Subacute lack of asthma control and acute asthma exacerbation history as predictors of subsequent acute asthma exacerbations: evidence from managed care data

Barriers and determinants of asthma control in children and adolescents in Africa: a systematic review

OBJECTIVE

To identify reasons for poor asthma control in African children and adolescents.

DESIGN

Systematic review DATA SOURCES: PubMed, Scopus, CINHAL, PsycINFO, MEDLINE and Web of Science databases were systematically searched up to 31 May 2020. Hand searching was done on Sabinet, African Journal online and Google Scholar.

ELIGIBILITY CRITERIA

Studies identifying barriers to asthma control, where asthma control was assessed by the validated Asthma Control Test/Child Asthma Control Test and/or Asthma Control Questionnaire were included.

DATA EXTRACTION AND SYNTHESIS

Two reviewers independently selected studies for inclusion with disagreements resolved by a research team discussion, including a third reviewer. Data were extracted using the Cochrane Effective Practice and Organization of Care data collection form. The quality of the included studies was assessed using the modified Newcastle-Ottawa quality assessment scale. Identified barriers were reported in a thematic narrative synthesis.

PRIMARY OUTCOMES

Poorly controlled asthma and associated factors.

RESULTS

From 914 records, three studies conducted between 2014 and 2019 in Nigeria, Uganda and South Africa met the inclusion criteria. A total of 883 children aged 4-19 years were analysed. Older age, concurrent allergy and city-dwelling significantly impacted asthma control. Few children with asthma symptoms in the community had ever used inhaled corticosteroids (6.7%) and identified reasons included lack of asthma diagnosis (38.8%) and no prescribed treatment (47.6%).

CONCLUSION

Asthma control in African children is impacted by age, allergy, urbanisation and lack of access to asthma diagnosis and treatment. More studies focusing on identifying barriers to asthma control in Africa are needed.

PROSPERO

Registration no: CRD42020196755).

Association of Metformin Initiation and Risk of Asthma Exacerbation. A Claims-based Cohort Study

Rationale: Diabetes and metabolic syndrome have been associated with worsened asthma control. Metformin improves insulin resistance and metabolic function. Experimental studies suggest that metformin may improve pathologic features of asthma, but evidence of clinical benefit is limited.Objectives: To determine if treatment with metformin in a cohort of individuals with asthma and diabetes is associated with lower risk of asthma exacerbation.Methods: A 6-year retrospective cohort of individuals over age 18 with asthma and diabetes was assembled from a national administrative claims database. New users of metformin were matched to nonusers by propensity score on the basis of demographic, comorbidity, and medication-use characteristics. An exacerbation was defined as an asthma-related hospitalization, emergency department visit, or filling of a systemic corticosteroid prescription within 14 days of an asthma-related ambulatory visit. Cox proportional hazards estimated the change in hazard of asthma exacerbation associated with metformin initiation.Results: In a cohort of 23,920 individuals with asthma and diabetes, metformin initiation was associated with lower hazard of asthma exacerbation (hazard ratio [HR], 0.92; 95% confidence interval [CI], 0.86-0.98), driven by lower hazards of asthma-related emergency department visits (HR, 0.81; 95% CI, 0.74-0.88) and hospitalization (HR, 0.67; 95% CI, 0.50-0.91), without differences in corticosteroid use (HR, 0.96; 95% CI, 0.86-1.03).Conclusions: In an administrative cohort of individuals with asthma and diabetes, metformin initiation was associated with a lower hazard of asthma-related emergency department visits and hospitalizations. These findings suggest a possible benefit of metformin in more severe asthma exacerbations. Investigation within cohorts with more detailed participant characterization is necessary.

Risk of exacerbation of pulmonary comorbidities in patients with rheumatoid arthritis after initiation of abatacept versus TNF inhibitors: A cohort study

BACKGROUND

Biologic agents may pose a potential risk for exacerbations of pulmonary comorbidities in rheumatoid arthritis (RA) patients.

METHODS

Using U.S. Medicare and Truven MarketScan databases, we identified three cohorts of RA patients with interstitial lung disease (ILD), chronic obstructive pulmonary disease (COPD), or asthma who initiated abatacept or a TNF inhibitor (TNFi). The primary outcome was a composite exacerbation of individual pulmonary comorbidities based on inpatient or emergency department (ED) visits due to exacerbation of the given pulmonary comorbidity. To adjust for >60 baseline confounders, we used propensity-score fine stratification (PSS) and weighting. Negative binomial regression model estimated a cohort-specific incidence rate ratio (IRR) and 95% confidence interval (CI) of the primary outcome per database, comparing abatacept versus TNFi. Database-specific IRRs were combined using a random-effects meta-analysis.

RESULTS

We identified 3,295 ILD, 7,161 COPD, and 5,613 asthma patients with RA who initiated either abatacept or a TNFi. IR of composite exacerbation was high in all three pulmonary cohorts but highest in COPD cohort (3.59-11.80 per 100 person-years in ILD, 20.68-34.97 in COPD, and 4.66-13.78 in asthma). After PSS weighting, the combined IRR (95%CI) in abatacept initiators versus TNFi initiators was 0.44 (0.18-1.09) for ILD exacerbation, 0.91 (0.80-1.03) for COPD exacerbation, and 0.81 (0.54-1.22) for asthma exacerbation.

CONCLUSION

Among patients with RA and pulmonary comorbidities, exacerbations requiring inpatient or ED visits occurred frequently after initiating abatacept or TNFi. Overall, we found no significant difference in the risk of ILD, COPD or asthma exacerbation between abatacept and TNFi initiators, but precision of our estimates is limited.

Multi-Method Molecular Characterisation of Human Dust-Mite-associated Allergic Asthma

Asthma is a chronic inflammatory disorder of the airways. Disease presentation varies greatly in terms of cause, development, severity, and response to medication, and thus the condition has been subdivided into a number of asthma phenotypes. There is still an unmet need for the identification of phenotype-specific markers and accompanying molecular tools that facilitate the classification of asthma phenotype. To this end, we utilised a range of molecular tools to characterise a well-defined group of female adults with poorly controlled atopic asthma associated with house dust mite (HDM) allergy, relative to non-asthmatic control subjects. Circulating messenger RNA (mRNA) and microRNA (miRNA) were sequenced and quantified, and a differential expression analysis of the two RNA populations performed to determine how gene expression and regulation varied in the disease state. Further, a number of circulating proteins (IL-4, 5, 10, 13, 17 A, Eotaxin, GM-CSF, IFNy, MCP-1, TARC, TNFα, Total IgE, and Endotoxin) were quantified to determine whether the protein profiles differed significantly dependent on disease state. Finally, we utilised a previously published assessment of the circulating “blood microbiome” performed using 16S rRNA amplification and sequencing. Asthmatic subjects displayed a range of significant alterations to circulating gene expression and regulation, relative to healthy control subjects, that may influence systemic immune activity. Notably, several circulating mRNAs were detected in just the asthma group or just in the control group, and many more were observed to be expressed at significantly different levels in the asthma group compared to the control group. Proteomic analysis revealed increased levels of inflammatory proteins within the serum, and decreased levels of the bacterial endotoxin protein in the asthmatic state. Comparison of blood microbiome composition revealed a significant increase in the Firmicutes phylum with asthma that was associated with a concomitant reduction in the Proteobacteria phylum. This study provides a valuable insight into the systemic changes evident in the HDM-associated asthma, identifies a range of molecules that are present in the circulation in a condition-specific manner (with clear biomarker potential), and highlights a range of hypotheses for further study.

Understanding the importance of key risk factors in predicting chronic bronchitic symptoms using a machine learning approach

BACKGROUND

Chronic respiratory symptoms involving bronchitis, cough and phlegm in children are underappreciated but pose a significant public health burden. Efforts for prevention and management could be supported by an understanding of the relative importance of determinants, including environmental exposures. Thus, we aim to develop a prediction model for bronchitic symptoms.

METHODS

Schoolchildren from the population-based southern California Children's Health Study were visited annually from 2003 to 2012. Bronchitic symptoms over the prior 12 months were assessed by questionnaire. A gradient boosting model was fit using groups of risk factors (including traffic/air pollution exposures) for all children and by asthma status. Training data consisted of one observation per participant in a random study year (for 50% of participants). Validation data consisted of: (1) a random (later) year in the same participants (within-participant); (2) a random year in participants excluded from the training data (across-participant).

RESULTS

At baseline, 13.2% of children had asthma and 18.1% reported bronchitic symptoms. Models performed similarly within- and across-participant. Previous year symptoms/medication use provided much of the predictive ability (across-participant area under the receiver operating characteristic curve (AUC): 0.76 vs 0.78 for all risk factors, in all participants). Traffic/air pollution exposures added modestly to prediction as did body mass index percentile, age and parent stress.

CONCLUSIONS

Regardless of asthma status, previous symptoms were the most important predictors of current symptoms. Traffic/air pollution variables contribute modest predictive information, but impact large populations. Methods proposed here could be generalized to personalized exacerbation predictions in future longitudinal studies to support targeted prevention efforts.

Predicting future risk of exacerbations in Japanese patients with adult asthma: A prospective 1-year follow up study

BACKGROUND

To avoid future risk is a definitive goal of long-term asthma management. Exacerbations are considered to be the most relevant future risk in real life asthma management. Few comparative studies have evaluated the risk factors associated with exacerbations in Japanese patients with asthma.

METHODS

We performed the prospective 1-year follow up study in Japanese patients with adult asthma. A total of 189 patients with asthma were enrolled and followed up for 1 year. Finally, 181 patients completed the study protocol.

RESULTS

Of 181 patients, 43 patients (23.8%) had exacerbations during the follow-up period. Among the 45 patients who had exacerbations during the preceding year, 32 patients (71.1%) had exacerbations. Prevalence of patients with previous exacerbations and those with previous admissions were significantly higher in patients with exacerbations than those with no exacerbation. Logistic regression analysis also identified a significant association between exacerbations during the follow-up period and exacerbations during the preceding year, admissions during the preceding 3 years, ACT score below 20, low %FVC (<80%), or low FEV₁ (<70%), respectively. Of the 55 patients with severe asthma, 29 patients (52.7%) had exacerbations. Among the 36 patients with severe asthma with previous exacerbations, 26 patients (72.2%) had exacerbations. The history of exacerbations during the preceding year was associated with a significantly increased risk of exacerbations both among the patients with severe asthma and those with non-severe asthma.

CONCLUSIONS

This study implicated that exacerbations during the preceding year reliably predict future risk of exacerbations in Japanese patients with asthma.

A Retrospective Study of the Effectiveness of the AeroChamber Plus® Flow-Vu® Antistatic Valved Holding Chamber for Asthma Control

Introduction

Electrostatic charge in valved holding chambers (VHCs) may lead to inconsistent metered-dose inhaler (MDI) asthma drug delivery. We compared the AeroChamber Plus^® Flow Vu^® Antistatic Valved Holding Chamber (AC⁺FV AVHC) with non-antistatic control VHCs in terms of asthma exacerbations, resource use, and cost in an asthma population.

Methods

Patients included in an adjudicated claims database with AC⁺FV AVHC or non-antistatic VHC (control VHC) use between 1/2010 and 8/2015 (index) who were treated with an inhaled corticosteroid (ICS) or a combination of an ICS and a long-acting β2 agonist MDI within 60 days before or after the index date, were diagnosed with asthma, and had ≥12 months of pre- and ≥30 days of post-index health plan enrollment were included. Cohorts were matched 1:1 using propensity scores. We compared incidence rates (IR) of exacerbation, time to first exacerbation using Kaplan–Meier survival analysis, occurrence of exacerbations, and healthcare resource use and costs using generalized linear models.

Results

9325 patients in each cohort were identified. The IR of exacerbations per 100 person-days (95% CI) was significantly higher in the control VHC cohort than the AC⁺FV AVHC cohort [0.161 (0.150–0.172) vs. 0.137 (0.128–0.147)]. A higher proportion of exacerbation-free patients was observed in the AC⁺FV AVHC cohort. Among the 4293 patients in each cohort with ≥12 months of follow-up, AC⁺FV AVHC patients were found to be 10–12% less likely than control VHC patients to experience an exacerbation throughout the study period. A lower proportion of the AC⁺FV AVHC patients had an ED visit compared to the control VHC patients (10.8% vs. 12.4%). Exacerbation-related costs for the AC⁺FV AVHC cohort were 23%, 25%, 20%, and 12% lower than those for the control VHC cohort at 1, 6, 9, and 12 months, respectively.

Conclusions

The AC⁺FV AVHC was associated with lower exacerbation rates, delayed time to first exacerbation, and lower exacerbation-related costs when compared to control non-antistatic VHCs.

Adding Social Determinant Data Changes Children's Hospitals' Readmissions Performance

OBJECTIVES

To determine whether social determinants of health (SDH) risk adjustment changes hospital-level performance on the 30-day Pediatric All-Condition Readmission (PACR) measure and improves fit and accuracy of discharge-level models.

STUDY DESIGN

We performed a retrospective cohort study of all hospital discharges meeting criteria for the PACR from 47 hospitals in the Pediatric Health Information database from January to December 2014. We built four nested regression models by sequentially adding risk adjustment factors as follows: chronic condition indicators (CCIs); PACR patient factors (age and sex); electronic health record-derived SDH (race, ethnicity, payer), and zip code-linked SDH (families below poverty level, vacant housing units, adults without a high school diploma, single-parent households, median household income, unemployment rate). For each model, we measured the change in hospitals' readmission decile-rank and assessed model fit and accuracy.

RESULTS

For the 458 686 discharges meeting PACR inclusion criteria, in multivariable models, factors associated with higher discharge-level PACR measure included age <1 year, female sex, 1 of 17 CCIs, higher CCI count, Medicaid insurance, higher median household income, and higher percentage of single-parent households. Adjustment for SDH made small but significant improvements in fit and accuracy of discharge-level PACR models, with larger effect at the hospital level, changing decile-rank for 17 of 47 hospitals.

CONCLUSIONS

We found that risk adjustment for SDH changed hospitals' readmissions rate rank order. Hospital-level changes in relative readmissions performance can have considerable financial implications; thus, for pay for performance measures calculated at the hospital level, and for research associated therewith, our findings support the inclusion of SDH variables in risk adjustment.

Predictive factors for moderate or severe exacerbations in asthma patients receiving outpatient care

BACKGROUND

Asthma exacerbations are important events that affect disease control, but predictive factors for severe or moderate exacerbations are not known. The objective was to study the predictive factors for moderate (ME) and severe (SE) exacerbations in asthma patients receiving outpatient care.

METHODS

Patients aged > 12 years with asthma were included in the study and followed-up at 4-monthly intervals over a 12-month period. Clinical (severity, level of control, asthma control test [ACT]), atopic, functional, inflammatory, SE and ME parameters were recorded. Univariate analysis was used to compare data from patients presenting at least 1 SE or ME during the follow-up period vs no exacerbations. Statistically significant (p <0.1) factors were then subjected to multiple analysis by binary logistic regression.

RESULTS

A total of 330 patients completed the study, most of whom were atopic (76%), women (nearly 70%), with moderate and mild persistent asthma (>80%). Twenty-seven patients (8%) had a SE and 183 had a ME (58.5%) during follow-up. In the case of SEs, the only predictive factor identified in the multiple analysis was previous SE (baseline visit OR 4.218 95% CI 1.53-11.58, 4-month follow-up OR 6.88 95% CI 2.018-23.51) and inhalation technique (OR 3.572 95% CI 1.324-9.638). In the case of MEs, the only predictive factor found in the multiple analysis were previous ME (baseline visit OR 2.90 95% CI 1.54-5.48, 4-month follow- up OR 1.702 95% CI 1.146-2.529).

CONCLUSIONS

The primary predictive factor for SE or ME is prior SE or ME, respectively. SEs seem to constitute a specific patient "phenotype", in which the sole predictive factor is prior SEs.

Identifying Risk of Future Asthma Attacks Using UK Medical Record Data: A Respiratory Effectiveness Group Initiative

BACKGROUND

Asthma attacks are common, serious, and costly. Individual factors associated with attacks, such as poor symptom control, are not robust predictors.

OBJECTIVE

We investigated whether the rich data available in UK electronic medical records could identify patients at risk of recurrent attacks.

METHODS

We analyzed anonymized, longitudinal medical records of 118,981 patients with actively treated asthma (ages 12-80 years) and 3 or more years of data. Potential risk factors during 1 baseline year were evaluated using univariable (simple) logistic regression for outcomes of 2 or more and 4 or more attacks during the following 2-year period. Predictors with significant univariable association (P < .05) were entered into multiple logistic regression analysis with backward stepwise selection of the model including all significant independent predictors. The predictive accuracy of the multivariable models was assessed.

RESULTS

Independent predictors associated with future attacks included baseline-year markers of attacks (acute oral corticosteroid courses, emergency visits), more frequent reliever use and health care utilization, worse lung function, current smoking, blood eosinophilia, rhinitis, nasal polyps, eczema, gastroesophageal reflux disease, obesity, older age, and being female. The number of oral corticosteroid courses had the strongest association. The final cross-validated models incorporated 19 and 16 risk factors for 2 or more and 4 or more attacks over 2 years, respectively, with areas under the curve of 0.785 (95% CI, 0.780-0.789) and 0.867 (95% CI, 0.860-0.873), respectively.

CONCLUSIONS

Routinely collected data could be used proactively via automated searches to identify individuals at risk of recurrent asthma attacks. Further research is needed to assess the impact of such knowledge on clinical prognosis.

Retrospective cohort analysis of healthcare claims in the United States characterising asthma exacerbations in paediatric patients

Background

Asthma is the most common chronic disease in childhood and places a significant burden on public and private health systems. This retrospective cohort analysis utilised administrative healthcare claims data (US Clinformatics™ Multiplan database; compliant with the US Department of Health & Human Services Health Insurance Portability and Accountability Act) to characterise asthma exacerbations requiring intervention in a US paediatric patient population.

Methods

Patients aged > 1–17 years with a recorded asthma diagnosis and receiving treatment were identified in the US Clinformatics™ Multiplan database over a 9-year period (2004–2012). Both incident and prevalent cases of asthma were included, with the most recently recorded asthma diagnosis designated as the index date. The 12-month period following the index date was analysed for asthma exacerbations, defined as an event requiring treatment with systemic corticosteroid or resulting in an asthma-related hospitalisation or emergency department visit.

Results

Data from 734,114 children with asthma (41.5 % females, 58.5 % males) were analysed, of this cohort 34.4 % experienced ≥ 1 exacerbation during the follow-up period. The proportion who experienced ≥ 1 exacerbation increased from 28.9 % in 2004 to 36.3 % in 2012, based on the reported index date. Their mean annual exacerbation frequency was 1.4; 85.8 % of exacerbations were defined by systemic corticosteroids use. A consistent trend of increased exacerbation incidence in the fall and early winter was observed, in particular exacerbations defined by systemic corticosteroid use. A greater proportion of asthma-related hospitalisations were associated with younger age.

Conclusions

Approximately one-third of children experienced ≥ 1 exacerbation in real-world clinical practice. A targeted treatment approach with a focus on those with a history of recurrent exacerbations is recommended to improve asthma control. This targeted approach could also minimise the frequent systemic corticosteroid exposure particularly at an early age when side effects of systemic corticosteroids are more pronounced.

Predictors of severe exacerbations, poor asthma control, and β-agonist overuse for patients with asthma

BACKGROUND

Predictors of asthma exacerbations, poor asthma control, or extreme β-agonist overuse may be of clinical utility in the management of asthma.

OBJECTIVE

To investigate characteristics that predict subsequent adverse outcomes in asthma.

METHODS

An independent 24-week, randomized controlled trial of 303 adult patients with asthma who are at risk, which compared the efficacy of SMART (single budesonide-formoterol inhaler as maintenance and reliever therapy) with a fixed-dose regimen with salbutamol as reliever ("Standard"). Inhaled medication use was measured by electronic monitoring. Baseline characteristics that were predictors of subsequent severe asthma exacerbations, poor asthma control (Asthma Control Questionnaire -5 score ≥1.5), and "extreme" β-agonist overuse (>16 budesonide-formoterol actuations/d in SMART and >32 salbutamol actuations/d in Standard) were assessed by multivariate analyses.

RESULTS

FEV₁ % predicted (rate ratio [RR] 1.14 [95% CI, 1.03-1.27] per 10% lower), more previous exacerbations (RR 1.15 [95% CI, 1.01-1.31]), Standard therapy (RR 1.62 [95% CI, 1.07-2.47]), and female sex (RR 2.18 [95% CI, 1.29-3.67]) were associated with future severe exacerbations. Asthma Control Questionnaire--5 (regression coefficient 0.20 [95% CI, 0.13-0.27] per 0.5 points higher) and age (regression coefficient 0.09 [95% CI, 0.01-0.17] per decade older) were associated with future poorly controlled asthma. Higher reliever use (RR 1.63 [95% CI, 1.36-1.95] per categorical score in Asthma Control Questionnaire question no. 6), Māori ethnicity (RR 2.20 [95% CI, 1.43-3.38]) and FEV₁ % predicted (RR 1.16 [95% CI, 1.03-1.31] per 10% lower) were associated with future extreme β-agonist overuse.

CONCLUSION

Future severe asthma exacerbations, poor asthma control, and extreme β-agonist overuse are predicted by different baseline clinical and demographic characteristics and management approaches in at-risk asthma.

BuShenYiQi Formula strengthens Th1 response and suppresses Th2-Th17 responses in RSV-induced asthma exacerbated mice

ETHNOPHARMACOLOGICAL RELEVANCE

The prevalence of allergic asthma has been increased rapidly in recent years. About 20% of all these sufferers have experienced asthma exacerbation. Although corticosteroids and β-agonists therapy improves serious asthma symptoms, they can׳t completely cure these allergic diseases. BuShenYiQi Formula (BSYQF) has been widely used to treat bronchial asthma and its exacerbation for decades in Huashan Hospital of Fudan University, China. Nevertheless, the mechanisms of BSYQF' anti-asthmatic effects haven׳t been fully elucidated. In this study, we evaluated the involvement of Th1, Th2 and Th17 cells in the anti-asthmatic effects of BSYQF in Respiratory Syncytial Virus (RSV)-induced asthma exacerbated mice.

MATERIALS AND METHODS

BALB/c mice were challenged with ovalbumin (OVA), followed by RSV infections for establishment of asthma exacerbated model. Airway hyperresponsiveness (AHR) was examined by direct airway resistance analysis. Bronchoalveolar lavage fluid (BALF) was assessed for inflammatory cell counts and secreted levels of cytokines. Lung tissues were detected for inflammatory cell infiltration and mucus hypersecretion. Subsequently, CD4(+)T cells and alveolar macrophages were sorted and purified from mice lungs in different groups. CD4(+)T cell subpopulations including the expression levels of important transcription factors in T lymphocyte polarization were examined. In asthma exacerbation group, the purified CD4(+)T cells and macrophages were co-cultured, and the changes of co-cultured cells with BSYQF treatment were further analyzed in vitro.

RESULTS

BSYQF significantly attenuated airway hyperresponsiveness and inhibited inflammatory cell infiltration, especially for excessive infiltration of eosinophils and neutrophils. Histopathological analysis showed that BSYQF could suppress airway inflammation and RSV replication. The decreases of antigen-specific IgE, IL-4, IL-5, IL-6, IL-17a and increases of IFN-γ, IL-12 were observed in BALF, lung homogenate or serum after BSYQF treatment. We further confirmed that BSYQF could down-regulate Th2-Th17 cell proportions with lower expressions of GATA3, STAT6 and RORγT, and up-regulate Th1 cell proportion with higher expression of T-bet. And as a result of strengthened Th1-response, activated macrophages were also observed by remarkable enhancement of signature gene expressions and phagocytosis.

CONCLUSIONS

BSYQF can significantly attenuate RSV-induced asthma exacerbation. These effects may be mediated at least partially by regulating the balance between Th1 and Th2-Th17 responses.

Asthma exacerbations: predisposing factors and prediction rules

PURPOSE OF REVIEW

Asthma is a multifaceted disease that is associated with decreased lung function, multiple symptoms, varying levels of asthma control, and risk of acute exacerbations. The ability to predict the risk of developing acute exacerbations may improve the management of asthmatics and facilitate identification of these patients for interventional studies.

RECENT FINDINGS

Factors that are associated with different manifestations of asthma differ. Biomarkers that are correlated with airways hyper-responsiveness do not necessarily correlate with risk of future exacerbations. Genetic factors that segregate with exacerbation risk are beginning to emerge. Outcome measures that demonstrate predictive validity have been developed and may facilitate patient management and provide novel clinically meaningful endpoints in clinical trials.

SUMMARY

This review will emphasize underlying factors associated with asthma exacerbations and clinical prediction rules that correlate with the risk of developing severe exacerbations of asthma.

Electronic health record-based assessment of oral corticosteroid use in a population of primary care patients with asthma: an observational study

Background

Oral corticosteroid prescriptions are often used in clinical studies as an indicator of asthma exacerbations. However, there is rarely the ability to link a prescription to its associated diagnosis. The objective of this study was to characterize patterns of oral corticosteroid prescription orders for asthma patients using an electronic health record database, which links each prescription order to the diagnosis assigned at the time the order was placed.

Methods

This was a retrospective cohort study of the electronic health records of asthma patients enrolled in the Geisinger Health System from January 1, 2001 to August 23, 2010. Eligible patients were 12–85 years old, had a primary care physician in the Geisinger Health System, and had asthma. Each oral corticosteroid order was classified as being prescribed for an asthma-related or non-asthma-related condition based on the associated diagnosis. Asthma-related oral corticosteroid use was classified as either chronic or acute. In patient-level analyses, we determined the number of asthma patients with asthma-related and non-asthma-related prescription orders and the number of patients with acute versus chronic use. Prescription-level analyses ascertained the percentages of oral corticosteroid prescription orders that were for asthma-related and non-asthma-related conditions.

Results

Among the 21,199 asthma patients identified in the electronic health record database, 15,017 (70.8%) had an oral corticosteroid prescription order. Many patients (N = 6,827; 45.5%) had prescription orders for both asthma-related and non-asthma-related conditions, but some had prescription orders exclusively for asthma-related (N = 3,450; 23.0%) or non-asthma-related conditions (N = 4,740; 31.6%). Among the patients receiving a prescription order, most (87.5%) could be classified as acute users. A total of 60,355 oral corticosteroid prescription orders were placed for the asthma patients in this study—31,397 (52.0%) for non-asthma-related conditions, 24,487 (40.6%) for asthma-related conditions, and 4,471 (7.4%) for both asthma-related and non-asthma-related conditions.

Conclusions

Oral corticosteroid prescriptions for asthma patients are frequently ordered for conditions unrelated to asthma. A prescription for oral corticosteroids may be an unreliable marker of asthma exacerbations in retrospective studies utilizing administrative claims data. Investigators should consider co-morbid conditions for which oral corticosteroid use may also be indicated and/or different criteria for assessing oral corticosteroid use for asthma.

Efficacy and safety of maintenance and reliever combination budesonide-formoterol inhaler in patients with asthma at risk of severe exacerbations: a randomised controlled trial

BACKGROUND

The Single combination budesonide-formoterol inhaler Maintenance And Reliever Therapy (SMART) regimen reduces severe asthma exacerbations in patients, but whether the high doses of corticosteroid and β agonist increase the risk of adverse effects with both short-term and cumulative exposure is not certain. Our aim was to investigate whether the SMART regimen would reduce the risk of overuse of β agonist, reduce the likelihood of patients to seek medical review when such episodes occurred, and if any reduction in severe asthma exacerbations would be at the cost of a higher burden of systemic corticosteroid.

METHODS

In this 24-week trial undertaken at four primary health-care practices and one hospital in New Zealand, patients (aged 16-65 years) with a recent asthma exacerbation were randomly assigned in a 1:1 ratio to the SMART or standard fixed-dose regimen. Treatment in the SMART group consisted of two actuations of budesonide-formoterol (200 μg and 6 μg, respectively, per actuation) twice daily, delivered through a combination metered dose inhaler (MDI), with one extra actuation as needed for relief of symptoms; treatment in the standard group consisted of two actuations of budesonide-formoterol (200 μg and 6 μg, respectively, per actuation) twice daily through a combination MDI with one to two actuations of salbutamol (100 μg per actuation) by MDI as needed for relief of symptoms. MDIs were monitored electronically to measure actual use of medication. The allocation sequence for randomisation was computer generated, with a block size of eight per site. Participants, investigators, and the statistician were not masked to group assignment. The primary outcome was the proportion of participants with at least one high-use episode of β agonist (more than eight actuations per day of budesonide-formoterol in addition to the four maintenance doses in the SMART group or more than 16 actuations per day of salbutamol in the standard group). Analysis was by intention to treat. This trial is registered with the Australian New Zealand Clinical Trials Registry, number ACTRN12610000515099.

FINDINGS

303 patients were randomly assigned to the SMART (n=151) or standard group (n=152). No significant difference was noted between the SMART and standard groups in the proportion of participants with at least one high-use episode of β agonist (84 [56%] vs 68 [45%], respectively, relative risk 1·24 [95% CI 0·99-1·56]; p=0·058). There were fewer days of high use in the SMART group (mean 5·1 days [SD 14·3] vs 8·9 days [20·9], relative rate 0·58 [0·39-0·88]; p=0·01). Of the patients who had at least one high-use episode, those in the SMART group had fewer days of high use without medical review (8·5 days [17·8] vs 18·3 days [24·8], 0·49 [0·31-0·75]; p=0·001). The SMART regimen resulted in higher inhaled corticosteroid exposure (943·5 μg budesonide per day [1502·5] vs 684·3 μg budesonide per day [390·5], respectively; ratio of means 1·22 [1·06-1·41]; p=0·006), but reduced oral corticosteroid exposure (77·5 mg prednisone [240·5] vs 126·6 mg prednisone [382·1], respectively; p=0·011), with no significant difference in composite systemic corticosteroid exposure (793·7 mg prednisone equivalent per year [893·1] vs 772·1 mg prednisone equivalent per year [1062·7], respectively; 1·03 [0·86-1·22]; p=0·76). Participants in the SMART group had fewer severe asthma exacerbations (35 [weighted mean rate per year 0·53] vs 66 [0·97]; relative rate 0·54 [0·36-0·82]; p=0·004).

INTERPRETATION

The SMART regimen has a favourable risk-to-benefit profile and can be recommended for use in adults at risk of severe asthma exacerbations.

FUNDING

Health Research Council of New Zealand.

Prescription-acquired acetaminophen use and the risk of asthma in adults: a case-control study

BACKGROUND

Studies have examined the association between acetaminophen use and asthma; however, their interpretation is limited by several methodologic issues.

OBJECTIVE

To investigate the association between recent and chronic prescription-acquired acetaminophen use and asthma.

METHODS

This retrospective case-control study used a 10% random sample of the IMS LifeLink commercial claims data from 1997 to 2009. Cases had to have at least 1 incident claim of asthma; 3:1 controls matched on age, sex, and region were randomly chosen. Acetaminophen exposure, dose, and duration were measured in the 7- and 30-day (recent) and the 1-year (chronic) look-back periods. Multivariable conditional logistic regression was used to estimate the risk of asthma associated with acetaminophen use adjusted for comorbidities, other drugs increasing asthma risk, and health system factors.

RESULTS

There were 28,892 cases and 86,676 controls, with mean age of 42.8 years; 37.7% were males, and 22.6% of cases and 18.2% of controls had acetaminophen exposure in the pre-index year, with mean cumulative doses of 78.7 g and 59.8 g, respectively. There was no significant association between recent prescription acetaminophen exposure and asthma (7 days: OR 1.02, p = 0.74; 30 days: OR 0.97, p = 0.38). Cumulative prescription acetaminophen dose in the year prior increased asthma risk compared to acetaminophen nonusers (≤1 kg: OR 1.09, p < 0.001 and >1 kg: OR = 1.60, p = 0.02). Duration of prescription acetaminophen use greater than 30 days was associated with elevated asthma risk (OR 1.39, p < 0.001).

CONCLUSIONS

Chronic prescription-acquired acetaminophen use was associated with an increased risk of asthma, while recent use was not. However, over-the-counter acetaminophen use was not captured in this study and further epidemiologic research with complete acetaminophen exposure ascertainment and research on pathophysiologic mechanisms is needed to confirm these relationships.

Respiratory syncytial virus reverses airway hyperresponsiveness to methacholine in ovalbumin-sensitized mice

Each year, approximately 20% of asthmatics in the United States experience acute symptom exacerbations, which commonly result from pulmonary viral infections. The majority of asthma exacerbations in very young children follow infection with respiratory syncytial virus (RSV). However, pathogenic mechanisms underlying induction of asthma exacerbations by RSV are not well understood. We therefore investigated the effect of post-sensitization RSV infection on lung function in ovalbumin (OVA)-sensitized BALB/c mice as a model of RSV asthma exacerbations. OVA sensitization of uninfected female BALB/c mice increased bronchoalveolar lavage fluid (BALF) eosinophil levels and induced airway hyperresponsiveness to the muscarinic agonist methacholine, as measured by the forced-oscillation technique. In contrast, intranasal infection with replication-competent RSV strain A2 for 2–8 days reduced BALF eosinophil counts and reversed airway hyperresponsiveness in a pertussis toxin-sensitive manner. BALF levels of the chemokine keratinocyte cytokine (KC; a murine homolog of interleukin-8) were elevated in OVA-sensitized, RSV-infected mice and reversal of methacholine hyperresponsiveness in these animals was rapidly inhibited by KC neutralization. Hyporesponsiveness could be induced in OVA-sensitized, uninfected mice by recombinant KC or the Gαi agonist melittin. These data suggest that respiratory syncytial virus induces KC-mediated activation of Gαi, resulting in cross-inhibition of Gαq-mediated M₃-muscarinic receptor signaling and reversal of airway hyperresponsiveness. As in unsensitized mice, KC therefore appears to play a significant role in induction of airway dysfunction by respiratory syncytial virus. Hence, interleukin-8 may be a promising therapeutic target to normalize lung function in both asthmatics and non-asthmatics with bronchiolitis. However, the OVA-sensitized, RSV-infected mouse may not be an appropriate model for investigating the pathogenesis of viral asthma exacerbations.

Predicting asthma exacerbations in children

PURPOSE OF REVIEW

This review critically assesses recently published literature on predicting asthma exacerbations in children, while also providing general recommendations for future research in this field.

RECENT FINDINGS

Current evidence suggests that every effort should be made to provide optimal treatment to achieve adequate asthma control, as this will significantly reduce the risk of severe disease exacerbations. Children who have had at least one asthma exacerbation in the previous year are at highest risk for subsequent exacerbations, regardless of disease severity and/or control. Although several tools and biomarkers to predict asthma exacerbations have been recently developed, these approaches need further validation and/or have only had partial success in identifying children at risk.

SUMMARY

Although considerable progress has been made, much remains to be done. Future studies should clearly differentiate severe asthma exacerbations due to inadequate asthma control from those occurring in children whose asthma is well controlled, utilize standardized definitions of asthma exacerbations, and use a systematic approach to identify the best predictors after accounting for the multiple dimensions of the problem. Our ability to correctly predict the development of severe asthma exacerbations in an individual child should improve in parallel with increased knowledge and/or understanding of the complex interactions among genetic, environmental (e.g. viral infections) and lifestyle (e.g. adherence to treatment) factors underlying these events.

Current control and future risk in asthma management

Despite international and national guidelines, poor asthma control remains an issue. Asthma exacerbations are costly to both the individual, and the healthcare provider. Improvements in our understanding of the therapeutic benefit of asthma therapies suggest that, in general, while long-acting bronchodilator therapy improves asthma symptoms, the anti-inflammatory activity of inhaled corticosteroids reduces acute asthma exacerbations. Studies have explored factors which could be predictive of exacerbations. A history of previous exacerbations, poor asthma control, poor inhaler technique, a history of lower respiratory tract infections, poor adherence to medication, the presence of allergic rhinitis, gastro-oesophageal reflux disease, psychological dysfunction, smoking and obesity have all been implicated as having a predictive role in the future risk of asthma exacerbation. Here we review the current literature and discuss this in the context of primary care management of asthma.

Monitoring asthma status

PURPOSE

Asthma is a chronic disorder of the airways involving inflammation and airway hyper-reactivity. Clinical diagnosis and monitoring of asthma must incorporate the immunological, biochemical, and histological changes of a chronic disorder, while recognizing acute phenotypic changes in order to optimally tailor therapeutics to each individual.

RECENT FINDINGS

Articles published within the previous 18 months are summarized in this article in order to present an up to date review of the latest findings regarding the monitoring of asthma. The articles encompass a wide array of specialties from basic research and histology to clinical medicine as well as community medicine and nursing.

SUMMARY

Exciting new advancements in the monitoring of asthma continue to unfold. Potentially new diagnostic and monitoring tools are highlighted in this study. Continued investigations may enable a select few methodologies to reach clinical utility in the ongoing monitoring and treatment of patients with asthma.

Hospitalizations for asthma in children are linked to undertreatment and insufficient asthma education

BACKGROUND

Most hospital admissions for asthma exacerbation are avoidable with adequate disease management.

OBJECTIVES

The objective of this study was to describe the characteristics of children hospitalized with an asthma exacerbation to identify modifiable factors leading to hospitalization.

METHODS

The study was conducted in 14 pediatric units and included children 3-17 years of age who were hospitalized for an asthma exacerbation. The present analysis covers 498 children with known asthma. Staff physicians used a standardized questionnaire to collect data. Asthma history came from a parental interview and included usual asthma care, frequency of symptoms and quick-relief medication use in the previous month, frequency of exacerbations and number of unscheduled healthcare visits during the past year, and prior asthma-related hospitalizations.

RESULTS

More than half the children had previously been hospitalized for an exacerbation, 42% used continuous inhaled corticosteroids, and 57% had a regular follow-up for asthma. Asthma had been well controlled over the past year for 11%, 12% had experienced exacerbations during the past year but that had been optimally controlled during the previous month, and 11% had recently become poorly controlled (infrequent exacerbations in the previous year and non-optimal control in the previous month). The remaining 327 children (66%) were consistently poorly controlled (non-optimal asthma control in the previous month and frequent exacerbations over the previous year). Among this group, 69% had at least one of the following preventable risk factors for hospitalization: no regular controller therapy (49%), no asthma action plan (40%), or no follow-up for asthma (35%).

CONCLUSIONS

Two-thirds of the children with asthma hospitalized for an exacerbation had been consistently poorly controlled during the previous year. They were frequently undertreated and insufficiently educated about asthma. Further efforts are needed to improve asthma treatment and education in France.