Time trend in the prevalence of adult asthma in Japan: findings from population-based surveys in Fujieda City in 1985, 1999, and 2006

Characterizing Fit-for-Purpose Real-World Data: An Assessment of a Mother-Infant Linkage in the Japan Medical Data Center Claims Database

Purpose

Observational postapproval safety studies are needed to inform medication safety during pregnancy. Real-world databases can be valuable for supporting such research, but fitness for regulatory purpose must first be vetted. Here, we demonstrate a fit-for-purpose assessment of the Japan Medical Data Center (JMDC) claims database for pregnancy safety regulatory decision-making.

Patients and Methods

The Duke-Margolis framework considers a database's fitness for regulatory purpose based on relevancy (capacity to answer the research question based on variable availability and a sufficiently sized, representative population) and quality (ability to validly answer the research question based on data completeness and accuracy). To assess these considerations, we examined descriptive characteristics of infants and pregnancies among females ages 12-55 years in the JMDC between January 2005 and March 2022.

Results

For relevancy, we determined that critical data fields (maternal medications, infant major congenital malformations, covariates) are available. Family identification codes permitted linkage of 385,295 total mother-infant pairs, 57% of which were continuously enrolled during pregnancy. The prevalence of specific congenital malformation subcategories and maternal medical conditions were representative of the general population, but preterm births were below expectations (3.6% versus 5.6%) in this population. For quality, our methods are expected to accurately identify the complete set of mothers and infants with a shared health insurance plan. However, validity of gestational age information was limited given the high proportion (60%) of missing live birth delivery codes coupled with suppression of infant birth dates and inaccessibility of disease codes with gestational week information.

Conclusion

The JMDC may be well suited for descriptive studies of pregnant people in Japan (eg, comorbidities, medication usage). More work is needed to identify a method to assign pregnancy onset and delivery dates so that in utero medication exposure windows can be defined more precisely as needed for many regulatory postapproval pregnancy safety studies.

Executive summary: Japanese guidelines for adult asthma (JGL) 2021

Asthma is characterized by chronic airway inflammation, variable airway narrowing, and sensory nerve irritation, which manifest as wheezing, dyspnea, chest tightness, and cough. Longstanding asthma may result in airway remodeling and become intractable. Despite the increased prevalence of asthma in adults, asthma-associated deaths have decreased in Japan (0.94 per 100,000 people in 2020). The goals of asthma treatment include the control of symptoms and reduction of future risks. A functional partnership between physicians and patients is indispensable for achieving these goals. Long-term management with medications and the elimination of triggers and risk factors are fundamental to asthma treatment. Asthma is managed via four steps of pharmacotherapy ("controllers"), ranging from mild to intensive treatments, depending on disease severity; each step involves daily administration of an inhaled corticosteroid, which varies from low to high dosage. Long-acting β₂ agonists, leukotriene receptor antagonists, sustained-release theophylline, and long-acting muscarinic antagonists are recommended as add-on drugs. Allergen immunotherapy is a new option that is employed as a controller treatment. Further, as of 2021, anti-IgE antibody, anti-IL-5 and anti-IL-5 receptor α-chain antibodies, and anti-IL-4 receptor α-chain antibodies are available for the treatment of severe asthma. Bronchial thermoplasty can be performed for asthma treatment, and its long-term efficacy has been reported. Algorithms for their usage have been revised. Comorbidities, such as allergic rhinitis, chronic rhinosinusitis, chronic obstructive pulmonary disease, and aspirin-exacerbated respiratory disease, should also be considered during the treatment of chronic asthma. Depending on the severity of episodes, inhaled short-acting β₂ agonists, systemic corticosteroids, short-acting muscarinic antagonists, oxygen therapy, and other approaches are used as needed ("relievers") during exacerbation.

Identification of asthma cases in Japan using health insurance claims data: Positive and negative predictive values of proposed discrimination criteria: A single-center study

BACKGROUND

Asthma cases have been increasingly investigated using claims data. However, the validity of defining asthma cases using health insurance claims in Japan is unclear. This study aims to assess the positive and negative predictive values of our proposed discrimination criteria for asthma.

METHODS

We developed discrimination criteria for asthma based on both the International Statistical Classification of Diseases and Related Health Problems (ICD)-10 disease codes for asthma and health insurance claims data for prescriptions and the treatment of asthma. Inclusion criteria were patients aged ≥16 years with at least one health insurance claim from April 2018 to March 2019 in all departments of our hospital. Physician-diagnosed asthma documented in the charts was used as the reference standard. Positive and negative predictive values of the discrimination criteria for physician-diagnosed asthma were estimated and compared with those estimated from discrimination criteria based solely on ICD-10 codes.

RESULTS

The new discrimination criteria had a high positive predictive value (PPV) of 86.0%, which was significantly higher than the PPV for the criteria defined solely by the ICD-10 codes (61.5%) (P < 0.01). The negative predictive values for both criteria were 100%. Allergic rhinitis and chronic cough were frequently misclassified as asthma using the discrimination criteria based solely on ICD-10 codes but were more likely to be appropriately classified using our proposed criteria.

CONCLUSIONS

Our proposed criteria adequately identified asthma subjects using health insurance claims data in Japan with a high PPV. Further studies are needed for external validation of these criteria.

Longitudinal changes in the prevalence of adult asthma: An epidemiological survey among Japanese salaried employees and their dependents using healthcare insurance claim from 1999 to 2019

BACKGROUND

Information on changes in asthma prevalence and the treatment status for asthma is used as basic information for taking medical and administrative measures against asthma. However, this information among adults is relatively limited.

METHODS

To elucidate changes in the prevalence of asthma and treatment status over time among Japanese adults, health insurance claim data from some health insurance societies covering salaried employees and their dependents were studied longitudinally. Claim data from FY1999 to 2007 were obtained from two health insurance societies, and data from FY 2011 to 2019 were obtained from three different health insurance societies, and changes in standardized asthma prevalence among subjects aged 20-59 years, proportion of asthma patients prescribed ICS, leukotriene receptor antagonist (LTRA), and LABA, and the mean number of acute asthma exacerbations per year were analyzed.

RESULTS

The prevalence of asthma increased from 1.6% in 1999 to 3.0% in 2007 and 2.9% in 2011 to 4.6% in 2019. Increased trends in asthma prevalence from 2011 to 2019 were more noticeable in subjects in their 50s than those in their 20s for both sexes. The number of emergency visits related to asthma was 1.5 per year in 1999, which decreased to 0.8 per year in 2019. The proportion of people prescribed all anti-asthma medications (ICS, LTRA, and LABA) increased over time.

CONCLUSIONS

The prevalence of adult asthma among Japanese salaried employees and their dependents has increased over the last 20 years, suggesting more attention should be paid to the prevention of this disease in adults.

Effectiveness of Switching Biologics for Severe Asthma Patients in Japan: A Single-Center Retrospective Study

BACKGROUND

In Japan, biologic therapy was initiated for patients with severe asthma in 2009. In recent years, four biologics with different mechanisms of action have become available in the clinical setting. However, the efficacy of switching between biologics remains uncertain.

METHODS

To elucidate the efficacy of switching between biologics, 97 patients were enrolled who had received any biologic therapy for severe asthma at Jikei University Hospital, Tokyo, Japan, from July 2009 to December 2020. We retrospectively examined the patient characteristics, biomarkers, pulmonary function test results, selected biologics, and efficacy.

RESULTS

Thirty-one males and 66 females received any biologics. The mean age was 53.3 years at the initiation of biologic therapy. Initially, 33, 41, 15 and eight patients received omalizumab, mepolizumab, benralizumab, and dupilumab, respectively. Among three representative indicators for biologics administration, the peripheral blood eosinophil count, serum IgE levels and fractional exhaled nitric oxide, 64% of the patients had two indicators, and 28% had three indicators. Thirty-four patients (35%) switched from the initial biologic to another, and the reasons for switching included persistent asthmatic symptoms (n=22), schedule of hospital visits (n=5), and other reasons. Thus, the treatment was effective in 11 patients after switching. In addition, two patients received combination therapy with different biologics. Eighteen patients (19%) interrupted treatment for various reasons. Regardless of whether the biologic was the initial therapy, the overall efficacy of the four biologics was 60% based on the global evaluation of treatment effectiveness.

CONCLUSION

Switching between biologics can be a promising option for severe asthma patients in whom treatment with an initial biologic is ineffective.

Japanese guidelines for adult asthma 2020

Bronchial asthma is characterized by chronic airway inflammation, which manifests clinically as variable airway narrowing (wheezes and dyspnea) and cough. Long-standing asthma may induce airway remodeling and become intractable. The prevalence of asthma has increased; however, the number of patients who die from it has decreased (1.3 per 100,000 patients in 2018). The goal of asthma treatment is to control symptoms and prevent future risks. A good partnership between physicians and patients is indispensable for effective treatment. Long-term management with therapeutic agents and the elimination of the triggers and risk factors of asthma are fundamental to its treatment. Asthma is managed by four steps of pharmacotherapy, ranging from mild to intensive treatments, depending on the severity of disease; each step includes an appropriate daily dose of an inhaled corticosteroid, which may vary from low to high. Long-acting β₂-agonists, leukotriene receptor antagonists, sustained-release theophylline, and long-acting muscarinic antagonists are recommended as add-on drugs, while anti-immunoglobulin E antibodies and other biologics, and oral steroids are reserved for very severe and persistent asthma related to allergic reactions. Bronchial thermoplasty has recently been developed for severe, persistent asthma, but its long-term efficacy is not known. Inhaled β₂-agonists, aminophylline, corticosteroids, adrenaline, oxygen therapy, and other approaches are used as needed during acute exacerbations, by selecting treatment steps for asthma based on the severity of the exacerbations. Allergic rhinitis, eosinophilic chronic rhinosinusitis, eosinophilic otitis, chronic obstructive pulmonary disease, aspirin-exacerbated respiratory disease, and pregnancy are also important conditions to be considered in asthma therapy.

Age-period-cohort analysis of asthma, allergic rhinitis, and atopic dermatitis prevalence in Japan

This study aims to analyze the trends in the Japanese prevalence of asthma, allergic rhinitis, and atopic dermatitis by using age–period–cohort (APC) analysis. Data regarding the prevalence of diseases from 1999 to 2017 were collected from Patient Survey in Japan. The data were divided according to age groups ranging from 0–4 years old up to 65–69 years old in 5-year increments. A cohort was defined for each age group of each year with a one-year shift, and cohorts born from 1930–1934 up to 2013–2017 were examined. We used Bayesian APC analysis to decompose the changes in prevalence into age, period, and cohort effects. Results show that the period effect for asthma began to increase in 2008, and those of allergic rhinitis and atopic dermatitis began to increase in 1999. The cohort effects for asthma and atopic dermatitis increased rapidly in cohorts born from approximately 1950 to 1980 and then decreased thereafter. Furthermore, the cohort effect for allergic rhinitis increased from cohorts born in approximately the late 1970s for men and in 1990 for women. The time points with increasing cohort effects for asthma and atopic dermatitis are consistent with the history of air pollution accompanied by rapid economic growth in Japan. The onset of the increased cohort effect for allergic rhinitis was also relatively consistent with the time point at which the mass scattering of pollen began.

Sale-based estimation of pharmaceutical concentrations and associated environmental risk in the Japanese wastewater system

Information on sales and emission of selected pharmaceuticals were used to predict their concentrations in Japanese wastewater influent through a >300 of pharmaceuticals data sink. A combined wastewater-based epidemiology and environmental risk analysis follow was established. By comparing predicted environmental concentrations (PECs) of pharmaceuticals in wastewater influent against measured environmental concentrations (MECs) reported in previous studies, it was found that the model gave accurate results for 17 pharmaceuticals (0.5 < PEC/MEC < 2), and acceptable results for 32 out of 40 pharmaceuticals (0.1 < PEC/MEC < 10). Although the majority of pharmaceuticals considered in the model were antibiotics and analgesics, pranlukast, a receptor antagonist, was predicted to have the highest concentration in wastewater influent. With regard to the composition of wastewater effluent, the Estimation Program Interface (EPI) suite was used to predict pharmaceutical removal through activated sludge treatment. Although the performance of the EPI suite was variable in terms of accurate prediction of the removal of different pharmaceuticals, it could be an efficient tool in practice for predicting removal under extreme scenarios. By using the EPI suite with input data on PEC in the wastewater influent, the PEC values of pharmaceuticals in wastewater effluent were predicted. The concentrations of 26 pharmaceuticals were relatively high (>1 μg/L), and the PECs of 6 pharmaceuticals were extremely high (>10 μg/L) in wastewater effluent, which could be attributed to their high usage rates by consumers and poor removal rates in wastewater treatment plants (WWTPs). Furthermore, environmental risk assessment (ERA) was carried out by calculating the ratio of predicted no effect concentration (PNEC) to PEC of different pharmaceuticals, and it was found that 9 pharmaceuticals were likely to have high toxicity, and 54 pharmaceuticals were likely to have potential toxicity. It is recommended that this is further investigated in detail. The priority screening and environmental risk assessment results on pharmaceuticals can provide reliable basis for policy-making and environmental management.

Efficacy of mepolizumab for patients with severe asthma and eosinophilic chronic rhinosinusitis

Background

Several major randomized control studies have demonstrated that mepolizumab, an anti-IL-5 monoclonal antibody, is effective for patients with severe eosinophilic asthma who show exacerbation or require systemic corticosteroid maintenance therapy. However, the predictive factors of the response to mepolizumab other than blood eosinophil count are unclear in clinical practice.

Objective

To elucidate the predictive factors of the response to mepolizumab for patients with severe eosinophilic asthma.

Methods

From July 2016 to December 2017, 28 patients with severe asthma received mepolizumab in our hospital. To determine the predictive factors, we retrospectively evaluated patient characteristics, comorbidities, biomarkers, pulmonary function, maintenance dose of systemic corticosteroids and number of exacerbations.

Results

The response rate to mepolizumab treatment was 70% (19/27; one pregnant woman was excluded from analysis). Compared with 11 patients without eosinophilic chronic rhinosinusitis (ECRS), 16 patients with ECRS showed significantly improved systemic corticosteroid-sparing effects [− 71.3 ± 37.0% vs − 10.7 ± 20.1%, P = 0.006], change from baseline FeNO [− 19 ± 57 (%) vs 30 ± 77 (%), P = 0.023] and symptoms [14 patients (88%) vs five patients (45%), P = 0.033]. ECRS was identified as a predictive factor of the response to mepolizumab in a multivariate logistic regression analysis [odds ratio = 22.5, 95% CI (1.5–336), P = 0.024]. Of the eight patients previously administered omalizumab, five responded to mepolizumab. Staphylococcus aureus enterotoxin B IgE results were negative in 80% of responders (P = 0.14).

Conclusion

Both groups showed improved symptom scores and a decreased number of exacerbations. Mepolizumab substantially improved the clinical variables of patients with eosinophilic asthma complicated with ECRS.

Association between Household Food Insecurity and Asthma in Korean Adults

Household food insecurity has been associated with noncommunicable diseases. The aim of this study was to investigate the association between household food insecurity and asthma in Korean adults. Household food security statuses were classified into three groups: Food-secure household, food-insecure household without hunger, and food-insecure household with hunger. The odds ratios and 95% confidence intervals for the presence of asthma according to household food security status were calculated using multiple logistic regression analyses after adjusting for confounding factors. A total of 14,770 participants were included in the analysis. The prevalence of asthma was 2.6% in those with a secure food status, 3.2% in those with an insecure food status without hunger, and 7.6% in those with an insecure food status with hunger (p < 0.001). Compared with that in participants with a household food secure status, the odds ratios (95% confidence intervals) for asthma were 1.12 (0.73–1.73) in those with a food-insecure household without hunger status and 2.44 (1.33–4.46) in those with a food-insecure household with hunger status after additionally adjusting for confounding factors. We found that household food insecurity with hunger was significantly associated with asthma prevalence in Korean adults. Implementation of household food security screening and public health intervention could be helpful to prevent and reduce asthma in adults.

Trends in the prevalence of airflow limitation in a general Japanese population: two serial cross-sectional surveys from the Hisayama Study

OBJECTIVES

Chronic obstructive airway disease, which is characterised by airflow limitation, is a major burden on public health. Reductions in environmental pollution in the atmosphere and workplace and a decline in the prevalence of smoking over recent decades may have affected the prevalence of airflow limitation in Japan. The present epidemiological study aimed to evaluate trends in the prevalence of airflow limitation and in the influence of risk factors on airflow limitation in a Japanese community.

DESIGN

Two serial cross-sectional surveys.

SETTING

Data from the Hisayama Study, a population-based prospective study that has been longitudinally conducted since 1961.

PARTICIPANTS

A total of 1842 and 3033 residents aged ≥40 years with proper spirometric measurements participated in the 1967 and 2012 surveys, respectively.

MAIN OUTCOME MEASURES

Airflow limitation was defined as forced expiratory volume in 1 s/forced vital capacity <70% by spirometry. For each survey, the age-adjusted prevalence of airflow limitation was evaluated by sex. ORs and population attributable fractions of risk factors on the presence of airflow limitation were compared between surveys.

RESULTS

The age-standardised prevalence of airflow limitation decreased from 1967 to 2012 in both sexes (from 26.3% to 16.1% in men and from 19.8% to 10.5% in women). Smoking was significantly associated with higher likelihood of airflow limitation in both surveys, although the magnitude of its influence was greater in 2012 than in 1967 (the multivariable-adjusted OR was 1.63 (95% CI 1.19 to 2.24) in 1967 and 2.26 (95% CI 1.72 to 2.99) in 2012; p=0.007 for heterogeneity). Accordingly, the population attributable fraction of smoking on airflow limitation was 33.5% in 2012, which was 1.5-fold higher than that in 1967 (21.1%).

CONCLUSIONS

The prevalence of airflow limitation was decreased over 45 years in Japan, but the influence of smoking on airflow limitation increased with time.

Safety profile of the SQ house dust mite sublingual immunotherapy-tablet in Japanese adult patients with house dust mite-induced allergic asthma: a randomized, double-blind, placebo-controlled phase I study

Objective: The SQ house dust mite (HDM) sublingual immunotherapy (SLIT)-tablet has demonstrated effective treatment of HDM-induced allergic asthma in patients 18 years or older in European trials. This study investigated its safety and immunology profile in Japanese adult patients with mild-to-moderate HDM-induced allergic asthma. Methods: In this randomized, double-blind, placebo-controlled study, 48 Japanese patients were randomly assigned to a daily treatment of SQ HDM SLIT-tablet or placebo (3:1) for 14 d with or without an up-dosing regimen. Active groups comprised 5000, 10,000 or 20,000 Japanese Allergy Unit (JAU) for 14 d, and the up-dosing group comprised 5,000 JAU in day 1-3, 10,000 JAU in day 4-7 and 20,000 JAU in day 8-14. Results: No marked differences were observed in the incidence rate of adverse events (AEs) and their severity among active groups. The five most common investigational medicinal product (IMP)-related AEs were local events at the application site observed within 30 min after the intake of the SQ HDM SLIT-tablet. Although most events recovered within 1 h, mouth edema indicated a different profile of duration with more than 25% of the events lasting for more than 1 h. Conclusions: The SQ HDM SLIT-tablet of up to 20,000 JAU was well tolerated, and safety profile was acceptable for Japanese subjects with HDM-induced allergic asthma.

Patients with Asthma Prescribed Once-Daily Fluticasone Furoate/Vilanterol or Twice-Daily Fluticasone Propionate/Salmeterol as Maintenance Treatment: Analysis from a Claims Database

Introduction

There is a paucity of data describing prescribing patterns and adherence to therapy of inhaled corticosteroids (ICS) in combination with long-acting β₂-agonists (LABA) in the Japanese population in clinical practice.

Methods

This was a non-interventional, retrospective, cohort study of patients who were prescribed medication for asthma, using data from the Japan Medical Data Center Claims Database. Data from patients aged ≥ 15 years with a prescription of asthma drugs between December 2014 and October 2015 (Day 0, the index date when asthma medication was initiated) were analysed in 12-month pre-index and post-index periods. Part 1 focused on baseline characteristics and epidemiological outcomes in the pre- and post-index period in the overall asthma population, whereas comparing medication adherence [number of prescribed days per year and proportion of days covered (PDC)] between ICS/LABA-naïve patients treated with once-daily fluticasone furoate/vilanterol (FF/VI) and twice-daily fluticasone propionate/salmeterol (FP/SAL) was the primary endpoint in Part 2.

Results

Of the available patient data (N = 2,953,652), 28,699 patients were identified as having asthma. ICS/LABA was the main asthma treatment prescribed; 11,167 (38.9%) patients were continuous ICS/LABA users. In ICS/LABA-naïve asthma patients, treatment with once-daily FF/VI was associated with higher medication adherence compared with twice-daily FP/SAL; mean [standard deviation (SD)] number of prescribed days per year was 97.8 (115.9) for FF/VI versus 80.5 (92.7) for FP/SAL (p = 0.04), mean (SD) PDC was 26.7% (31.5) for FF/VI versus 21.9% (24.8) for FP/SAL (p = 0.04). FF/VI was also associated with a lower rate of treatment discontinuation and no difference in use of short-acting beta₂-agonists or oral corticosteroids compared with FP/SAL.

Conclusions

ICS/LABA was the major prescribed asthma treatment in Japan. Medication adherence was greater with FF/VI, which may indicate that patients are more likely to adhere to once-daily FF/VI versus twice-daily FP/SAL.

Funding

This study was funded by GSK (study sponsor).

Study Registration

GSK Study No. 207264, GSK Study Register site: https://www.gsk-clinicalstudyregister.com/search/?search_terms=207264.

Electronic supplementary material

The online version of this article (10.1007/s41030-018-0084-4) contains supplementary material, which is available to authorized users.

The prevalence, burden and risk factors associated with bronchial asthma in commonwealth of independent states countries (Ukraine, Kazakhstan and Azerbaijan): results of the CORE study

Background

In the Commonwealth of Independent States (CIS) countries epidemiology of Bronchial Asthma (BA) is poorly characterized. The objective of this analysis is to present the prevalence, burden and risk factors associated with BA in the CIS countries as part of the CORE study (Chronic Obstructive REspiratory diseases).

Methods

A total of 2842 adults (≥18 years) were recruited (964 in Kiev, Ukraine, 945 in Almaty, Kazakhstan, and 933 in Baku, Azerbaijan) in 2013–2015 during household visits. A two-step cluster random sampling strategy was used. All respondents were interviewed about respiratory symptoms, smoking, medical history. Two definitions were used: (i) “doctor diagnosed asthma” when the respondent reported that he/she had ever been diagnosed with BA by a doctor, (ii) “wheezing symptoms” (when the respondent reported wheezing at the ATS Respiratory Symptoms Questionnaire during the study) using GINA (2012) recommendations. Chi-square tests were used to assess differences in proportions. Binary logistic regression was used to estimate odds ratios (OR) and 95% CI for association between risk factors and BA.

Results

Prevalence of “doctor diagnosed asthma” was 12.5, 19.0 and 26.8 per 1000 persons, and prevalence of “wheezing symptoms” was 74.4, 254.8 and 123.4 per 1000 in Ukraine, Kazakhstan, and Azerbaijan, respectively. Statistically significant relationship with “wheezing symptoms” was shown for smoking (OR 1.99 (CI 1.22–3.27) in Ukraine, 2.08 (CI 1.54–2.81) in Kazakhstan, 8.01 (CI 5.24–12.24) in Azerbaijan); overweight/obesity (OR: 1.66 (CI 1.02–2.72); 1.94 (CI 1.44–2.62); 1.77 (CI 1.18–2.68), respectively) and dusty work (OR: 3.29 (CI 1.57–6.89); 1.68 (CI 1.18–2.39); 2.36 (CI 1.56–3.59), respectively), and for tuberculosis in Azerbaijan (OR: 10.11 (CI 3.44–29.69)). Co-morbidities like hypertension, cardiovascular diseases, abnormal blood lipids and a history of pneumonia occurred significantly (p < 0.05) more frequently in respondents with BA compared to those without BA across all participating countries.

Conclusion

In CIS countries (Ukraine, Kazakhstan and Azerbaijan) the prevalence of doctor diagnosed asthma was significantly lower compared to prevalence of wheezing symptoms underlining that BA is likely to be underreported in these countries. The information provided in this paper will be helpful for healthcare policy makers in CIS countries to instruct BA management strategies and to allocate healthcare resources accordingly.

The Effect of Hidden Female Smoking on the Association between Smoking and Asthma

BACKGROUND

The association between smoking and asthma remains controversial. In our previous study, we were not able to show an association between asthma and smoking in Korean adults. One Korean study demonstrated underreporting of smoking history by female adults. The aim of the present study was to investigate the effects of hidden female smoking on the association between asthma and smoking in Korean adults.

METHODS

Data were acquired from 23,483 men and women aged ≥19 years who participated in the Korean National Health and Nutrition Examination Surveys (KNHANES).

RESULTS

The prevalence of asthma was 1.5%, the self-reported smoking prevalence was 32.4%, and the cotinine-verified smoking prevalence was 30.3%. Of the male cotinine-verified smokers, 6.4% were self-reported nonsmokers (2.7% never smokers and 3.7% ex-smokers), whereas 48.8% of the female cotinine-verified smokers were self-reported nonsmokers (43.2% never smokers and 5.6% ex-smokers). In males, the adjusted odds ratio of the association between smoking and asthma was 0.738 (confidence interval, CI: 0.393-1.173) in self-reported and 0.767 (CI: 0.515-1.143) in cotinine-verified smoking; in females, the adjusted odds ratio was 1.945 (CI: 1.348-2.805) in self-reported and 1.531 (CI: 1.076-2.179) in cotinine-verified smoking.

CONCLUSIONS

Our study showed smoking was associated with asthma in females but not in males.

Aqueous and organic extract of PM2.5 collected in different seasons and cities of Japan differently affect respiratory and immune systems

Particulate matter with diameters <2.5 μm (i.e., PM_2.5) has multiple natural and anthropological sources. The association between PM_2.5 and the exacerbation of respiratory allergy and asthma has been well studied, but the components of PM_2.5 that are responsible for allergies have not yet been determined. Here, we elucidated the effects of aqueous and organic extract of PM_2.5 collected during four seasons in November 2014-December 2015 in two cities (Kawasaki, an industrial area and Fukuoka, an urban area affected by transboundary pollution matter) of Japan on respiratory health. Ambient PM_2.5 was collected by high-volume air samplers and extracted into water soluble and lipid soluble components. Human airway epithelial cells, murine bone marrow-derived antigen-presenting cells (APC) and splenocytes were exposed to PM_2.5 extracts. We measured the cell viability and release of interleukin (IL)-6 and IL-8 from airway epithelial cells, the DEC205 and CD86 expressions on APCs and cell proliferation, and TCR and CD19 expression on splenocytes. The water-soluble or aqueous extracts, especially those from Kawasaki in fall, had a greater cytotoxic effect than the lipid-soluble or organic extracts in airway epithelial cells, but they caused almost no pro-inflammatory response. Extract of fall, especially the aqueous extract from Fukuoka, increased the DEC205 and CD86 expressions on APC. Moreover, aqueous extracts of fall, summer, and spring from Fukuoka significantly increased proliferation of splenocytes. Organic extract of spring and summer from Kawasaki significantly elevated the TCR expression, and organic extract of summer from Kawasaki decreased the CD19 expression. These results suggest that PM_2.5 extract samples are responsible for cytotoxicity in airway epithelial cells and for activating APCs and T-cells, which can contribute to the exacerbation of respiratory diseases such as asthma. These effects can differ by PM_2.5 components, collection areas and seasons.

Efficacy and safety of benralizumab in Japanese patients with severe, uncontrolled eosinophilic asthma

BACKGROUND

In the Phase III CALIMA trial, benralizumab significantly reduced asthma exacerbations, increased lung function, and alleviated symptoms for patients with severe, uncontrolled eosinophilic asthma. The aim of this subgroup analysis was to evaluate the efficacy and safety of benralizumab for Japanese patients in the CALIMA trial.

METHODS

CALIMA was a randomised, controlled trial of 1306 patients (aged 12-75 years; registered at ClinicalTrials.gov: NCT01914757) with severe asthma uncontrolled by medium- to high-dosage inhaled corticosteroids and long-acting β₂-agonists (ICS/LABA). Patients received 56 weeks' benralizumab 30 mg either every 4 weeks (Q4W) or every 8 weeks (Q8W; first three doses Q4W), or placebo Q4W. The primary analysis population was patients receiving high-dosage ICS/LABA with blood eosinophils ≥300 cells/μL. This subgroup analysis covered Japanese patients from this group.

RESULTS

Of 83 patients randomised in Japan, 46 were receiving high-dosage ICS/LABA and had blood eosinophils ≥300 cells/μL. Compared with placebo, benralizumab reduced the annual rate of asthma exacerbations by 66% (Q4W; rate ratio 0.34, 95% CI, 0.11-0.99) and 83% (Q8W; rate ratio 0.17, 95% CI, 0.05-0.60); increased prebronchodilator FEV₁ by 0.334 L (Q4W; 95% CI, 0.020-0.647) and 0.198 L (Q8W; 95% CI, -0.118 to 0.514); and decreased total asthma symptom score by 0.17 (Q4W; 95% CI, -0.82 to 0.48) and 0.24 (Q8W; 95% CI, -0.87 to 0.40). Percentages of adverse events were consistent with the overall CALIMA group.

CONCLUSIONS

Benralizumab reduced annual asthma exacerbations and symptoms, increased lung function, and was well-tolerated by Japanese patients with severe, uncontrolled eosinophilic asthma.

Japanese guidelines for adult asthma 2017

Adult bronchial asthma is characterized by chronic airway inflammation, and presents clinically with variable airway narrowing (wheezes and dyspnea) and cough. Long-standing asthma induces airway remodeling, leading to intractable asthma. The number of patients with asthma has increased; however, the number of patients who die of asthma has decreased (1.2 per 100,000 patients in 2015). The goal of asthma treatment is to enable patients with asthma to attain normal pulmonary function and lead a normal life, without any symptoms. A good relationship between physicians and patients is indispensable for appropriate treatment. Long-term management by therapeutic agents and elimination of the causes and risk factors of asthma are fundamental to its treatment. Four steps in pharmacotherapy differentiate between mild and intensive treatments; each step includes an appropriate daily dose of an inhaled corticosteroid, varying from low to high levels. Long-acting β₂-agonists, leukotriene receptor antagonists, sustained-release theophylline, and long-acting muscarinic antagonist are recommended as add-on drugs, while anti-immunoglobulin E antibody and oral steroids are considered for the most severe and persistent asthma related to allergic reactions. Bronchial thermoplasty has recently been developed for severe, persistent asthma, but its long-term efficacy is not known. Inhaled β₂-agonists, aminophylline, corticosteroids, adrenaline, oxygen therapy, and other approaches are used as needed during acute exacerbations, by choosing treatment steps for asthma in accordance with the severity of exacerbations. Allergic rhinitis, eosinophilic chronic rhinosinusitis, eosinophilic otitis, chronic obstructive pulmonary disease, aspirin-induced asthma, and pregnancy are also important issues that need to be considered in asthma therapy.

Mouth breathing, another risk factor for asthma: the Nagahama Study

BACKGROUND

Allergic rhinitis, a known risk factor for asthma onset, often accompanies mouth breathing. Mouth breathing may bypass the protective function of the nose and is anecdotally considered to increase asthma morbidity. However, there is no epidemiological evidence that mouth breathing is independently associated with asthma morbidity and sensitization to allergens. In this study, we aimed to clarify the association between mouth breathing and asthma morbidity and allergic/eosinophilic inflammation, while considering the effect of allergic rhinitis.

METHODS

This community-based cohort study, the Nagahama Study, contained a self-reporting questionnaire on mouth breathing and medical history, blood tests, and pulmonary function testing. We enrolled 9804 general citizens of Nagahama City in the Shiga Prefecture, Japan.

RESULTS

Mouth breathing was reported by 17% of the population and was independently associated with asthma morbidity. The odds ratio for asthma morbidity was 1.85 (95% CI, 1.27-2.62) and 2.20 (95% CI, 1.72-2.80) in subjects with mouth breathing alone and allergic rhinitis alone, which additively increased to 4.09 (95% CI, 3.01-5.52) when mouth breathing and allergic rhinitis coexisted. Mouth breathing in nonasthmatics was a risk for house dust mite sensitization, higher blood eosinophil counts, and lower pulmonary function after adjusting for allergic rhinitis.

CONCLUSION

Mouth breathing may increase asthma morbidity, potentially through increased sensitization to inhaled allergens, which highlights the risk of mouth-bypass breathing in the 'one airway, one disease' concept. The risk of mouth breathing should be well recognized in subjects with allergic rhinitis and in the general population.

Allergies are still on the rise? A 6-year nationwide population-based study in Korea

BACKGROUND

Some western countries recently have shown a slowdown in the incidence of allergic diseases after worldwide increasing trends, but there are few data from Asian populations concerning changing trend of allergic diseases. We evaluated the recent trends in the prevalence of asthma and other allergic diseases in Korea.

METHODS

From the database of Korean National Health Insurance, a nationwide diagnostic data from 2009 to 2014 were extracted and the national prevalence was analyzed.

RESULTS

The prevalence per 1000 people of atopic dermatitis, allergic rhinitis, and asthma in 2014 was 19.0, 133.1, and 36.3, respectively. The prevalence of three diseases was highest in the age group under 10 as, 95.0, 384.1, and 132.1 per 1000 people, while the prevalence in the over-10-year-group was only 11.6, 109.5, and 27.3, respectively. The prevalence of atopic dermatitis and allergic rhinitis gradually decreased with older age, but the prevalence of asthma showed a re-increasing pattern from the age group 30-39 and reached another peak for the age group 70-79. During the study period, the prevalence of asthma and atopic dermatitis showed decreasing tendency. In contrast, the prevalence of allergic rhinitis steadily increased until 2013, especially in the age group under 10.

CONCLUSIONS

The national prevalence of atopic dermatitis, and asthma did not show noticeable increase any more in Korea. However, the prevalence of allergic rhinitis still on the rise until recently, especially in the age group under 10. This is the first report in Asia suggesting a slowdown of the incidence of allergic diseases.

Respiratory symptoms/diseases prevalence is still increasing: a 25-yr population study

BACKGROUND

Few epidemiological surveys on general population samples estimated changes in prevalence of respiratory symptoms/diseases over a long time interval; our study aims to quantify the temporal changes in the prevalence rates of asthma, allergic rhinitis and Chronic Obstructive Pulmonary Disease (COPD) after 25 years from baseline.

METHODS

A general population sample participated in 3 cross-sectional surveys carried out in Central Italy (Pisa) in 1985-88 (n = 3865), 1991-93 (n = 2841), 2009-11 (n = 1620). 2276 (47%) subjects participated in at least 1 survey, 1723 (35.5%) in at least 2 surveys and 849 (17.5%) in all the 3 surveys. All subjects filled in a standardized questionnaire about health status and risk factors; a sub-sample performed spirometry. Chi-square test was used to compare adjusted prevalence rates of respiratory symptoms/diseases and descriptive characteristics among the surveys. Generalised estimating equations (GEE) were used to analyze the association between respiratory symptoms/diseases and risk factors.

RESULTS

There was an increasing trend in prevalence rates of all respiratory symptoms/diseases throughout the surveys: current asthma attacks (1st-3rd survey prevalence: 3.4-7.2%), allergic rhinitis (16.2-37.4%), usual phlegm (8.7-19.5%) and COPD (2.1-6.8%) more than doubled. The GEE model confirmed these increasing trends, indicating higher risk of having respiratory symptoms/diseases in the second and third surveys.

CONCLUSIONS

While asthma and allergic rhinitis increasing trends were confirmed, with respect to other international studies, also a COPD increasing prevalence rates was shown.

Depression's influence on the Asthma Control Test, Japanese version

BACKGROUND

Depression has been linked to poorer asthma control in asthmatic patients. Although the Japanese version of the Asthma Control Test (ACT-J) is frequently used as a simple, practical evaluation tool in clinical care settings in Japan, knowledge regarding its efficacy for assessing asthma control in asthmatic patients with depression is limited. Thus, we retrospectively investigated cut-off values of the ACT-J for well-controlled asthma, and explored depression's influence on the test with a questionnaire survey.

METHODS

Data were analyzed on 1,962 adult asthmatic patients who had completed both the ACT-J and the Japanese version of the Patient Health Questionnaire-9 (J-PHQ-9) in 2008 questionnaire survey conducted by the Niigata Asthma Treatment Study Group. Patients were classified into low (LD: J-PHQ-9 score of 0-4) or high depression (HD: J-PHQ-9 score of 5-27) groups. In both groups, the efficacy of the ACT-J was confirmed. We then compared the optimal cut-off points for uncontrolled asthma in both groups by performing a receiver operating characteristic (ROC) analysis, using the original classification referred to the GINA classification as the "true" classification.

RESULTS

Cronbach's alpha in the LD and HD group was 0.808 and 0.740 respectively. In both groups, the sub-group with existence of work absenteeism or frequent attacks during the previous 12 months scored lower on the ACT-J. The area under the curve and optimal cut-off point for patients with LD and HD were 0.821 and 0.846, and 23 and 20 respectively.

CONCLUSIONS

The efficacy of the ACT-J was confirmed in depressive patients with asthma. Because asthma control as evaluated with the ACT-J can be worse than actual control under depressive states, physicians should also pay attention to a patient's depressive state at evaluation. Further investigations focus on the association between the ACT-J and depression are required.

Association between kimchi intake and asthma in Korean adults: the fourth and fifth Korea National Health and Nutrition Examination Survey (2007-2011)

This study was performed to investigate the relationship between dietary factors and asthma in a representative population-based sample of 19,659 men and women, aged 19-64 years, using data from the fourth and fifth Korean National Health and Nutrition Examination Survey (KNHANES), 2007-2011. The presence of asthma was based on self-reported physician diagnosis of asthma in the Health Interview Surveys. Food intake was estimated by trained interviewers using a 24-h recall method. The prevalence of asthma in Korean adults was 2.4%. Adults with asthma consumed fewer amounts of kimchi (P=.0444) and fish (P=.0175) but had a higher cereal intake than those without asthma (P=.0056). Multiple logistic regression analysis after controlling for confounding factors showed a significant inverse relationship between kimchi consumption and the prevalence of asthma [odds ratio (95% confidence interval) for subjects consuming 1 to <2 servings (40-79.9 g), 2 to <3 servings (80-119.9 g), and ≥3 servings (≥120 g), relative to those consuming <1 serving (<40 g): 0.726 (0.534-0.987), 0.506 (0.348-0.736), and 0.678 (0.502-0.916), respectively; P for trend=0.0131]. These results warrant future studies to explore the mechanisms responsible for the association between kimchi consumption and asthma.

Operational definitions of asthma in recent epidemiological studies are inconsistent

OBJECTIVE

The best combination of questions to define asthma in epidemiological asthma studies is not known. We summarized the operational definitions of asthma used in prevalence studies and empirically assess how asthma prevalence estimates vary depending on the definition used.

METHODS

We searched the Thomson Reuters ISI Web of knowledge and included (1) cross-sectional studies (2) on asthma prevalence (3) conducted in the general population and (4) containing an explicit definition of asthma. The search was limited to the 100 most-cited papers or published since January 2010. For each paper, we recorded the asthma definition used and other variables. Then we applied the definitions to the data of the Portuguese National Asthma survey (INAsma) and of the 2005-2006 National Health and Nutrition Examination Survey (NHANES) computing asthma prevalence estimates for the different definitions.

RESULTS

Of 1738 papers retrieved, 117 were included for analysis. Lifetime asthma, diagnosed asthma and current asthma were defined in 8, 12 and 29 different ways, respectively. By applying definitions of current asthma on INAsma and NHANES data, the prevalence ranged between 5.3%-24.4% and 1.1%-17.2%, respectively.

CONCLUSIONS

There is considerable heterogeneity in the definitions of asthma used in epidemiological studies leading to highly variable estimates of asthma prevalence. Studies to inform a standardized operational definition are needed. Meanwhile, we propose a set of questions to be reported when defining asthma in epidemiological studies.

The Prevalence of Asthma in an Adult Population in Khorramabad, Iran

OBJECTIVE

Asthma is one of the most common respiratory disorders. There have not been any studies assessing the prevalence rate for asthma based on spirometry in an adult population in the west of Iran. The aim of this study was to assess the prevalence of asthma in an adult population in Khorramabad, in the west of Iran.

METHODS

This prospective cross-sectional study was done on adult residents in Khorramabad between 2009 and 2010. The samples were selected by cluster and systematic sampling methods. The interviewers went to the selected homes and evaluated the samples by the standard questionnaire of the European Community Respiratory Health Survey. The individuals who were susceptible to asthma were evaluated using a hand-held spirometer (ZAN 100, Obertulba, Germany). Also, in the patients whose first spirometry had been normal, a more than 10% reduction in forced expiratory volume in one second (FEV1) after the exercise and more than 12% rise in FEV1 after the salbutamol spray inhalation was considered as having asthma. Finally, the data were summarized using means and percentages.

RESULTS

Eight hundred and fifty-seven adults were evaluated by the questionnaire and 450 were referred to the pulmonologist office. The frequency of spirometry-diagnosed asthma in the adult residents of Khorramabad was 9.45%.

CONCLUSION

The prevalence of asthma in Khorramabad in our study was more than in similar studies in Iran and other countries. Doing analytical studies on the prevalence of asthma and its risk factors is recommended.

Epidemiology of adult asthma in Asia: toward a better understanding

Asia is the world's most dynamic area. Asthma is a major chronic disease in Asia, like other continents. However, unlike childhood asthma, the epidemiological burden of asthma in Asian adults has been unclear. Here we reviewed the currently available literatures on the epidemiology of adult asthma in the Asian community populations. Adult asthma prevalence was generally lower in Asian than in Europe, but the increasing trends suggested the disease burden to rise in the near future. However, for better understanding, it may be essential to prepare for the Asian multinational network for the standardization and collaboration of research.

Prevalence of asthma and allergic rhinitis among adult population in Ulaanbaatar, Mongolia

Background

Mongolia is changing lifestyle, unhealthy habits, increase of air pollution, increasing life expectancy have led to an up rise of chronic respiratory diseases. Over 10 years ago, the prevalence of asthma and allergic rhinoconjunctivitis in Mongolia were in the lower range reported from previous studies.

Objective

The main aim of the survey is to know the prevalence of asthma and allergic rhinitis among adult population of Ulaanbaatar city, Mongolia and their risk factors.

Methods

Total of approximately 1,200 adults aged 20 years and over were planned to be randomly selected. The questionnaire was developed on the basis of WHO Protocol for Assessment of Prevalence of Major Respiratory Diseases and modified by local risk factors assessment and by other international survey approach including Global Initiative for Asthma and European Community Respiratory Health Survey.

Results

Prevalence of current wheezer in all age group was 15.7% (95% CI: 14.7-16.8). Age and sex segregated distribution of current wheezer were defined among male and female and prevalence was 14.5% (95% CI: 13.3-16.2) in male and female 16.6% (95% CI: 15.2-18.3) respectively. Prevalence of diagnosed asthma among adults was 4.7% (95% CI: 4.3-5.6) in all age group, 3% (95% CI: 2.4-3.7) in male and 6.8% (95% CI: 5.8-7.9) in female. Prevalence of rhinoconjunctivitis was 14.6% in all age group. 28.4% out of subjects with allergic rhinitis has current asthma, while 11.6% of subjects without allergic rhinitis has asthma (p < 0.01).

Conclusion

The prevalence of asthma increased for one decade in Ulaanbaatar. Prevalence of diagnosed asthma is approximately 5% and current wheezer is approximately 15% in adults of population, which is close to other Asia and European countries. Allergic rhinitis is a risk factor for asthma.

The Asthma Control Test, Japanese version (ACT-J) as a predictor of Global Initiative for Asthma (GINA) guideline-defined asthma control: analysis of a questionnaire-based survey

BACKGROUND

The 2006 Global Initiative for Asthma (GINA 2006) guidelines emphasize the importance of evaluating the control rather than the severity of asthma. The Asthma Control Test (ACT) is well known to be an excellent tool for evaluating asthma control in the clinical setting. This study aimed to evaluate the ACT, Japanese version (ACT-J) as a predictor of asthma control as defined by the GINA 2006 guidelines in actual clinical practice.

METHODS

A cross-sectional analysis comparing the ACT-J score and GINA classification of asthma control among 419 patients of primary care physicians and specialists was performed using the data from a 2010 questionnaire-based survey conducted by the Niigata Asthma Treatment Study Group.

RESULTS

The optimal cut-off point of the ACT-J score for predicting GINA-defined asthma control was 23, with ACT-J scores of ≥23 and ≤22 predicting controlled and uncontrolled asthma with area under the receiver operating characteristics curve values of 0.76 [95% confidence interval (CI): 0.72-0.81] and 0.93 [95% CI: 0.90-0.97], respectively.

CONCLUSIONS

ACT scores of ≥23 and ≤22 are useful for identifying patients with controlled and uncontrolled asthma, respectively, as defined by GINA 2006, and the latter is more strongly predictive than the former. The reason for the higher cut-off point of the ACT-J relative to other versions of the ACT is unclear and warrants further investigation.

Increased prevalence of self-reported asthma among Korean adults: an analysis of KNHANES I and IV data

BACKGROUND

Asthma is one of the most common chronic conditions. Knowing the longitudinal trends of prevalence is important in developing health service planning and in assessing the impact of the disease. However, there have been no studies that examined current asthma prevalence trends in Korea through the analysis of nationwide surveys.

METHODS

Data were acquired from patients aged 20-59 years who participated in the First Korean National Health and Nutritional Examination Surveys (KNHANES), which was conducted in 1998, and in the second year of the Fourth KNHANES, which was conducted in 2008. To estimate the prevalence of asthma with age and gender standardization, we used data from the Population and Housing Census, which was conducted by Statistics Korea in 2005.

RESULTS

The prevalence of physician-diagnosed asthma increased from 1998 to 2008 (1998: 0.7 %, 2008: 2.0 %). The prevalence of asthma medication usage also increased from 1998 to 2008 (1998: 0.3 %, 2008: 0.7 %); however, the prevalence of wheezing decreased between 1998 and 2008 (1998: 13.7 %, 2008: 6.3 %). A similar trend was observed after estimating the prevalence of asthma with age and gender standardization. Allergic rhinitis might be the reason for the increased prevalence of physician-diagnosed asthma, while the observed decrease in wheezing may be related to the decrease in smoking or the increase in the use of asthma medication.

CONCLUSIONS

The present study showed that the prevalence of both self-reported physician-diagnosed asthma and asthma medication usage increased from 1998 to 2008 in Korea, despite a possible changing pattern of diagnosing asthma.

Efficacy of using the Japanese version of the asthma control test for determing the level of asthma control in clinical settings

BACKGROUND

The Asthma Control Test (ACT) is frequently used for the evaluation of asthma control in clinical care setting because it does not require the use of pulmonary function tests, which can be difficult for general practitioners to use. However, few large-scale studies have investigated the efficacy of the Japanese version ACT (J-ACT) in actual use during clinical care.

METHODS

The aim of this study was to analyze the efficacy of the J-ACT in a clinical care setting. Using data from a 2008 questionnaire survey including the J-ACT by the Niigata Asthma Treatment Study Group, we compared the ACT scores of 2233 patients with respect to multiple parameters, including the severity by Japanese Society of Allergology and the attack frequency. Using the definition of asthma control partially referred to Global Initiative for Asthma (GINA) guidelines from the survey data, the accuracy screening and determination of optimal ACT cutpoints were performed by retrospective analysis.

RESULTS

Cronbach's α for the J-ACT was 0.785. Patients with more severe asthma and more frequent asthma attacks had lower ACT scores than did patients with less severe, less frequent attacks. The optimal ACT cutpoints were 24 for the controlled asthma and 20 for the uncontrolled asthma.

CONCLUSIONS

Our study, the first large-scale investigation of the efficacy of the J-ACT, determined that this evaluation tool is highly efficacious in establishing the level of asthma control. However, the determination of accurate cutpoints for the J-ACT will require more clear definitions of asthma control in future prospective studies.

Concave pattern of a maximal expiratory flow-volume curve: a sign of airflow limitation in adult bronchial asthma

Background. In patients with bronchial asthma, spirometry could identify the airflow limitation of small airways by evaluating the concave shape of the maximal expiratory flow-volume (MEFV) curve. As the concave shape of the MEFV curve is not well documented, we reevaluated the importance of this curve in adult asthmatic patients. Methods. We evaluated spirometric parameters, the MEFV curve, and its concave shape (scoop between the peak and endpoint of expiration) in 27 nonsmoking asthmatic patients with physician-confirmed wheeze and positive bronchial reversibility after a short-acting β2-agonist inhalation. We also calculated angle β and shape factors (SF_25% and SF_50%) to quantitate the curvilinearity of the MEFV curve. Results. The MEFV curve was concave in all patients. Along with improvements in standard spirometric parameters, curvilinear parameters, angle β, SF_25%, and SF_50% were significantly improved after bronchodilator inhalation. There were significant correlations between improvements in angle β, and FEF_50%, and FEF_25-75%, and between improvements in SF_25%, and SF_50%, and FEF_75%. Conclusions. The bronchodilator greatly affected the concave shape of the MEFV curve, correlating with spirometric parameters of small airway obstructions (FEF_50%, FEF_75%, and FEF_25-75%). Thus, the concave shape of the MEFV curve is an important indicator of airflow limitation in adult asthmatic patients.