 25 variables were extracted as variable importance and targeted for risk assessment. As a result, sex, days without exacerbation from cohort entry date at look-back period, Charlson Comorbidity Index, allergic rhinitis, chronic sinusitis, acute airway disease (upper airway), acute airway disease (lower airways), Chronic obstructive pulmonary disease/chronic bronchitis, gastroesophageal reflux disease, and hypertension were significantly associated with exacerbation. Dyslipidemia and periodontitis were detected as associated factors of reduced exacerbation risk.

CONCLUSIONS

A comprehensive analysis of claims data using machine learning showed asthma exacerbation risk factors mostly consistent with those in previous studies. Further examination in other fields is warranted.

A territory-wide study on the factors associated with recurrent asthma exacerbations requiring hospitalization in Hong Kong

Background

The real‐world relationships between the demographic and clinical characteristics of asthma patients, their prehospitalization management and the frequency of hospitalization due to asthma exacerbation is poorly established.

Objective

To determine the risk factors of recurrent asthma exacerbations requiring hospitalizations and evaluate the standard of baseline asthma care.

Methods

A territory‐wide, multicentre retrospective study in Hong Kong was performed. Medical records of patients aged ≥18 years admitted to 11 acute general hospitals from January 1 to December 31, 2016 for asthma exacerbations were reviewed.

Results

There were 2280 patients with 3154 admissions (36.7% male, median age 66.0 [interquartile range: 48.0–81.0] years, 519 had ≥2 admissions). Among them, 1830 (80.3%) had at least one asthma‐associated comorbidity, 1060 (46.5%) and 885 (38.9%) of patients had Accident and Emergency Department (AED) attendance and hospitalization in the preceding year, respectively. Patients with advancing age (incidence rate ratio [IRR]: 1.003 for every year increment), a history of AED visits or hospitalization (IRR: 1.018 and 1.070 for every additional episode, respectively) for asthma exacerbation in the preceding year, the presence of neuropsychiatric (IRR: 1.142) and gastrointestinal (IRR: 1.154) comorbidities were risk factors for an increasing number of admissions for asthma exacerbation. For patients with ≥2 admissions, 17.1% were not prescribed inhaled corticosteroid and only 44.6% had spirometry checked before the index admission. Asthma phenotyping was often incomplete, as assessment of atopy (total serum immunoglobulin E level and senitization to aeroallergens) was only performed in 30 (5.8%) patients with ≥2 admissions.

Conclusions and Clinical Relevance

Improving asthma care, especially in elderly patients with a prior history of urgent healthcare utilization and comorbidities, may help reduce healthcare burden. Suboptimal management before the index admission was common in patients hospitalized for asthma exacerbations. Early identification of patients at risk and enhancement of baseline asthma management may help to prevent recurrent asthma exacerbation and subsequent hospitalization.