Characterizing the severe asthma population in the United States: claims-based analysis of three treatment cohorts in the year prior to treatment escalation

A systematic literature review of burden of illness in adults with uncontrolled moderate/severe asthma

BACKGROUND

There are limited published data on the burden of moderate/severe uncontrolled asthma.

METHODS

We conducted a systematic literature review to better understand the impact of moderate-to-severe asthma in the US, the UK, Germany, France, Italy, Spain, Canada, Japan, and Australia in terms of prevalence, clinical measures, health-related quality of life (HRQoL) and economic burden, for patients whose asthma is uncontrolled despite inhaled corticosteroid/long-acting β₂-agonist (ICS/LABA) therapy.

RESULTS

The prevalence of uncontrolled asthma among patients with moderate/severe disease varied but was as high as 100% in some subgroups. Patients with uncontrolled asthma generally had poor lung function (mean/median pre-bronchodilator forced expiratory volume in 1 second [FEV₁]: 1.69-2.45 L; mean/median pre-bronchodilator percent predicted FEV₁: 57.2-79.7). There was also a substantial but variable exacerbation burden associated with uncontrolled asthma, with the annualised rate of exacerbations ranging from 1.30 to 7.30 when considering various patient subgroups. Furthermore, the annualised rate of severe exacerbations ranged from 1.66 to 3.60. The HRQoL burden measured using disease-specific and generic instruments consistently demonstrated substantial impairment of HRQoL for those with uncontrolled asthma; Asthma Quality of Life Questionnaire scores ranged from 3.00 to 5.20, whilst EurQol-5 Dimensions index scores ranged from 0.53 to 0.59. Direct, indirect and total costs together with consumption of other healthcare resources associated with managing uncontrolled asthma were also substantial in the population studied; no caregiver burden was identified.

CONCLUSIONS

Our findings suggest that significant unmet needs exist for patients with uncontrolled asthma despite the availability of ICS/LABA therapy. Novel treatments are needed to help reduce the burden to patients, healthcare systems and society.

Exacerbations in US Severe Asthma: Incidence, Characteristics, Predictors, and Effects of Biologic Treatments

BACKGROUND

Patients with severe asthma (SA) have a heightened risk of exacerbations, including hospitalization. The real-world, specialist-verified incidence and characteristics of exacerbations among patients with SA in the United States (US) have not been described.

OBJECTIVE

To describe the real-world incidence, characteristics, and predictors of exacerbations among patients with SA in the US.

METHODS

CHRONICLE is an ongoing observational study of specialist-treated US adults with SA receiving biologic treatment or maintenance systemic corticosteroids (SCS), or uncontrolled by high-dosage inhaled corticosteroids with additional controllers. For patients enrolled February 2018 to February 2020, annualized rates and characteristics of exacerbation-related events were summarized by treatment category for 12 months before enrollment and after enrollment through the latest data collection. Results were further analyzed for subgroups of interest.

RESULTS

Among 1884 enrolled patients, 53.5% and 12.3% experienced an exacerbation and asthma hospitalization, respectively (0.81 and 0.14 per person-year). Of all exacerbations, 36%, 9%, and 15% required an unscheduled healthcare provider visit, emergency department visit without hospitalization, and hospitalization, respectively. Among patients not receiving biologics or SCS, higher blood eosinophil count, higher fractional exhaled nitric oxide, and lower total immunoglobulin E level were associated with higher exacerbation rates. Exacerbation rates decreased after starting or switching biologics (n = 1299). Multivariate analyses of enrolled patients showed prior-year exacerbations/hospitalizations, lack of asthma control, and geographic region also predicted event risk.

CONCLUSION

In this real-world cohort of specialist-treated US adults with SA, there was a substantial burden of exacerbations and associated healthcare resource utilization. Patients receiving biologics had a lower exacerbation burden.

Characteristics of Specialist-Diagnosed Asthma-COPD Overlap in Severe Asthma: Observations from the Korean Severe Asthma Registry (KoSAR)

BACKGROUND

While the clinical characteristics and outcomes of asthma-chronic obstructive pulmonary disease (COPD) overlap (ACO) have been frequently compared with those of COPD or asthma, the prevalence and features of ACO in patients with severe asthma are unclear.

OBJECTIVES

Evaluation of the prevalence and clinical features of ACO using the Korean severe asthma registry.

METHODS

At the time of registration, ACO was determined in patients with severe asthma by attending specialists. Patients were classified into ACO and non-ACO groups, and the demographic and clinical characteristics of these two groups were compared.

RESULTS

Of 482 patients with severe asthma, 23.7% had ACO. Patients in the ACO group were more likely to be male (P < .001), older (P < .001), and ex- or current smokers (P < .001) compared with those in the non-ACO group. Patients in the ACO group had lower mean forced expiratory volume in 1 second (P < .001) and blood eosinophil percentage (P = .006), but higher blood neutrophil percentage (P = .027) than those in the non-ACO group. The ACO group used more inhaled long-acting muscarinic antagonist (P < .001), methylxanthine (P = .001), or sustained systemic corticosteroid (P = .002). In addition, unscheduled emergency department visits due to exacerbation were more frequent in the ACO group (P = .006).

CONCLUSION

Among patients with severe asthma, those with ACO were older, predominantly male, and were more likely to have a smoking history than those with asthma only. Patients with ACO used more systemic corticosteroid and had more frequent exacerbations related to emergency department visits than those with severe asthma only.

Bronchiectasis and increased mortality in patients with corticosteroid-dependent severe asthma: a nationwide population study

BACKGROUND

Long-term corticosteroid (CS) use is associated with increased mortality in patients with asthma, and comorbid bronchiectasis is also associated with frequent asthma exacerbation and increased healthcare use. However, there is limited information on whether bronchiectasis further increases mortality in patients with CS-dependent asthma. This study examined the impact of bronchiectasis on mortality in patients with CS-dependent asthma.

METHODS

A retrospective cohort of patients with CS-dependent asthma ⩾18 years old was established using records from the Korean National Health Insurance Service database from 2005 to 2015. Patients with CS-dependent asthma with and without bronchiectasis were matched by age, sex, type of insurance, and Charlson comorbidity index. We evaluated the hazard ratio (HR) for all-cause mortality in patients with bronchiectasis compared with those without bronchiectasis.

RESULTS

The study cohort included 754 patients with CS-dependent asthma with bronchiectasis and 3016 patients with CS-dependent asthma without bronchiectasis. Patients with CS-dependent asthma with bronchiectasis had a higher all-cause mortality than those without bronchiectasis (8429/100,000 versus 6962/100,000 person-years, p < 0.001). The adjusted HR for mortality in patients with CS-dependent asthma with bronchiectasis relative to those without bronchiectasis was 1.33 (95% confidence interval, 1.18-1.50), and the association was primarily significant for respiratory diseases (subdistribution HR = 1.65, 95% confidence interval, 1.42-1.92).

CONCLUSIONS

Bronchiectasis further increases all-cause mortality in patients with CS-dependent asthma, a trend that was especially associated with respiratory diseases including chronic obstructive pulmonary disease. Strategies to improve treatment outcomes in patients with CS-dependent asthma with bronchiectasis are urgently needed to improve long-term survival.The reviews of this paper are available via the supplemental material section.

Increased mortality in patients with corticosteroid-dependent asthma: a nationwide population-based study

INTRODUCTION

Chronic systemic corticosteroid (CS) therapy is associated with an increased risk of mortality in patients with many chronic diseases. However, it has not been elucidated whether chronic systemic CS therapy is associated with increased mortality in patients with asthma. The aim of this study was to determine the effects of chronic systemic CS therapy on long-term mortality in adult patients with asthma.

METHODS

A population-based matched cohort study of males and females aged ≥18 years with asthma was performed using the Korean National Health Insurance Service database from 2005 to 2015. Hazard ratio (HR) with 95% confidence interval for all-cause mortality among patients in the CS-dependent cohort (CS use ≥6 months during baseline period) relative to those in the CS-independent cohort (CS use <6 months during baseline period) was evaluated.

RESULTS

The baseline cohort included 466 941 patients with asthma, of whom 8334 were CS-dependent and 458 607 were CS-independent. After 1:1 matching, 8334 subjects with CS-independent asthma were identified. The HR of mortality associated with CS-dependent asthma relative to CS-independent asthma was 2.17 (95% CI 2.04-2.31). In patients receiving low-dose CS, the HR was 1.84 (95% CI 1.69-2.00); in patients receiving high-dose CS, the HR was 2.56 (95% CI 2.35-2.80).

CONCLUSIONS

In this real-world, clinical practice, observational study, chronic use of systemic CS was associated with increased risk of mortality in patients with asthma, with a significant dose-response relationship between systemic CS use and long-term mortality.

Development and initial validation of the Asthma Severity Scoring System (ASSESS)

BACKGROUND

Tools for quantification of asthma severity are limited.

OBJECTIVE

We sought to develop a continuous measure of asthma severity, the Asthma Severity Scoring System (ASSESS), for adolescents and adults, incorporating domains of asthma control, lung function, medications, and exacerbations.

METHODS

Baseline and 36-month longitudinal data from participants in phase 3 of the Severe Asthma Research Program (NCT01606826) were used. Scale properties, responsiveness, and a minimally important difference were determined. External replication was performed in participants enrolled in the Severe Asthma Research Program phase 1/2. The utility of ASSESS for detecting treatment response was explored in participants undergoing corticosteroid responsiveness testing with intramuscular triamcinolone and participants receiving biologics.

RESULTS

ASSESS scores ranged from 0 to 20 (8.78 ± 3.9; greater scores reflect worse severity) and differed among 5 phenotypic groups. Measurement properties were acceptable. ASSESS was responsive to changes in quality of life with a minimally important difference of 2, with good specificity for outcomes of asthma improvement and worsening but poor sensitivity. Replication analyses yielded similar results, with a 2-point decrease (improvement) associated with improvements in quality of life. Participants with a 2-point or greater decrease (improvement) in ASSESS scores also had greater improvement in lung function and asthma control after triamcinolone, but these differences were limited to phenotypic clusters 3, 4, and 5. Participants treated with biologics also had a 2-point or greater decrease (improvement) in ASSESS scores overall.

CONCLUSIONS

The ASSESS tool is an objective measure that might be useful in epidemiologic and clinical research studies for quantification of treatment response in individual patients and phenotypic groups. However, validation studies are warranted.

Asthma severity in four countries of Latin America

BACKGROUND

In Latin America, there is scarce information about severe asthma (SA) according to the ERS/ATS 2014 criteria. This study aimed to compare the demographic, socio, clinical characteristics, treatment, and use of healthcare resources between SA and non-severe asthma (NSA) patients in Argentina, Colombia, Chile and Mexico.

METHODS

A cross-sectional study was conducted including 594 asthma patients from outpatient specialized sites. A descriptive analysis was performed comparing SA patients and NSA. Chi-square and Mann Whitney tests were used to assess associations between asthma severity and outcome variables.

RESULTS

Using ERS/ATS 2014 criteria, 31.0% of the patients were identified as SA. SA patients were older at diagnosis (mean age 31.64 years vs 24.71 years, p < 0.001) and had higher proportion of uncontrolled asthma than the NSA patients (64.1% vs 53.2%, p < 0.001). SA patients reported a significantly higher proportion of both hospital admission and emergency room (ER) visits due to asthma in the last year, compared with NSA patients, 8.7% vs. 3.7% (p = 0.011) and 37.0% vs. 21.7% (p < 0.001), respectively.

CONCLUSIONS

SA patients were older, had greater proportions in some comorbidities and experienced increased healthcare utilization. Also, our results showed that even in patients using the last steps of treatment (GINA step 4 or 5), there was still a higher proportion of uncontrolled disease.

A retrospective cohort study evaluating healthcare resource utilization in patients with asthma in Japan

Although the global economic burden of asthma is well described, detailed data regarding Asia, particularly for Japan, are relatively scarce. This retrospective study aims to fill this evidence gap by evaluating asthma-associated healthcare resource utilization (HCRU) and economic burden in Japanese patients aged ≥16 years, identified using anonymized patient data from the Japan Medical Data Center (JMDC) database from April 2009 to March 2015. Asthma severity was classified according to asthma treatment guidelines from the Japanese Society of Allergology. HCRU was calculated based on hospitalizations, emergency room visits, outpatient visits, and prescriptions. Incidence rate ratios (IRRs) for HCRU and per-patient-per-year direct costs were reported. In addition, differences across HCRU and cost variables for severe versus non-severe asthma patients were also compared. Of 541,434 asthma cases identified from the JMDC database during the study period, 54,433 patients who met the inclusion criteria were included in this analysis. HCRU and costs were heavily concentrated within severe asthma, a subgroup comprising 12.7% of total study population. Moreover, patients with severe asthma had significantly higher all-cause hospitalizations, outpatient visits, outpatient prescriptions (IRR [95% CI], 1.60 [1.46–1.76]; 1.43 [1.41–1.45]; 1.24 [1.22–1.25], respectively), and total medical costs (mean ± SD costs, US$ 4345 ± 11,104 versus US$ 1528 ± 3989, P < 0.001 (t-test); US$ 1 = 110 JPY) compared with those with non-severe asthma. The burden of asthma is significantly and disproportionately concentrated in Japanese severe asthma patients, suggesting clinical failure to achieve adequate disease control. This study highlights the unmet needs for severe asthma in Japan and provides a catalyst for important dialogues in advancing public health.

Systematic literature review of the clinical, humanistic, and economic burden associated with asthma uncontrolled by GINA Steps 4 or 5 treatment

OBJECTIVE

This study sought to characterize the epidemiologic, clinical, humanistic, and economic burden of patients with asthma uncontrolled by GINA Steps 4 or 5 treatment (severe, uncontrolled asthma [SUA]).

METHODS

A systematic literature review adhering to PRISMA guidelines was performed. Relevant publications were searched for in MEDLINE and EMBASE from January 2004 to September 2016 and in a conference proceedings database from January 2012 to October 2016. Studies were screened using the Population, Intervention, Comparator, Outcomes, Study Design, and Time (PICOS-T) framework. Studies of SUA with observational (prospective and retrospective), randomized, or nonrandomized study designs; adult patient populations; sample sizes ≥20 patients; epidemiologic or clinical outcomes, patient-reported outcomes (PROs), or economic outcomes were included. For our analysis, SUA was defined as inadequate control of asthma, despite the use of medium- to high-dosage inhaled corticosteroids and at least one additional treatment.

RESULTS

A total of 195 articles reporting unique study populations were included. Prevalence of SUA was as great as 87.4% for patients with severe asthma, although values varied depending on the criteria used to define asthma control. Compared with patients with severe asthma who were controlled, patients with SUA experienced more symptoms, night-time awakenings, rescue medication use, and worse PROs. SUA-associated costs were 3-times greater than costs for patients with severe, controlled disease.

CONCLUSION

Despite the availability of approved asthma treatments, this literature analysis confirms that SUA poses a substantial epidemiologic, clinical, humanistic, and economic burden. Published data are limited for certain aspects of SUA, highlighting a need for further research.

Guiding principles for use of newer biologics and bronchial thermoplasty for patients with severe asthma

BACKGROUND

Severe asthma poses significant disease-related and economic burdens in the United States. Challenges in practice include how to define "severe asthma" for a given patient, knowing which are the right tests to perform and when, and having a better understanding of a patient's asthma phenotype. Furthermore, current guidelines do not address a clear, practical approach to treatment that is based on a patient's asthma phenotype.

OBJECTIVE

To develop a consensus on the definition of severe asthma, the role of biomarkers and phenotyping severe asthma, and the use of newer biologic therapies and bronchial thermoplasty to help guide practicing clinicians.

METHODS

A roundtable meeting was convened with a panel of severe asthma experts to discuss areas in practice that are not adequately addressed by current guidelines, specifically phenotype-guided treatment.

RESULTS

We describe a consensus on the definition of severe asthma, asthma phenotyping with the use of available biomarkers, and guiding principles for newer biologic therapies and bronchial thermoplasty.

CONCLUSION

To optimize therapy and improve outcomes such as daily symptoms, quality of life, exacerbations, and hospitalizations, a clear picture of a patient's asthma phenotype is needed to guide therapy. Determining asthma phenotypes is the foundation of precision medicine for this persistent, often difficult-to-treat disease.

Oral corticosteroid exposure and adverse effects in asthmatic patients

BACKGROUND

Significant adverse effects (AEs) have been associated with continuous exposure to oral corticosteroids (OCSs). The potential association with intermittent exposure is unknown.

OBJECTIVE

We sought to assess the association between OCSs and AEs based on the number of OCS prescriptions.

METHODS

This was a retrospective cohort study of asthmatic patients 18 years and older in the 2000-2014 MarketScan data set. Propensity score matching was used at baseline (12 months before the index date: first OCS use). Logistic regression was used to examine the association between OCSs and new incident AEs (either combined or individual) controlling for covariates. Follow-up continued for 24 months minimum and 10 years maximum after the index date.

RESULTS

There were 72,063 and 156,373 subjects in the OCS and no OCS cohorts, respectively. Subjects taking 4 or more OCS (1-3) prescriptions within the year had 1.29 (1.04) times the odds of experiencing a new AE within the year. Each year of exposure to 4 or more OCS prescriptions (current and past) resulted in 1.20 times the odds of having an AE in the current year. Exposure to 4 or more prescriptions was associated with significantly greater odds of AEs for osteoporosis, hypertension, obesity, type 2 diabetes, gastrointestinal ulcers/bleeds, fractures, and cataracts (odds, 1.21-1.44 depending on the AE).

CONCLUSION

Although previous research has documented the deleterious effect of continuous OCS exposure in patients with severe asthma, our results suggest that each OCS prescription might result in a cumulative burden on current and future health regardless of dose and duration. OCS-sparing strategies are extremely important to improve patient outcomes.

Burden of systemic glucocorticoid-related complications in severe asthma

OBJECTIVES

Although systemic glucocorticoids (SGCs) are efficacious, their chronic use is associated with a range of complications. Yet limited data are available about the risks following chronic use in patients with severe asthma, who are at risk of long-term SGC-related complications. This study was carried out to investigate the risks of developing SGC-related complications, and to quantify the associated healthcare resource utilization and costs for patients with severe asthma in the United States.

METHODS

This was a longitudinal, open-cohort, observational study. Medicaid claims data (1997-2013) for patients ≥12 years old with ≥2 asthma diagnoses were used. A total of 26,987 SGC non-users were identified for inclusion in the study, alongside 3628 SGC users with ≥6 months' continuous SGC use.

RESULTS

Multivariate generalized estimating equation models were used to estimate the adjusted risk of developing SGC-related complications, and to quantify the associated healthcare resource utilization and costs. This analysis compared SGC users with SGC non-users, and found that SGC users had an increased likelihood of developing complications. A significant dose-response relationship was demonstrated between chronic SGC use and risk of developing any complications (odds ratios for low, medium, and high SGC exposure were 2.03 [p = .0511], 2.85 [p < .0001], and 3.64 [p < .0001], respectively, vs. SGC non-users). The increased likelihood of SGC-related complications translated into estimated annual healthcare costs for SGC users of $2712 to $8560 above those of SGC non-users. A key limitation of this study is the disparity in age between the SGC users and the SGC non-users; however, age was included as a confounding factor in the analysis.

CONCLUSIONS

These findings confirm the risk associated with chronic use of SGCs, irrespective of dose level, and highlight the need for new SGC-sparing treatment strategies for patients with severe asthma.