Comprehensive Characterization of Difficult-to-Treat Asthma Reveals Near Absence of T2-Low Status

BACKGROUND

Asthma is conventionally stratified as type 2 inflammation (T2)-high or T2-low disease. Identifying T2 status has therapeutic implications for patient management, but a real-world understanding of this T2 paradigm in difficult-to-treat and severe asthma remains limited.

OBJECTIVES

To identify the prevalence of T2-high status in difficult-to-treat asthma patients using a multicomponent definition and compare clinical and pathophysiologic characteristics between patients classified as T2-high and T2-low.

METHODS

We evaluated 388 biologic-naive patients from the Wessex Asthma Cohort of difficult asthma (WATCH) study in the United Kingdom. Type 2-high asthma was defined as 20 parts per billion or greater FeNO , 150 cells/μL or greater peripheral blood eosinophils, the need for maintenance oral corticosteroids, and/or clinically allergy-driven asthma.

RESULTS

This multicomponent assessment identified T2-high asthma in 93% of patients (360 of 388). Body mass index, inhaled corticosteroid dose, asthma exacerbations, and common comorbidities did not differ by T2 status. Significantly worse airflow limitation was found in T2-high compared with T2-low patients (FEV1/FVC 65.9% vs 74.6%). Moreover, 75% of patients defined as having T2-low asthma had raised peripheral blood eosinophils within the preceding 10 years, which left only seven patients (1.8%) who had never had T2 signals. Incorporation of sputum eosinophilia 2% or greater into the multicomponent definition in a subset of 117 patients with induced sputum data similarly found that 96% (112 of 117) met criteria for T2-high asthma, 50% of whom (56 of 112) had sputum eosinophils 2% or greater.

CONCLUSIONS

Almost all patients with difficult-to-treat asthma have T2-high disease; less than 2% of patients never display T2-defining criteria. This highlights a need to assess T2 status comprehensively in clinical practice before labeling a patient with difficult-to-treat asthma as T2-low.

Factors to Consider in Prescribing Asthma Biologic Therapies to Children

The increasing availability of biologics, both by expanding age indications and by development of new therapies, provides additional options to treat children and adolescents with severe asthma. However, the evidence for these biologics in these populations is limited compared with that for adult studies. As such, before initiation of therapy, possible alternative therapies that can also provide asthma control, confirmation of the diagnosis of asthma, management of comorbidities, and assessment of adherence should be explored. The choice of a biologic should be a shared decision-making process between providers and families, balancing biologic efficacy, goals of care, administration, and ability to treat multiple conditions. Response to treatment should be periodically evaluated not only to ensure an ineffective treatment is not continued but also to consider when to potentially discontinue therapy should it be beneficial. The utilization of biologics in children and adolescents with severe asthma also leads to unanswered questions on their role in disease remission and long-term outcomes.

Shuttle walk test categorization according to the qualifiers of the International Classification of Functioning, Disability, and Health: proposal for use in patients with difficult-to-treat asthma, a cross-sectional study

AIM

To classify functional capacity of people with difficult-to-treat asthma based on the International Classification of Functioning, Disability and Health (ICF).

METHODS

Fifty-seven patients underwent the Incremental Shuttle Walk Test (ISWT) to assess functional capacity, in order to categorize them functionally we used the ICF qualifiers. To qualify ISWT results the individual's impairment (i.e. percentage of distance walked in relation to the percentage of predicted) was analyzed. Additionally, body mass index (BMI); physical activity level (IPAQ); and pulmonary function were evaluated. In order to analyze the difference between functional capacity levels, two groups were compared (i.e. mild/moderate vs. severe impairment); therefore, the participants were matched according to age and BMI and the unpaired Student t test was used.

RESULTS

Among the fifty-seven included individuals, only one (1.8%) presented mild functional capacity limitation, 12 (21.1%) moderate limitation and 44 (77.2%) severe limitation. There was a significant difference between the ISWT distance between groups (F = 0.217, p < .001). The other variables did not present differences between the mild/moderate and severe groups.

CONCLUSION

The ICF qualifiers were able to categorize the ISWT and classified the functional capacity limitation as mild, moderate and severe. Therefore, it has proved to be a useful clinical tool for evaluation, follow-up and clinical decision-making.

Difficult-to-Treat Asthma Management in School-Age Children

The World Health Organization divides severe asthma into three categories: untreated severe asthma; difficult-to-treat severe asthma; and severe, therapy-resistant asthma. The apparent frequency of severe asthma in the general population of asthmatic children is probably around 5%. Upon referral of these children, it is important to evaluate the diagnosis of asthma carefully before modifying management and applying a long-term monitoring plan. Identification of pathophysiologic phenotypes using objective biomarkers is essential in our routine assessments of severe asthma. Although conventional pharmacologic approaches should be attempted first, there is growing recognition that children with difficult-to-treat asthma may have unique clinical phenotypes that may necessitate alternative treatment approaches including asthma biologics. These new medications, especially those with effects on multiple pathologic features of asthma, raise the hope that new treatment strategies could induce remission. Besides introducing new medications, the opportunity for closer monitoring is feasible with advances in digital health. Therefore, we have the opportunity to improve response to medications, individualize treatment, and monitor response along with potential steps to prevent severe asthma.

[The diagnostic approach to difficult-to-treat asthma and severe asthma]

Difficult-to-treat asthma refers to asthma that is not controlled despite high or medium doses of inhaled steroids or in which high doses of treatment are required to maintain an adequate control of the symptoms and to reduce the risk of exacerbations. An inadequate technique to use the inhaler, poor adherence to treatment, smoking, comorbidities, or an incorrect diagnosis should be considered. In severe asthma, despite adherence to treatment with optimized maximum doses and the management of factors that could contribute, multiple medications in maximum doses are required to have an adequate therapeutic control or this is not achieved. The approach to these patients involves a meticulous process due to the multiple factors that can influence poor asthma control and that can lead to a misclassification of the disease when, in reality, the patient can be presenting different comorbidities whose treatment could decrease the severity of asthma symptoms and modify the prognosis. The objective of this document is to make the approach to patients with difficult-to-treat asthma and severe asthma known, as well as the most frequent comorbidities. A search was made in PubMed with the purpose of identifying the main pathologies that may be present in patients and, based on what is described in the literature, to propose a diagnostic approach. 100 studies were comprised in this review, including clinical guidelines such as GINA, GEMA, and ERS/ATS.

Disease Burden and Long-Term Risk of Persistent Very Poorly Controlled Asthma: TENOR II

BACKGROUND

Severe/difficult-to-treat disease occurs in 5% to 10% of patients with asthma, but accounts for more than 50% of related economic costs. Understanding factors associated with persistent very poorly controlled (VPC) asthma may improve outcomes.

OBJECTIVE

To characterize persistent VPC asthma after more than 10 years of standard of care.

METHODS

The Epidemiology and Natural history of asthma: Outcomes and treatment Regimens (TENOR) II (N = 341) was a multicenter, observational study of patients with severe/difficult-to-treat asthma with a single, cross-sectional visit more than 10 years after TENOR I. Persistent VPC asthma was defined as VPC asthma at TENOR I and TENOR II enrollment; without VPC asthma was defined as well- or not well-controlled asthma at either or both visits. Multivariable logistic regression assessed long-term predictors of persistent VPC asthma using TENOR I baseline variables.

RESULTS

Of 327 patients, nearly half (48.0%, n = 157) had persistent VPC asthma. Comorbidities and asthma triggers were more frequent in patients with persistent VPC asthma than in patients without VPC asthma. Total geometric mean IgE was higher in patients with persistent VPC asthma (89.3 IU/mL vs 55.7 IU/mL); there was no difference in eosinophil levels. Lung function was lower in patients with persistent VPC asthma (mean % predicted pre- and postbronchodilator FEV₁, 63.0% vs 82.8% and 69.6% vs 87.2%, respectively). Exacerbations in the previous year were more likely in patients with persistent VPC asthma (29.7% vs 9.0%, respectively). Predictors of persistent VPC asthma were black versus white race/ethnicity, allergic trigger count (4 vs 0), systemic corticosteroid use, and postbronchodilator FEV₁ (per 10% decrease).

CONCLUSIONS

The burden of persistent VPC asthma is high in severe/difficult-to-treat disease; management of modifiable risk factors, maximization of lung function, and trigger avoidance may improve outcomes.

The impact of dysfunctional breathing on the level of asthma control in difficult asthma

BACKGROUND

Difficult asthma is defined as asthma requiring high dose treatment. However, systematic assessment is required to differentiate severe asthma from difficult-to-treat asthma. Dysfunctional breathing (DB) is a common comorbidity in difficult asthma, which may contribute to symptoms, but how it affects commonly used measures of symptom control is unclear.

METHODS

All adult asthma patients seen in four respiratory clinics over one year were screened prospectively, and patients with possible severe asthma according to ERS/ATS criteria ('Difficult asthma': high-dose inhaled corticosteroids/oral corticosteroids), underwent systematic assessment. Symptoms of DB were assessed utilizing a symptom based subjective tool, Nijmegen questionnaire (NQ), and objective signs of DB with the Breathing Pattern Assessment Tool (BPAT). Asthma control and quality of life were evaluated with the Asthma Control Questionnaire (ACQ) and the mini Asthma Quality of Life Questionnaire (AQLQ).

RESULTS

A total of 117 patients were included. Among these, 29.9% (35/117) had DB according to the NQ. Patients with DB had a poorer asthma control (ACQ: Mean (SD) 2.86 ± 1.05 vs. 1.46 ± 0.93) and lower quality of life (AQLQ score: Mean (SD) 4.2 ± 1.04 vs. 5.49 ± 0.85) compared to patients without DB. Similarly, patients with objective signs of DB according to the BPAT score had worse asthma control: BPAT >4 vs < 4: (ACQ: Mean (SD) 3.15 ± 0.93 vs 2.03 ± 1.15).

CONCLUSION

DB is common among patients with difficult asthma, and is associated with significantly poorer asthma control and lower quality of life. Assessment and treatment of DB is an important part of the management of difficult asthma.

The Tempest: Difficult to Control Asthma in Adolescence

Severe asthma is associated with significant morbidity and is a highly heterogeneous disorder. Severe asthma in adolescence has some unique elements compared with the features of severe asthma a medical provider would see in younger children or adults. A specific focus on psychological issues and adherence highlights some of the challenges in the management of asthma in adolescents. Treatment of adolescents with severe asthma now includes 3 approved biologic phenotype-directed therapies. Therapies available to adults may be beneficial to adolescents with severe asthma. Research into predictors of specific treatment response by phenotypes is ongoing. Optimal treatment strategies are not yet defined and warrant further investigation.

Difficult-to-treat and severe asthma in general practice: delivery and evaluation of an educational program

Background

Asthma, a common yet complex airway disorder affecting about 11% of Australians, is well-controlled in only 54% of people with asthma. Those with difficult-to-treat and severe asthma are more likely to experience recurrent and potentially life-threatening exacerbations. It is therefore important that GPs can initiate a systematic approach for the management of patients with difficult-to-treat asthma to identify those whose condition may improve by addressing contributory factors and those who require specialist input. We therefore aimed to develop and deliver an educational program for GPs on the systematic management of patients with difficult-to-treat and severe asthma and evaluate the effectiveness of this program.

Methods

We developed an educational program on the management of difficult-to-treat and severe asthma in primary care that was delivered to GPs and other health professionals between January and June 2018. We evaluated the effectiveness of the program using a retrospective pre-test with post-survey, administered to GPs directly after program participation.

Results

Over 1000 general practice health professionals participated in the educational program, including 890 GPs of whom 226 (25%) completed the survey. Following program participation, a greater proportion of GPs identified factors they would assess in managing a patient with poor asthma control, particularly for considering the risk of future adverse outcomes (+ 51%), changes in lifestyle (+ 38%), and self-management strategies (+ 35%). GPs indicated a greater awareness of the biologic therapies that specialists could consider prescribing to their patients with severe asthma (+ 75%), of the requirements for a patient to be prescribed a biologic therapy (+ 73%) and that patients with different phenotypic characteristics can respond differently to standard therapy (+ 67%). The proportion of GPs who would refer appropriate patients to a specialist also significantly increased.

Conclusions

This study suggests that an evidence-based educational program can improve GP knowledge, confidence and intended practice in managing patients with difficult-to-treat and severe asthma.

Electronic supplementary material

The online version of this article (10.1186/s12875-019-0991-y) contains supplementary material, which is available to authorized users.

Differentiation of adult severe asthma from difficult-to-treat asthma - Outcomes of a systematic assessment protocol

BACKGROUND

Guidelines recommend a differentiation of difficult-to-treat asthma from severe asthma. However, this might be complex and to which extent this distinction is achievable in clinical practice remains unknown.

OBJECTIVE

To evaluate to which degree a systematic evaluation protocol enables a differentiation between severe versus difficult-to-treat asthma in patients in specialist care on high intensity asthma treatment, i.e. potentially severe asthma.

METHODS

All adult asthma patients seen in four respiratory clinics over one year were screened prospectively for asthma severity. Patients with difficult-to-control asthma according to ERS/ATS criteria (high-dose inhaled corticosteroids/oral corticosteroids) underwent systematic assessment to differentiate severe asthma patients from those with other causes of poor asthma control: objective confirmation of the asthma diagnosis as well as assessment of treatment barriers and comorbidities.

RESULTS

Overall, 1034 asthma patients were screened, of whom 175 (16.9%) had difficult-to-control asthma. 117 of these accepted inclusion, and completed systematic assessment. Asthma diagnosis was objectively confirmed in 88%. Sub-optimal adherence (42.5%), inhaler errors (31.5%) and unmanaged comorbidities (66.7%) were common. After primary assessment, 12% (14/117) fulfilled strict criteria for severe asthma. Moreover, 56% (66/117) were instantly classified as difficult-to-treat asthma due to poor adherence/inhaler technique. Finally, an ´overlap' group of 32% (37/117) were identified with patients being adherent and displaying correct inhaler technique, but had unmanaged comorbidities -potentially fitting into both the difficult-to-treat and severe group.

CONCLUSION

Only a minority of patients with difficult-to-control asthma were found to have severe asthma after primary systematic assessment. Nevertheless, strict categorisation of severe vs. difficult-to-treat asthma seems to pose a challenge.

Racial Disparities in Asthma-Related Health Outcomes in Children with Severe/Difficult-to-Treat Asthma

BACKGROUND

There are limited data that examine differences in asthma etiology between black and white children with severe or difficult-to-treat asthma.

OBJECTIVE

To describe demographic, clinical, and asthma-related outcomes in black and white children and examine whether differences in outcomes are explained by confounding factors in sequential multivariable models.

METHODS

Black (n = 86) and white (n = 262) children aged 6-11 years from The Epidemiology and Natural History of Asthma: Outcomes and Treatment Regimens 3-year observational study were analyzed. Baseline demographics and clinical characteristics were described for both cohorts, and outcomes at month 12 were analyzed using statistical models, sequentially adjusting for potential confounders.

RESULTS

Black children were more likely to be male (79.1% vs 66.4%; P < .05), obese (12.8% vs 1.5%; P < .001), and from a lower income stratum (USD43,400 vs 55,770; P < .001) than white children. Black children had higher geometric mean IgE levels (434.8 vs 136.8 IU/mL; P < .001), were more likely to have very poorly controlled asthma (72.1% vs 53.4%), use long-term systemic corticosteroids (30.2% vs 9.2%; P < .001), have poorer quality of life (5.5 vs 6.1; P < .001), and have an emergency department visit (27.4% vs 7.7%, P < .001) in the 3 months before month 12. Differences in asthma control and the severity of exacerbations persisted even after accounting for all confounding factors.

CONCLUSIONS

Among children with severe or difficult-to-treat asthma, asthma burden is greater in black than white children particularly related to several clinical and patient-reported outcome measures that are not explained by differences in background or clinical characteristics.

[Difficult-to-treat or severe asthma?]

Difficult to treat or severe asthma? Difficult-to-treat asthma is characterized by the need for several controllers including high dose inhaled corticosteroids to prevent it from becoming uncontrolled or which remains uncontrolled despite this therapy. Difficult-to-treat asthma can be due to inappropriate diagnosis, non-adherence to treatment, improper inhaler technique, exposition to environmental factors or co-existing conditions. Thus, difficult-to-treat asthma must be distinguished from severe asthma, which one is defined by an « intrinsic » resistance to asthma therapy. The diagnosis of difficult-to-treat asthma is a warning that should encourage to interrupt the step-up therapy process and to initiate a comprehensive approach aiming at checking the accuracy of asthma diagnosis, optimizing therapy adherence and technique, eliminating environmental factors and treating co-existing conditions. If several controllers including high dose inhaled corticosteroids are still required after this comprehensive approach, then asthma is called severe asthma.

Asthma Exacerbations and Triggers in Children in TENOR: Impact on Quality of Life

BACKGROUND

Data examining associations between asthma exacerbations, triggers, and asthma-related quality of life (QOL) in children with severe/difficult-to-treat asthma are unavailable.

OBJECTIVE

To evaluate real-world data on relationships between asthma exacerbations, triggers, and QOL in children using data from TENOR (The Epidemiology and Natural History of Asthma Outcomes and Treatment Regimens), a 3-year observational study of patients with severe/difficult-to-treat asthma, including those aged 6 to 12 years.

METHODS

QOL was examined using the Pediatric Asthma Quality of Life Questionnaire (PAQLQ) and defined exacerbations hierarchically (descending order of severity): hospitalization, emergency department visit, steroid burst, no exacerbation, using the highest value from months 6 and 12. One-way ANOVA was used to test for differences in PAQLQ domain scores at month 12 across exacerbation severity, total number of asthma exacerbations, and number of baseline asthma triggers. Mantel-Haenszel chi-square test was used to test the association between the number of triggers and exacerbation hierarchy.

RESULTS

Greater severity of asthma exacerbations was associated with significantly (P < .001) lower mean PAQLQ domain scores, indicating poorer QOL. A higher number of asthma exacerbations was associated with significantly (P < .001) lower mean PAQLQ domain scores. PAQLQ scores were significantly lower with higher numbers of baseline triggers. Higher baseline number of asthma triggers was associated with greater severity (P = .05) and number of asthma exacerbations (P < .001).

CONCLUSIONS

A higher number of asthma triggers at baseline was associated with greater asthma severity and number of asthma exacerbations and lower QOL in children with severe/difficult-to-treat asthma.

Impact of asthma exacerbations and asthma triggers on asthma-related quality of life in patients with severe or difficult-to-treat asthma

BACKGROUND

Few data are available that evaluate the relationship among asthma exacerbations, asthma triggers, and asthma-related quality of life (QoL).

OBJECTIVE

To evaluate the impact of asthma exacerbations and asthma triggers on QoL.

METHODS

Patients with severe or difficult-to-treat asthma, ages ≥ 13 years (n = 2679) from the TENOR (The Epidemiology and Natural History of Asthma: Outcomes and Treatment Regimens) 3-year observational study were included. Exacerbations were defined hierarchically in descending order of severity (hospitalization, emergency department [ED] visit, steroid burst, no exacerbation) by using data from months 6 and 12. The total number (frequency) of exacerbations was assessed. Asthma-related QoL was measured at month 12 by using the Mini-Asthma QoL Questionnaire (Mini-AQLQ); self-reported asthma triggers were collected at baseline and annually. We used 1-way ANOVA to test for differences in Mini-AQLQ domain scores across asthma exacerbation severity, the total number of asthma exacerbations, and the number of asthma triggers.

RESULTS

A significant decrease (P < .001) in Mini-AQLQ domain scores was seen with increasing severity of asthma exacerbation (no exacerbation, steroid burst, ED visit, and hospitalization); symptom (5.5, 4.8, 4.3, and 4.2), activity (5.8, 5.2, 4.6, and 4.4), emotional (5.6, 5.0, 4.4, and 4.2), exposure (5.0, 4.5, 4.0, and 3.9); and overall (5.5, 4.9, 4.3, and 4.1). Increasing exacerbation frequency and the number of baseline asthma triggers also were associated with significant decreases in Mini-AQLQ domain scores. An increasing number of asthma triggers were associated with an increase in severity and frequency of exacerbations.

CONCLUSION

Avoidance of asthma triggers may reduce exacerbation rates and improve asthma-related QoL in patients with severe or difficult-to-treat asthma. Interventional studies are warranted to further explore these outcomes.