Seasonal and geographic variations in the incidence of asthma exacerbations in the United States

Geographic variation in disease burden among patients with severe persistent asthma in the United States

BACKGROUND

In the United States, a few studies have evaluated geographic variation of severe asthma at the subnational level.

OBJECTIVE

To assess state-level geographic variation in the prevalence and characteristics of severe persistent asthma in the United States.

METHODS

Patients aged above or equal to 12 years with severe persistent asthma were identified using nationally representative data from IQVIA open-source Medical/Pharmacy Claims and PharMetrics Plus databases (January 2019-December 2020). The index date was defined as the patient's earliest qualifying date for a severe asthma diagnosis. Baseline characteristics were measured during the 12-month pre-index period. Outcomes including exacerbation occurrence, asthma control, and medication use were measured during the 12-month post-index period and compared across states using census-level projections.

RESULTS

A total of 2,092,799 patients with asthma were identified; 496,750 (23.7%) met criteria for severe persistent asthma and all inclusion criteria. Mean age was 50.5 years; 68.4% were females. The prevalence of severe persistent asthma varied across states, ranging from 19.6% (New Mexico) to 31.9% (Alaska). Among patients with severe persistent asthma, 40.9% had more than or equal to 1 exacerbation, ranging from 34.2% (Vermont) to 45.6% (Louisiana); 21.1% had uncontrolled disease, ranging from 16.5% (Vermont) to 24.0% (Arizona). Among patients with exacerbations, 13.7% had exacerbation-related emergency department visits or hospitalizations, ranging from 7.0% (North Carolina) to 17.7% (Nevada). Among patients with severe uncontrolled asthma, 15.6% used biologics post-index, ranging from 2.2% (Hawaii) to 27.9% (Mississippi).

CONCLUSION

There is significant variability in severe persistent asthma prevalence and disease burden across US states. Reasons for geographic variation may include differences in socioeconomic/environmental factors or asthma management.

Tezepelumab reduces exacerbations across all seasons in patients with severe, uncontrolled asthma (NAVIGATOR)

BACKGROUND

Asthma exacerbation frequencies vary throughout the year owing to seasonal triggers. Tezepelumab is a human monoclonal antibody that targets thymic stromal lymphopoietin. In the phase 3 NAVIGATOR study (NCT03347279), tezepelumab significantly reduced the annualized asthma exacerbation rate (AAER) vs placebo in patients with severe, uncontrolled asthma.

OBJECTIVE

To evaluate the effect of tezepelumab on asthma exacerbations across all seasons in NAVIGATOR patients (post hoc).

METHODS

NAVIGATOR was a multicenter, randomized, double-blind, placebo-controlled study. Patients (12-80 years old) were randomized 1:1 to tezepelumab 210 mg or placebo subcutaneously every 4 weeks for 52 weeks. AAER over 52 weeks was assessed by season. Data from patients in the Southern Hemisphere were transformed to align with Northern Hemisphere seasons.

RESULTS

Tezepelumab reduced the AAER vs placebo by 63% (95% confidence interval [CI], 52-72) in winter, 46% (95% CI, 26-61) in spring, 62% (95% CI, 48-73) in summer, and 54% (95% CI, 41-64) in fall. In matched climates, during the spring allergy season (March 1 to June 15) and ragweed allergy season (September), tezepelumab reduced the AAER vs placebo in patients with seasonal allergy by 59% (95% CI, 29-77) and 70% (95% CI, 33-87), respectively. In patients with perennial allergy and in those with seasonal allergy, tezepelumab reduced the AAER vs placebo across all seasons.

CONCLUSION

Tezepelumab reduced exacerbations across all seasons vs placebo in patients with severe, uncontrolled asthma, including patients with seasonal and perennial allergies. These data further support the efficacy of tezepelumab in a broad population of patients with severe, uncontrolled asthma.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03347279 (https://clinicaltrials.gov/ct2/show/NCT03347279).

Advances in pulmonary rehabilitation for children with bronchial asthma

Bronchial asthma is a heterogeneous disease characterized by chronic airway inflammation and airway hyperresponsiveness. With the development of the whole-life-cycle health concept, the focus of treatment for bronchial asthma in children has gradually shifted from pharmacological control to an integrated management model of functional rehabilitation and pharmacological assistance. As a non-pharmacological integrated approach, pulmonary rehabilitation plays an equally important role in the management of childhood asthma as pharmacological treatments. Breathing techniques such as Buteyko breathing, pursed lip breathing, diaphragmatic breathing training, threshold-pressure inspiratory muscle training and yoga breathing can improve lung function indicators such as forced expiratory volume in first second (FEV1), forced vital capacity (FVC), peak expiratory flow (PEF) and maximal voluntary ventilation (MVV) in children. Comprehensive pre-exercise assessment, development of exercise prescriptions, and implementation and evaluation of exercise effects can improve physical fitness, neuromuscular coordination, and self-confidence of children with asthma. The comprehensive interventions of health education, psychological support and nutritional intervention can improve the compliance and effectiveness of rehabilitation training. This article reviews the research progress on respiratory training, physical exercise, and comprehensive interventions in the pulmonary rehabilitation of asthmatic children, to provide theoretical basis and practical guidance for the scientific and rational management of pulmonary rehabilitation of asthmatic children in clinical settings.

A digital approach to asthma self-management in adults: Protocol for a pragmatic randomized controlled trial

Asthma self-management can improve symptom control, but adherence to established self-management behaviors is often poor. With adult asthma uncontrolled in over 60% of U.S. cases, there is a need for scalable, cost-effective tools to improve asthma outcomes. Here we describe a protocol for the Asthma Digital Study, a 24-month, decentralized, pragmatic, open-label, randomized controlled trial investigating the impact of a digital asthma self-management (DASM) program on asthma outcomes in adults. The program leverages consumer-grade devices with a smartphone app to provide "smart nudges," symptom logging, trigger tracking, and other features. Participants are recruited (target N = 900) from throughout the U.S., and randomized to a DASM or control arm (1:1). Co-primary outcomes at one year are a) asthma-associated costs for acute care and b) change from baseline in Asthma Control Test™ scores. Findings may inform decisions around adoption of digital tools for asthma self-management. Trial registration:clinicaltrials.gov identifier: NCT04609644. Registered: Oct 30, 2020.

Joint association between ambient air pollutant mixture and pediatric asthma exacerbations

Exposure to air pollutants is known to exacerbate asthma, with prior studies focused on associations between single pollutant exposure and asthma exacerbations. As air pollutants often exist as a complex mixture, there is a gap in understanding the association between complex air pollutant mixtures and asthma exacerbations. We evaluated the association between the air pollutant mixture (52 pollutants) and pediatric asthma exacerbations.

Method

This study focused on children (age ≤ 19 years) who lived in Douglas County, Nebraska, during 2016-2019. A seasonal-scale joint association between the outdoor air pollutant mixture adjusting for potential confounders (temperature, precipitation, wind speed, and wind direction) in relation to pediatric asthma exacerbation-related emergency department (ED) visits was evaluated using the generalized weighted quantile sum (qWQS) regression with repeated holdout validation.

Results

We observed associations between air pollutant mixture and pediatric asthma exacerbations during spring (lagged by 5 days), summer (lag 0-5 days), and fall (lag 1-3 days) seasons. The estimate of the joint outdoor air pollutant mixture effect was higher during the summer season (adjusted-β_WQS = 1.11, 95% confidence interval [CI]: 0.66, 1.55), followed by spring (adjusted-β_WQS = 0.40, 95% CI: 0.16, 0.62) and fall (adjusted-β_WQS = 0.20, 95% CI: 0.06, 0.33) seasons. Among the air pollutants, PM_2.5, pollen, and mold contributed higher weight to the air pollutant mixture.

Conclusion

There were associations between outdoor air pollutant mixture and pediatric asthma exacerbations during the spring, summer, and fall seasons. Among the 52 outdoor air pollutant metrics investigated, PM_2.5, pollen (sycamore, grass, cedar), and mold (Helminthosporium, Peronospora, and Erysiphe) contributed the highest weight to the air pollutant mixture.

Targeting TSLP in Asthma

Thymic stromal lymphopoietin (TSLP) is an epithelial cell-derived cytokine implicated in the initiation and persistence of inflammatory pathways in asthma. Released in response to a range of epithelial insults (eg, allergens, viruses, bacteria, pollutants, and smoke), TSLP initiates multiple downstream innate and adaptive immune responses involved in asthma inflammation. Inhibition of TSLP is postulated to represent a novel approach to treating the diverse phenotypes and endotypes of asthma. Tezepelumab, the TSLP inhibitor farthest along in clinical development, is a human monoclonal antibody (IgG2λ) that binds specifically to TSLP, preventing interactions with its heterodimeric receptor. Results of recently published phase 2 and 3 studies, reviewed in this article, provide evidence of the safety and efficacy of tezepelumab that builds on initial findings. Tezepelumab is safe, well tolerated, and provides clinically meaningful improvements in asthma control, including reduced incidence of exacerbations and hospitalizations in patients with severe asthma. Clinical benefits were associated with reductions in levels of a broad spectrum of cytokines (eg, interleukin [IL]-5, IL-13) and baseline biomarkers (eg, blood eosinophils, immunoglobulin [Ig]E, fractional exhaled nitric oxide [FeNO]) and were observed across a range of severe asthma phenotypes (ie, eosinophilic and non-eosinophilic). These data strengthen the notion that anti-TSLP elicits broad inhibitory effects on pathways that are key to asthma inflammation rather than on narrower inhibition of individual downstream factors. This review presents the rationale for targeting TSLP to treat asthma, as well as the clinical effects of TSLP blockade on asthma outcomes, biomarkers of disease activity, airway inflammation, lung physiology, and patient symptoms.

Weekend Versus Weekday Asthma-Related Emergency Department Utilization

OBJECTIVE

To assess variation in asthma-related emergency department (ED) use between weekends and weekdays.

METHODS

Cross-sectional administrative claims-based analysis using California 2016 Medicaid data and Vermont 2016 and Massachusetts 2015 all-payer claims databases. We defined ED use as the rate of asthma-related ED visits per 100 child-years. A weekend visit was a visit on Saturday or Sunday, based on date of ED visit claim. We used negative binomial regression and robust standard errors to assess variation between weekend and weekday rates, overall and by age group.

RESULTS

We evaluated data from 398,537 patients with asthma. The asthma-related ED visit rate was slightly lower on weekends (weekend: 18.7 [95% confidence interval (CI): 18.3-19.0], weekday: 19.6 [95% CI, 19.3-19.8], P < .001). When stratifying by age group, 3- to 5-year-olds had higher rates of asthma-related ED visits on weekends than weekdays (weekend: 33.7 [95% CI, 32.6-34.7], weekday: 29.8 [95% CI, 29.1-30.5], P < .001) and 12- to 17-year-olds had lower rates of ED visits on weekends than weekdays (weekend: 13.0 [95% CI: 12.5-13.4], weekday: 16.3 [95% CI: 15.9-16.7], P < .001). In the other age groups (6-11, 18-21 years) there were not statistically significant differences between weekend and weekday rates (P > .05).

CONCLUSIONS

In this multistate analysis of children with asthma, we found limited overall variation in pediatric asthma-related ED utilization on weekends versus weekdays. These findings suggest that increasing access options during the weekend may not necessarily decrease asthma-related ED use.

Coronavirus disease 2019 and pediatric asthma: friend or foe?

PURPOSE OF REVIEW

The interplay of asthma and coronavirus disease 2019 (COVID-19) in children is yet unknown. The purpose of this review is to determine the interplay of asthma and asthma therapeutics and COVID-19.

RECENT FINDINGS

There is no evidence to date that asthma is a risk factor for more severe COVID-19 outcomes, especially in children. There is actually some basis to suggest that children with atopic asthma may be at reduced risk of asthma exacerbations during COVID-19. The impact of asthma therapeutics on COVID-19 outcomes is unclear, but guidance is relatively uniform in recommending that those with asthma remain on current asthma medications. A focus on social determinants of health may be increasingly important during the pandemic and beyond.

SUMMARY

Asthma in children appears to be more friend, than foe, during COVID-19.

Estimated Mortality and Morbidity Attributable to Smoke Plumes in the United States: Not Just a Western US Problem

As anthropogenic emissions continue to decline and emissions from landscape (wild, prescribed, and agricultural) fires increase across the coming century, the relative importance of landscape-fire smoke on air quality and health in the United States (US) will increase. Landscape fires are a large source of fine particulate matter (PM2.5), which has known negative impacts on human health. The seasonal and spatial distribution, particle composition, and co-emitted species in landscape-fire emissions are different from anthropogenic sources of PM2.5. The implications of landscape-fire emissions on the sub-national temporal and spatial distribution of health events and the relative health importance of specific pollutants within smoke are not well understood. We use a health impact assessment with observation-based smoke PM2.5 to determine the sub-national distribution of mortality and the sub-national and sub-annual distribution of asthma morbidity attributable to US smoke PM2.5 from 2006 to 2018. We estimate disability-adjusted life years (DALYs) for PM2.5 and 18 gas-phase hazardous air pollutants (HAPs) in smoke. Although the majority of large landscape fires occur in the western US, we find the majority of mortality (74%) and asthma morbidity (on average 75% across 2006-2018) attributable to smoke PM2.5 occurs outside the West, due to higher population density in the East. Across the US, smoke-attributable asthma morbidity predominantly occurs in spring and summer. The number of DALYs associated with smoke PM2.5 is approximately three orders of magnitude higher than DALYs associated with gas-phase smoke HAPs. Our results indicate awareness and mitigation of landscape-fire smoke exposure is important across the US.

INEXAS: A Phase 2 Randomized Trial of On-demand Inhaled Interferon Beta-1a in Severe Asthmatics

BACKGROUND

Upper respiratory tract infections (URTIs) are important triggers for asthma exacerbations. We hypothesized that inhalation of the anti-viral cytokine, interferon (IFN)-β, during URTI, could prevent these exacerbations.

OBJECTIVE

To evaluate the efficacy of on-demand inhaled IFN-β1a (AZD9412) to prevent severe asthma exacerbations following symptomatic URTI.

METHODS

This was a randomized, double-blind, placebo-controlled trial in which patients with severe asthma (GINA 4-5; n = 121) reporting URTI symptoms were randomized to 14 days of once-daily nebulized AZD9412 or placebo. The primary endpoint was severe exacerbations during treatment. Secondary endpoints included 6-item asthma control questionnaire (ACQ-6) and lung function. Exploratory biomarkers included IFN-response markers in serum and sputum, blood leucocyte counts and serum inflammatory cytokines.

RESULTS

Following a pre-planned interim analysis, the trial was terminated early due to an unexpectedly low exacerbation rate. Asthma worsenings were generally mild and tended to peak at randomization, possibly contributing to the lack of benefit of AZD9412 on other asthma endpoints. Numerically, AZD9412 did not reduce severe exacerbation rate, ACQ-6, asthma symptom scores or reliever medication use. AZD9412 improved lung function (morning peak expiratory flow; mPEF) by 19.7 L/min. Exploratory post hoc analyses indicated a greater mPEF improvement by AZD9412 in patients with high blood eosinophils (>0.3 × 109 /L) at screening and low serum interleukin-18 relative change at pre-treatment baseline. Pharmacodynamic effect of AZD9412 was confirmed using IFN-response markers.

CONCLUSIONS & CLINICAL RELEVANCE

Colds did not have the impact on asthma patients that was expected and, due to the low exacerbation rate, the trial was stopped early. On-demand AZD9412 treatment did not numerically reduce the number of exacerbations, but did attenuate URTI-induced worsening of mPEF. Severe asthma patients with high blood eosinophils or low serum interleukin-18 response are potential subgroups for further investigation of inhaled IFN-β1a.

Tezepelumab Reduces Exacerbations Across All Seasons in Patients with Severe, Uncontrolled Asthma: A Post Hoc Analysis of the PATHWAY Phase 2b Study

Introduction

Tezepelumab is a human monoclonal antibody that blocks thymic stromal lymphopoietin (TSLP), an epithelial cytokine implicated in airway inflammation in asthma, from binding to its heterodimeric receptor. In the PATHWAY phase 2b study, tezepelumab significantly reduced exacerbation rates compared with placebo in adults with severe, uncontrolled asthma, irrespective of baseline disease characteristics.

Objective

To evaluate the effect of tezepelumab on asthma exacerbations on a seasonal basis.

Methods

This was a post hoc analysis of the PATHWAY study (NCT02054130). Adults (N=550) with severe, uncontrolled asthma were randomized 1:1:1:1 to receive subcutaneous tezepelumab 70 mg every 4 weeks (Q4W), 210 mg Q4W or 280 mg every 2 weeks (Q2W), or placebo Q2W, for 52 weeks. The annualized asthma exacerbation rate (AAER), total number of days with an exacerbation, proportion of patients with at least one exacerbation or 0, 1 or ≥2 exacerbations, and proportion of patients experiencing an exacerbation per day were evaluated by season and over the year, by treatment in the overall study population and in subgroups according to baseline blood eosinophil count (≥300 cells/µL or <300 cells/µL) or atopic asthma status (fluoro-enzyme immunoassay [FEIA]+ or FEIA-).

Results

Seasonal variations in exacerbation rates were found, with peaks observed in fall and winter, and greater variations in patients with high blood eosinophil counts (≥300 cells/µL). Tezepelumab treatment consistently reduced exacerbation rates across all seasons compared with placebo. Furthermore, there was a trend, which was not significant, toward a reduction in the total number of days with exacerbations and in the proportion of patients with exacerbations during each season in patients treated with tezepelumab compared with those who received placebo, irrespective of blood eosinophil count or atopic asthma status.

Conclusion

Tezepelumab reduced exacerbations across all seasons, irrespective of evaluated baseline disease characteristics. These data support the efficacy of tezepelumab in a broad population of patients with severe, uncontrolled asthma.

Switch from IL-5 to IL-5-Receptor α Antibody Treatment in Severe Eosinophilic Asthma

Background

Anti-IL-5 antibodies represent an established therapy for severe eosinophilic asthma (SEA), but some patients show inadequate response. The objective of this study was to assess the effects of a switch to anti-IL-5Rα therapy in patients with inadequate response to anti-IL-5 therapy.

Methods

In this retrospective multi-centre, real-life study, we analysed all SEA patients switched from anti-IL-5 to anti-IL-5Rα therapy due to inadequate response or intolerability. Pulmonary function tests, blood gas analyses, asthma control tests (ACT) and oral corticosteroid (OCS) usage were analysed and compared at three timepoints: baseline (BL, before anti-IL-5 therapy), timepoint 1 (T1, under anti-IL-5 therapy) and timepoint 2 (T2, under anti-IL-5Rα therapy).

Results

Of 665 patients treated with anti-IL-5 antibodies, 70 were switched to anti-IL-5Rα and 60 were included in the analysis. Median treatment duration was 8 months [IQR 5; 15] for anti-IL-5 and 5 months [IQR 4; 6] for anti-IL-5Rα therapy. FEV₁ was 61% of predicted at BL [IQR 41; 74], 61% [IQR 43; 79] at T1 and 68% [IQR 49; 87] at T2 (p_T1-T2=0.011). ACT score was 10 [IQR 8; 13], 16 [IQR 10; 19] and 19 [IQR 14; 22], respectively (both p<0.001). The number of patients requiring OCS was reduced from 41 (BL) to 32 (T1) and 19 (T2) (both p<0.001). Ten patients discontinued anti-IL-5Rα therapy due to insufficient efficacy (n=7) and adverse events (n=3).

Conclusion

Switching from anti-IL-5 to anti-IL-5Rα therapy in patients with inadequate response was associated with significantly improved FEV₁, asthma control and OCS reduction.

Age-Specific Associations of Ozone and Fine Particulate Matter with Respiratory Emergency Department Visits in the United States

RATIONALE

Whereas associations between air pollution and respiratory morbidity for adults 65 years and older are well documented in the United States, the evidence for people under 65 is less extensive. To address this gap, the Centers for Disease Control and Prevention's National Environmental Public Health Tracking Program collected respiratory emergency department (ED) data from 17 states.

OBJECTIVES

To estimate age-specific acute effects of ozone and fine particulate matter (particulate matter ≤2.5 mm in aerodynamic diameter [PM_2.5]) on respiratory ED visits.

METHODS

We conducted time-series analyses in 894 counties by linking daily respiratory ED visits with estimated ozone and PM_2.5 concentrations during the week before the date of the visit. Overall effect estimates were obtained with a Bayesian hierarchical model to combine county estimates for each pollutant by age group (children, 0-18; adults, 19-64; adults ≥ 65, and all ages) and by outcome group (acute respiratory infection, asthma, chronic obstructive pulmonary disease, pneumonia, and all respiratory ED visits).

MEASUREMENTS AND MAIN RESULTS

Rate ratios (95% credible interval) per 10-μg/m³ increase in PM_2.5 and all respiratory ED visits were 1.024 (1.018-1.029) among children, 1.008 (1.004-1.012) among adults younger than 65 years, and 1.002 (0.996-1.007) among adults 65 and older. Per 20-ppb increase in ozone, rate ratios were 1.017 (1.011-1.023) among children, 1.051 (1.046-1.056) among adults younger than 65, and 1.033 (1.026-1.040) among adults 65 and older. Associations varied in magnitude by age group for each outcome group.

CONCLUSIONS

These results address a gap in the evidence used to ensure adequate public health protection under national air pollution policies.

Epidemiology and Outcomes of Hospitalized Inflammatory Bowel Disease Patients with Asthma in the United States

Introduction Research on the epidemiology and outcomes of hospitalized inflammatory bowel disease (IBD) patients with a history of asthma in the United States (US) is limited. This study aimed at identifying the sociodemographic and clinical characteristics of hospitalized IBD patients with a diagnosis of asthma. We also examined the association between an asthma diagnosis and the length of stay (LOS) and in-hospital mortality among hospitalized IBD patients. Method Using the National Inpatient Sample (NIS) for the years 2008-2013 and the ninth edition of the International Classification of Diseases codes, we identified adult hospitalized patients with IBD (N = 370,636) and used weighted multilevel hierarchical logistic regression models. Results The overall prevalence of asthma in our cohort of hospitalized IBD patients was 8%. Hospitalized IBD patients with asthma were more likely to be female, <45 years old, have Crohn's disease, and a higher Elixhauser comorbidity index (ECI). IBD patients with ECI of 3 or more had higher odds of having a prior diagnosis of asthma compared to those with no comorbidities (OR 63.33, 95% CI: 54.51-73.58). Having a prior diagnosis of asthma among hospitalized IBD patients was associated with lower odds of prolonged hospital stay and in-hospital mortality (OR 0.72, 95% CI: 0.69-0.74; OR 0.49, 95% CI: 0.43- 0.56, respectively). Patients with both IBD and asthma are more likely to seek medical care with earlier and aggressive treatment modalities, which may explain the lower in-hospital mortality in this group. Conclusion Lower in-hospital mortality and geographic variation are notable in the outcomes of IBD patients with asthma. Future prospective studies are necessary to improve our understanding of the management and interplay of IBD patients with asthma.

A Comparison of Leukotriene Receptor Antagonists to Low-Dose Inhaled Corticosteroids in the Elderly with Mild Asthma

BACKGROUND

Although elderly patients with asthma have clinical characteristics different from those of young adults, few studies or guidelines have focused on specific treatments for this population.

OBJECTIVE

This study compared the effectiveness of leukotriene receptor antagonists (LTRAs) versus inhaled corticosteroids (ICSs) in elderly patients with asthma in real-world settings.

METHODS

We extracted records for elderly patients with asthma who were newly prescribed LTRAs or low-dose ICSs from January 2003 to December 2010 from National Sample Cohort data of Korea. We defined the first prescription date for each medication as the index date. We compared the risks of asthma exacerbation between the 2 groups using Cox proportional-hazard regression after propensity score-based inverse probability of treatment weighting to balance covariates between treatment groups. We also compared asthma-related health care resource utilization and medication compliance in both groups using chi-square test and t test.

RESULTS

The number of identified patients newly treated with LTRAs and low-dose ICSs was 1571 and 121, respectively. The risks of asthma exacerbation in the LTRA and low-dose ICS groups after weighting were not significantly different (hazard ratio, 0.98; 95% CI, 0.65-1.54). The proportion with high compliance (medication possession ratio ≥ 80%) in the LTRA group was higher than that in the low-dose ICS group.

CONCLUSIONS

The effectiveness of LTRAs was not different from that of low-dose ICSs regarding the risk of asthma exacerbation in elderly patients with asthma in real-world settings. Given the practical benefits gained from convenient administration, LTRAs can be considered a reasonable alternative first-line therapy for elderly patients with mild asthma.

Seasonal variation in asthma exacerbations in the AUSTRI and VESTRI studies

Seasonal peaks in asthma exacerbations are well described, as is the age-dependent nature of the magnitude of these peaks [1]. Children with asthma experience seasonal peaks in exacerbation frequency, which vary according to geographical location and climate [1–3]. Previous studies have examined the effect of season on the efficacy of pharmacological interventions. The anti-immunoglobulin-E monoclonal antibody omalizumab showed an increase in treatment benefits compared with placebo in the autumn and spring versus summer months in children, adolescents and young adults with allergic asthma in the USA [4]. In contrast, the anti-interleukin-5 monoclonal antibody mepolizumab showed no effect of seasonal differences in adolescents and adults with severe eosinophilic asthma [5].

Seasonal variation in the benefit of LABA/ICS versus ICS on asthma exacerbation rate is observed in children.http://ow.ly/pcZF30o8hHk

Analysis of wheeze sounds during tidal breathing according to severity levels in asthma patients

Objective: This study aimed to statistically analyze the behavior of time-frequency features in digital recordings of wheeze sounds obtained from patients with various levels of asthma severity (mild, moderate, and severe), and this analysis was based on the auscultation location and/or breath phase. Method: Segmented and validated wheeze sounds were collected from the trachea and lower lung base (LLB) of 55 asthmatic patients during tidal breathing maneuvers and grouped into nine different datasets. The quartile frequencies F₂₅, F₅₀, F₇₅, F₉₀ and F₉₉, mean frequency (MF) and average power (AP) were computed as features, and a univariate statistical analysis was then performed to analyze the behavior of the time-frequency features. Results: All features generally showed statistical significance in most of the datasets for all severity levels [χ² = 6.021-71.65, p < 0.05, η² = 0.01-0.52]. Of the seven investigated features, only AP showed statistical significance in all the datasets. F₂₅, F₇₅, F₉₀ and F₉₉ exhibited statistical significance in at least six datasets [χ² = 4.852-65.63, p < 0.05, η² = 0.01-0.52], and F₂₅, F₅₀ and MF showed statistical significance with a large η² in all trachea-related datasets [χ² = 13.54-55.32, p < 0.05, η² = 0.13-0.33]. Conclusion: The results obtained for the time-frequency features revealed that (1) the asthma severity levels of patients can be identified through a set of selected features with tidal breathing, (2) tracheal wheeze sounds are more sensitive and specific predictors of severity levels and (3) inspiratory and expiratory wheeze sounds are almost equally informative.

Seasonal changes influence the improvement in asthma symptoms by exercise training in subjects with asthma*

OBJECTIVE

To investigate whether patients with moderate-to-severe asthma who commence an exercise training program in winter or summer show differences in exercise capacity, health-related quality of life (HRQoL) and asthma symptoms.

METHODS

Forty-two consecutive subjects visiting the outpatient clinic were enrolled in the 17-week rehabilitation program. One group of patients received the intervention from summer to winter (SWG, n = 21), and the other group participated from winter to summer (WSG, n = 21). Before and after the exercise training program, all patients were evaluated by cardiopulmonary exercise test, pulmonary function test, quality of life questionnaire and a daily diary that evaluated clinical asthma symptoms.

RESULTS

After the training period, both groups improved similarly in health-related quality of life (HRQoL) and aerobic capacity. The WSG patients had a greater increase that those in the SWG in asthma symptom-free days (p < 0.05).

CONCLUSIONS

Our results indicate that seasonal variations affect the improvement in asthma symptoms after an exercise training program but have no effect on health-related quality of life, exercise capacity or pulmonary function.

Anti-IL-5 therapy in patients with severe eosinophilic asthma - clinical efficacy and possible criteria for treatment response

Background

Interleukin-5 (IL-5) antibodies represent a promising therapeutic option for patients with severe eosinophilic asthma. To date, no official treatment response criteria exist. In this study, simple criteria for treatment response applicable to all asthma patients were used to evaluate clinical efficacy and predictors for treatment response in a real-life setting.

Methods

Data from 42 patients with severe eosinophilic asthma treated with mepolizumab for at least six months were analysed. Simple criteria to assess treatment response in clinical practice were used: increase of FEV₁ ≥ 12% or ≥ 200 ml, reduction of blood eosinophils (< 150/μl or < 80% from baseline) and improvement of subjective condition (patient-judged subjective improvement or worsening following therapy). Patients were considered treatment responders if two criteria were fulfilled.

Results

Thirty-two out of 42 patients (76% [61–87%]) were classified as responders. Within the groups (responder vs non-responder), treatment with mepolizumab led to significant increase in FEV₁ (+ 600 ml vs -100 ml, p = 0.003), oxygenation (+ 8 mmHg vs -3 mmHg, p = 0.001), quality of life (visual analogue scale; + 28% vs − 5%, p = 0.004) and Asthma Control Test (+ 8 vs + 1 points, p = 0.002). In the responder group a significant decrease in the exacerbation rate over 12 months (1.45 vs 0.45, p = 0.002) was observed. Baseline characteristics (sex, BMI, smoking history, allergies, baseline level of eosinophils) did not predict treatment response.

Conclusion

Using improvement of lung function, decrease of eosinophils and improvement of subjective condition as response criteria, 76% of treated patients could be classified as treatment responders, demonstrating the efficacy of anti-IL-5 therapy in clinical practice.

Integrating Smart Health in the US Health Care System: Infodemiology Study of Asthma Monitoring in the Google Era

BACKGROUND

With the internet's penetration and use constantly expanding, this vast amount of information can be employed in order to better assess issues in the US health care system. Google Trends, a popular tool in big data analytics, has been widely used in the past to examine interest in various medical and health-related topics and has shown great potential in forecastings, predictions, and nowcastings. As empirical relationships between online queries and human behavior have been shown to exist, a new opportunity to explore the behavior toward asthma-a common respiratory disease-is present.

OBJECTIVE

This study aimed at forecasting the online behavior toward asthma and examined the correlations between queries and reported cases in order to explore the possibility of nowcasting asthma prevalence in the United States using online search traffic data.

METHODS

Applying Holt-Winters exponential smoothing to Google Trends time series from 2004 to 2015 for the term "asthma," forecasts for online queries at state and national levels are estimated from 2016 to 2020 and validated against available Google query data from January 2016 to June 2017. Correlations among yearly Google queries and between Google queries and reported asthma cases are examined.

RESULTS

Our analysis shows that search queries exhibit seasonality within each year and the relationships between each 2 years' queries are statistically significant (P<.05). Estimated forecasting models for a 5-year period (2016 through 2020) for Google queries are robust and validated against available data from January 2016 to June 2017. Significant correlations were found between (1) online queries and National Health Interview Survey lifetime asthma (r=-.82, P=.001) and current asthma (r=-.77, P=.004) rates from 2004 to 2015 and (2) between online queries and Behavioral Risk Factor Surveillance System lifetime (r=-.78, P=.003) and current asthma (r=-.79, P=.002) rates from 2004 to 2014. The correlations are negative, but lag analysis to identify the period of response cannot be employed until short-interval data on asthma prevalence are made available.

CONCLUSIONS

Online behavior toward asthma can be accurately predicted, and significant correlations between online queries and reported cases exist. This method of forecasting Google queries can be used by health care officials to nowcast asthma prevalence by city, state, or nationally, subject to future availability of daily, weekly, or monthly data on reported cases. This method could therefore be used for improved monitoring and assessment of the needs surrounding the current population of patients with asthma.

Assessment of temporally-related acute respiratory illness following influenza vaccination

•

We investigated risk of acute respiratory illness post-influenza vaccination.

•

Post-vaccination risk of non-influenza respiratory pathogen was higher in children.

•

Patient perceptions of illness following influenza vaccination may be supported.

•

Assessments of potential mechanisms for findings are needed.

Background

A barrier to influenza vaccination is the misperception that the inactivated vaccine can cause influenza. Previous studies have investigated the risk of acute respiratory illness (ARI) after influenza vaccination with conflicting results. We assessed whether there is an increased rate of laboratory-confirmed ARI in post-influenza vaccination periods.

Methods

We conducted a cohort sub-analysis of children and adults in the MoSAIC community surveillance study from 2013 to 2016. Influenza vaccination was confirmed through city or hospital registries. Cases of ARI were ascertained by twice-weekly text messages to household to identify members with ARI symptoms. Nasal swabs were obtained from ill participants and analyzed for respiratory pathogens using multiplex PCR. The primary outcome measure was the hazard ratio of laboratory-confirmed ARI in individuals post-vaccination compared to other time periods during three influenza seasons.

Results

Of the 999 participants, 68.8% were children, 30.2% were adults. Each study season, approximately half received influenza vaccine and one third experienced ≥1 ARI. The hazard of influenza in individuals during the 14-day post-vaccination period was similar to unvaccinated individuals during the same period (HR 0.96, 95% CI [0.60, 1.52]). The hazard of non-influenza respiratory pathogens was higher during the same period (HR 1.65, 95% CI [1.14, 2.38]); when stratified by age the hazard remained higher for children (HR 1·71, 95% CI [1.16, 2.53]) but not for adults (HR 0.88, 95% CI [0.21, 3.69]).

Conclusion

Among children there was an increase in the hazard of ARI caused by non-influenza respiratory pathogens post-influenza vaccination compared to unvaccinated children during the same period. Potential mechanisms for this association warrant further investigation. Future research could investigate whether medical decision-making surrounding influenza vaccination may be improved by acknowledging patient experiences, counseling regarding different types of ARI, and correcting the misperception that all ARI occurring after vaccination are caused by influenza.