Diagnosis of severe asthma

The Prevalence of Bronchodilator Responsiveness "Asthma" Among Adult Indigenous Australians Referred for Lung Function Testing in the Top End Northern Territory of Australia

Background

Among Indigenous Australians, studies examining the clinical significance of airway bronchodilator responsiveness (BDR) are limited. In this retrospective study, we examined the nature of underlying lung disease in adult Indigenous patients with BDR referred for lung function testing (LFT) in the Top End Health Service region of the Northern Territory of Australia.

Methods

Presence or absence of BDR as per usual (FVC or FEV₁ change pre to post ≥12% and ≥0.2L) and updated (2021 ">10% predicted) ATS/ERS criteria among Indigenous and non-Indigenous Australians was determined. The radiological findings in the Indigenous study participants with and without BDR were next assessed for the presence of underlying chronic airway/lung disease.

Results

We found that 123/742 (17%) Indigenous and 578/4579 (13%) non-Indigenous patients had a significant BDR. Indigenous patients with BDR were younger (mean difference 7 years), with a greater proportion of females (52 vs 32%), underweight (15 vs 4%) and current smokers (52 vs 25%). Indigenous patients with BDR displayed lower LFT values, and a higher proportion exhibited FVC BDR compared to non-Indigenous (34 vs 20%). Almost half (46%) of Indigenous patients with BDR had evidence of COPD and/or bronchiectasis on radiology. Adjusting for the presence of radiologic or spirometric evidence of COPD, the presence of BDR was similar between Indigenous and non-Indigenous patients (5-8 vs 7-11%), irrespective of which BDR criteria was used.

Conclusion

BDR was higher overall among Indigenous in comparison to non-Indigenous patients; however, a significant proportion of Indigenous patients demonstrating BDR had evidence of underlying COPD/bronchiectasis. This study highlights that although presence of BDR among Indigenous people may indicate asthma, it may also be observed among patients with COPD/bronchiectasis or could represent asthma/COPD/bronchiectasis overlap. Hence, a combination of clinical history, LFT and radiology should be considered for precise diagnosis of lung disease in this population.

Blood tryptase and thymic stromal lymphopoietin levels predict the risk of exacerbation in severe asthma

Some patients with severe asthma experience exacerbations despite receiving multiple therapy. The risk of exacerbation and heterogeneous response to treatment may be associated with specific inflammatory molecules that are responsive or resistant to corticosteroids. We aimed to identify the independent factors predictive for the future risk of exacerbation in patients with severe asthma. In this multi-center prospective observational study, 132 patients with severe asthma were enrolled and divided into exacerbation (n = 52) and non-exacerbation (n = 80) groups on the basis of exacerbation rate after a 1-year follow-up period. We found that previous history of severe-to-serious exacerbation, baseline blood eosinophil counts (≥ 291cells/μL), and serum tryptase (≤ 1448 pg/mL) and thrymic stromal lymphopoietin (TSLP) levels (≥ 25 pg/mL) independently predicted the future development of exacerbation with adjusted odds ratios (AOR) of 3.27, 6.04, 2.53 and 8.67, respectively. Notably, the patients with high blood eosinophil counts and low tryptase levels were likely to have more exacerbations than those with low blood eosinophil counts and high tryptase levels (AOR 16.9). TSLP potentially played the pathogenic role across different asthma phenotypes. TSLP and tryptase levels may be implicated in steroid resistance and responsiveness in the asthma inflammatory process. High blood eosinophil counts and low serum tryptase levels predict a high probability of future asthma exacerbation.

Cumulative dispensing of high oral corticosteroid doses for treating asthma in Australia

OBJECTIVE

To estimate the level of dispensing of oral corticosteroids (OCS) for managing asthma in Australia, with a particular focus on the cumulative dispensing of doses associated with long term toxicity (≥ 1000 mg prednisolone-equivalent).

DESIGN

Retrospective cohort study; analysis of 10% random sample of Pharmaceutical Benefits Scheme (PBS) dispensing data.

PARTICIPANTS, SETTING

People aged 12 years or more treated for asthma during 2014-2018, according to dispensing of controller inhaled corticosteroids (ICS).

MAIN OUTCOME MEASURES

Number of people dispensed OCS for managing asthma during 2014-2018; proportion who were cumulatively dispensed at least 1000 mg prednisolone-equivalent. The secondary outcome was the number of people dispensed at least 1000 mg prednisolone-equivalent during 2018, stratified by inhaler controller dose and use.

RESULTS

124 011 people had been dispensed at least two prescriptions of ICS during 2014-2018 and met the study definition for asthma, of whom 64 112 (51.7%) had also been dispensed OCS, including 34 580 (27.9% of the asthma group) cumulatively dispensed 1000 mg prednisolone-equivalent or more. Of 138 073 people dispensed OCS at this level, 68 077 (49%) were patients with airway diseases. Dispensing of diabetes and osteoporosis medications was more common for people cumulatively dispensed 1000 mg prednisolone-equivalent or more. During 2018, 4633 people with asthma using high dose ICS controllers were dispensed 1000 mg prednisolone-equivalent or more, for 2316 of whom (50%) controller use was inadequate.

CONCLUSIONS

Cumulative exposure to OCS in Australia reaches levels associated with toxicity in one-quarter of patients with asthma using ICS. Cumulative dispensing of potentially toxic OCS amounts often accompanies inadequate inhaler controller dispensing. Better approaches are needed to improve adherence to controller therapy, improve outcomes for people with asthma, and to minimise the use and toxicity of OCS.

Systematic Assessment for Difficult and Severe Asthma Improves Outcomes and Halves Oral Corticosteroid Burden Independent of Monoclonal Biologic Use

BACKGROUND

Guidelines endorse systematic assessment for severe asthma, with data indicating benefit across multiple outcome domains.

OBJECTIVE

We examined which patients respond to systematic assessment and whether oral corticosteroid burden can be decreased independent of monoclonal biologic use.

METHODS

Specialist-referred patients are assessed systematically for difficult asthma at our center. We undertook a responder analysis for improvements in the domains of symptom control, quality of life, exacerbations, and airflow obstruction, assessed 6 months after initial assessment. Multivariate analyses were performed for each domain to identify predictors of response. Changes in oral corticosteroid burden were also measured, stratified by monoclonal biologics commenced during assessment.

RESULTS

Among 161 patients assessed systematically, 64% had a reduction in exacerbations, 54% achieved minimum clinically important differences for both symptom control and quality of life, and 40% increased their forced expiratory volume in 1 second by ≥100 mL. Altogether, 87% of patients with asthma improved in at least 1 domain. The most consistent predictor of response across domains was poorer baseline asthma status. There was a substantial reduction in mean chronic oral corticosteroid dose (11-5 mg, n = 46, P < .001), even after excluding 7 patients commenced on monoclonal biologics (11-5.6 mg, n = 39, P < .001).

CONCLUSIONS

Almost 90% of patients undergoing systematic assessment for difficult asthma improve significantly in at least 1 key asthma outcome, with few reliable predictors of response. The halving of oral corticosteroid burden during systematic assessment is independent of, and comparable in magnitude with, that achieved by monoclonal biologics.

Approaches to the assessment of severe asthma: barriers and strategies

Asthma is a chronic condition with great variability. It is characterized by intermittent episodes of wheeze, cough, chest tightness, dyspnea and backed by variable airflow limitation, airway inflammation and airway hyper-responsiveness. Asthma severity varies uniquely between individuals and may change over time. Stratification of asthma severity is an integral part of asthma management linking appropriate treatment to establish asthma control. Precision assessment of severe asthma is crucial for monitoring the health of people with this disease. The literature suggests multiple factors that impede the assessment of severe asthma, these can be grouped into health care professional, patient and organizational related barriers. These barriers do not exist in isolation but interact and influence one another. Recognition of these barriers is necessary to promote precision in the assessment and management of severe asthma in the era of targeted therapy. In this review, we discuss the current knowledge of the barriers that impede assessment in severe asthma and recommend potential strategies for overcoming these barriers. We highlight the relevance of multidimensional assessment as an ideal approach to the assessment and management of severe asthma.

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.

Two Sides of the Same Coin?-Treatment of Chronic Asthma in Children and Adults

Globally, asthma is one of the most common chronic conditions that affect individuals of all ages. When poorly controlled, it negatively impacts patient's ability to enjoy life and work. At the population level, effective use of recommended strategies in children and adults can reduce symptom burden, improve quality of life and significantly reduce the risk of exacerbation, decline of lung function and asthma-related death. Inhaled corticosteroid as the initial maintenance therapy, ideally started within 2 years of symptom onset, is highly effective in both children and adults and across various degrees of asthma severity. If asthma is not controlled, the choice of subsequent add-on therapies differs between children and adults. Evidence supporting pharmacological approach to asthma management, especially for those with more severe disease, is more robust in adults compared to children. This is, in part, due to various challenges in the diagnosis of asthma, in the recruitment into clinical trials and in the lack of objective outcomes in children, especially those in the preschool age group. Nevertheless, where evidence is emerging for younger children, it seems to mirror the observations in adults. Clinicians need to develop strategies to implement guideline-based recommendations while taking into consideration individual variations in asthma clinical phenotypes, pathophysiology and treatment responses at different ages.