(Correcting) misdiagnoses of asthma: a cost effectiveness analysis

Anticipating undiagnosed asthma in symptomatic adults with normal pre- and post-bronchodilator spirometry: a decision tool for bronchial challenge testing

BACKGROUND

Some patients with asthma demonstrate normal spirometry and remain undiagnosed without further testing.

OBJECTIVE

To determine clinical predictors of asthma in symptomatic adults with normal spirometry, and to generate a tool to help clinicians decide who should undergo bronchial challenge testing (BCT).

METHODS

Using random-digit dialling and population-based case-finding, we recruited adults from the community with respiratory symptoms and no previous history of diagnosed lung disease. Participants with normal pre- and post-bronchodilator spirometry subsequently underwent BCT. Asthma was diagnosed in those with symptoms and a methacholine provocative concentration (PC20) of < 8 mg/ml. Sputum and blood eosinophils, and exhaled nitric oxide were measured. Univariate analyses identified potentially predictive variables, which were then used to construct a multivariable logistic regression model to predict asthma. Model sensitivity, specificity, and area under the receiver operating curve (AUC) were calculated.

RESULTS

Of 132 symptomatic individuals with normal spirometry, 34 (26%) had asthma. Of those ultimately diagnosed with asthma, 33 (97%) answered 'yes' to a question asking whether they experienced cough, chest tightness or wheezing provoked by exercise or cold air. Other univariate predictors of asthma included female sex, pre-bronchodilator FEV1 percentage predicted, and percent positive change in FEV1 post bronchodilator. A multivariable model containing these predictive variables yielded an AUC of 0.82 (95% CI: 0.72-0.91), a sensitivity of 82%, and a specificity of 66%. The model was used to construct a nomogram to advise clinicians which patients should be prioritized for BCT.

CONCLUSIONS

Four readily available patient characteristics demonstrated a high sensitivity and AUC for predicting undiagnosed asthma in symptomatic adults with normal pre- and post-bronchodilator spirometry. These characteristics can potentially help clinicians to decide which individuals with normal spirometry should be investigated with bronchial challenge testing. However, further prospective validation of our decision tool is required.

An update on asthma diagnosis

OBJECTIVE

Asthma imposes a significant health and socioeconomic burden with an average prevalence impacting 5-10% of the global population. The aim of this narrative review is to update the current literature on topics related to asthma diagnosis.

DATA SOURCES

Original research articles were identified from PubMed using the search terms "asthma diagnosis" and "asthma misdiagnosis".

STUDY SELECTIONS

Recently published articles (n = 51) detailing the diagnosis, misdiagnosis of asthma, and the updated recommendations of the European and international asthma guidelines.

RESULTS

Emerging evidence revealed that asthma might represent a rather heterogenous clinical entity with varying underlying molecular mechanisms. Attempts have been made to unravel these traits to better provide accurate diagnosis and a more efficient patient-based management approach. The lack of a gold standard test for asthma diagnosis has contributed to its over- and underdiagnosis. This is problematic, given that overdiagnosis might lead to delay of both diagnosis and prompt treatment of other diseases, while underdiagnosis might substantially impact quality of life due to progression of asthma by increased rate of exacerbations and airway remodeling. In addition to poor asthma control and potential patient harm, asthma misdiagnosis is also associated with excessive costs. As a result, current international guidelines emphasize the need for a standardized approach to diagnosis, including objective measurements prior to treatment.

CONCLUSION

Future research is warranted to define the optimal diagnostic and treatable traits approach especially for patients with severe asthma, as they may benefit from the advent of newly targeted asthma management.

Misdiagnosis asthma in adult, three rare causes

INTRODUCTION

All that wheezes is not asthma. Although, asthma is the most common cause of wheeze and cough in children and adults, it is often attributed inappropriately to these symptoms from other causes.

AIM

We illustrate through this manuscript three rare causes of wheeze in adults, misdiagnosis as asthma.

OBSERVATIONS

The three reported cases were misdiagnosed as difficult-to-treat asthma. They were found as mimicking asthma. Final diagnoses were localized tracheobronchial amyloidosis, aortic arch anomalies, and idiopathic chronic eosinophilic pneumonia.

CONCLUSION

Although asthma is a common cause of various respiratory symptoms, all that coughs and wheezes is not asthma. So before retaining the severe asthma diagnosis, we have to exclude various differential diagnoses, even the rarest ones. Several diagnostic tests have to be done to have the appropriate diagnosis.

Potential limitations of diagnostic standard codes to distinguish polycythemia vera and secondary erythrocytosis

Red cell overproduction is seen in polycythemia vera (PV), a bone marrow myeloproliferative neoplasm characterized by trilinear cell proliferation (WBC, platelets), as well as in secondary erythrocytosis (SE), a group of heterogeneous disorders characterized by elevated EPO gene transcription. We aimed to verify the concordance of the International Classification of Diseases (ICD) code-based diagnosis of “polycythemia” or “erythrocytosis” with the true clinical diagnosis of these conditions. We retrospectively reviewed the electronic medical records (January 1, 2005, to December 31, 2016) of adult patients with ICD codes of polycythemia and/or erythrocytosis who had testing done for the presence of the JAK2V617F mutation. We verified the accuracy of the ICD code-based diagnoses by meticulous chart review and established whether these patients fulfilled the criteria by the evaluating physician for PV or SE and according to the World Health Organization 2016 diagnostic guidelines. The reliability of ICD coding was calculated using Cohen's kappa. We identified and chart reviewed a total of 578 patient records. Remarkably, 11% of the patients had concurrent diagnosis codes for PV and SE and were unable to be classified appropriately without individual chart review. The ICD code-based diagnostic system led to misidentification in an important fraction of cases. This represents a problem for the detection of PV or SE cases by ICD-based registries and their derived studies. Research based exclusively on ICD codes could have a potential impact on patient care and public health, and limitations must be weighed when research findings are conveyed.

FeNO in Asthma

Asthma is a common disease affecting 350 million people worldwide, which is characterized by airways inflammation and hyperreactivity. Historically diagnosis and treatment have been mainly based on symptoms, which have the potential to result in misdiagnosis and inappropriate treatment. Nitric oxide (NO) is exhaled in human breath and is a marker of airways inflammation. Levels of NO are increased in the exhaled breath of patients with type 2 asthma and fractional exhaled nitric oxide (FeNO) provides an objective biomarker of airway inflammation. FeNO testing is an accessible, noninvasive, and easy-to-use test. Cut-off values have been established by the American Thoracic Society (ATS), the Global Initiative for Asthma (GINA), and the National Institute for Health and Care Excellence (NICE) but vary between guidance. FeNO levels have been shown to be predictive of blood and sputum eosinophil levels but should not be used in isolation and current guidance emphasizes the importance of incorporating clinical symptoms and testing when utilizing FeNO results. The inclusion of FeNO testing can increase diagnostic accuracy of asthma, while high levels in asthmatic patients can help predict response to inhaled corticosteroids (ICS) and suppression of levels with ICS to monitor adherence. FeNO levels are also a predictor of asthma risk with increased exacerbation rates and accelerated decline in lung function associated with high levels as well as having an emerging role in predicting response to some biologic therapies in severe asthma. FeNO testing is cost-effective and has been shown, when combined with clinical assessment, to improve asthma management.

Can oscillometry be a substitute to spirometry in the indigent?

The practical difficulties of using spirometry in a 3-year-old girl are highlighted, especially during the COVID-19 era. Oscillometry, a tidal breath-based technique, has shown promising future to reliably assess lung functions in the vulnerable cohort. A simple algorithmic approach has been provided till reference values can be established with multicenter studies.

The Impact of Quality Improvement Measures in the Management of Asthma Patients in Juvenile Detention Facilities

Asthma is a serious chronic lung disease with a significant economic burden. The population of the San Bernardino County Juvenile Detention and Assessment Centers have higher odds of asthma as compared to the general population. Research has shown that a significant number of patients with a prior history of asthma were misdiagnosed. A protocol using objective testing, along with the detailed patient's history, was successfully implemented to verify the diagnosis and guide more effective medical care. After the implementation of those steps, the prevalence of asthma was found to be lower with the new protocol, from 18.1% in the pre-protocol period to 11.2% in the post-protocol period. This decrease resulted in an associated reduction in both direct and indirect healthcare costs and more efficient medical care.

Assessment of airway reversibility in asthmatic children using forced oscillation technique - A single-center experience from North India

Background:

Lung function testing is recommended for the management of asthma. Due to certain limitations of conventional spirometry in vulnerable patients, forced oscillation technique (FOT) has been studied with promising results. As there is a paucity of data from developing world, we planned to conduct this study in children using FOT. To assess airway reversibility after inhaled salbutamol in asymptomatic children with suspected asthma.

Settings:

This study was conducted at pediatric asthma clinic of a tertiary care referral hospital in North India.

Design:

This was a prospective interventional study over 1-year period.

Subjects and Methods:

Asymptomatic children between 2 and 18 years of age, with history suggestive of asthma, were eligible for participation. Baseline and postbronchodilator pulmonary functions were assessed using FOT. Airway resistance and reactance were monitored at various frequencies. SPSS version 17 was used for statistical analysis.

Results:

Among the 345 enrolled children, baseline mean ± standard deviation total airway resistance (R₅), central airway resistance (R₁₉), peripheral airway resistance (R₅–R₁₉), reactance (X₅), and resonant frequency (Fres) were 6.85 ± 2.60, 5.23 ± 1.93, 1.6 ± 1.16, and − 2.54 ± 1.36 cmH₂O/L/s and 17.28 ± 3.06 Hz. The median (interquartile range) percentage change after inhaled salbutamol was 19.9 (11.40, 29.12), 22.86 (6.88, 38.76), 14.08 (3.40, 22.62), 39.20 (8.20, 62.39), and 15.79 (8.33, 27.27) in respective parameters. All changes were statistically significant. The studied respiratory variables were in maximum negative correlation with height, followed by body mass index.

Conclusions:

FOT is a simple technique for monitoring lung functions in children during asthma management.

Prevalence of modifiable factors limiting treatment efficacy of poorly controlled asthma patients: EFIMERA observational study

Several modifiable factors leading to poor asthma control have been described. We aimed to determine the proportion of patients with inadequate treatment, adherence to it, or critical mistakes with inhaler technique, and their impact on asthma control. We conducted a cross-sectional multicenter observational study including asthma patients referred from primary to specialist care for the first time. Data collected were adequate prescription according to guidelines, treatment adherence, and disease control. Of the 1682 patients (age 45 ± 17 years, 64.6% men), 35.9% showed inadequate prescription, 76.8% low adherence, and 17% critical mistakes with inhaler technique, with significantly less critical mistakes among Easyhaler users versus other dry powder inhaler users (10.3 versus 18.4%; p < 0.05). Factors related to bad asthma control were inadequate prescription (OR: 3.65), non-adherence to treatment (OR: 1.8), and inhaler misuse (OR: 3.03). A higher number of risk factors were associated with a higher probability of having badly controlled asthma.

Knowledge, practice pattern and attitude toward asthma management amongst physicians from Nepal, Malaysia, Lebanon, Myanmar and Morocco

OBJECTIVE

This survey aimed to understand the physicians' practice pattern and challenges faced while treating their patients with asthma in five countries-Malaysia, Nepal, Myanmar, Morocco and Lebanon.

METHODS

Questionnaire-based data was gathered from internal medicine doctors (209), general practitioners (206), chest physicians (152) and pediatricians (58) from 232 locations from across the five countries.

RESULTS

Of the 816 physicians, 374 physicians encountered at least 5 asthma patients daily. Approximately, 38% physicians always used spirometry for diagnosis and only 12% physicians always recommended Peak flow meter (PFM) for home-monitoring. Salmeterol/fluticasone (71%) followed by formoterol/budesonide (38%) were the most preferred ICS/long-acting beta₂-agonists (LABA); Salbutamol (78%) was the most preferred reliever medication. 60% physicians said >40% of their patients were apprehensive to use inhalers. 72% physicians preferred a pressurized metered-dose inhaler (pMDI) to a dry powder inhaler (DPI) with only a third of them using a spacer with the pMDI. 71% physicians believed that using similar device for controller and reliever can be beneficial to patients. Skipping medicines in absence of symptoms (64%), incorrect inhaler technique (48%) and high cost of medication (49%) were considered as major reasons for non-adherence by most physicians. Incorrect inhaler technique (66%) and nonadherence (59%) were considered the most common causes of poor asthma control.

CONCLUSIONS

There are opportunities to improve the use of diagnostic and monitoring tools for asthma. Non-adherence, incorrect inhaler technique and cost remain a challenge to achieve good asthma control. Asthma education, including correct demonstration of inhaler, can potentially help to improve inhaler adherence.

Systematic Assessment of Difficult-to-Treat Asthma: Principles and Perspectives

Difficult-to-treat asthma affects a minority of adults and children with asthma but represents a challenging mix of misdiagnosis, multimorbidity, inadequate self-management, severe airway pathobiology, and treatment complications. Management of these patients extends beyond asthma pharmacotherapy, because multiple other patient-related domains need to be addressed as well. Such complexity can hinder adequate clinical assessment even when performed in specialist practice. Systematic assessment undertaken by specialized multidisciplinary teams brings a broad range of resources to bear on patients with difficult-to-treat asthma. Although the concept of systematic assessment is not new, practices vary considerably and implementation is not universal. Nevertheless, assessment protocols are already in place in several institutions worldwide, and outcomes after such assessments have been highly encouraging. This review discusses the rationale, components, and benefits of systematic assessment, outlining its clinical utility and the available evidence for improved outcomes. It describes a range of service configurations and assessment approaches, drawing examples from severe asthma centers around the world to highlight common essential elements. It also provides a framework for establishing such services and discusses practical considerations for implementation.

Cost-effectiveness of implementing objective diagnostic verification of asthma in the United States

BACKGROUND

Asthma diagnosis in the community is often made without objective testing.

OBJECTIVE

The aim of this study was to evaluate the cost-effectiveness of implementing a stepwise objective diagnostic verification algorithm among patients with community-diagnosed asthma in the United States.

METHODS

We developed a probabilistic time-in-state cohort model that compared a stepwise asthma verification algorithm on the basis of spirometry testing and a methacholine challenge test against the current standard of care over 20 years. Model input parameters were informed from the literature and with original data analyses when required. The target population was US adults (≥15 years old) with physician-diagnosed asthma. The final outcomes were costs (in 2018 dollars) and quality-adjusted life years (QALYs), discounted at 3% annually. Deterministic and probabilistic analyses were undertaken to examine the effect of alternative assumptions and uncertainty in model parameters on the results.

RESULTS

In a simulated cohort of 10,000 adults with diagnosed asthma, the stepwise algorithm resulted in removal of the diagnosis of 3,366. This was projected to be associated with savings of $36.26 million in direct costs and a gain of 4,049.28 QALYs over 20 years. Extrapolating these results to the US population indicated an undiscounted potential savings of $56.48 billion over 20 years. The results were robust against alternative assumptions and plausible changes in values of input parameters.

CONCLUSION

Implementation of a simple diagnostic testing algorithm to verify asthma diagnosis might result in substantial savings and improvement in patients' quality of life.

Direct costs of overdiagnosed asthma: a longitudinal, population-based cohort study in British Columbia, Canada

OBJECTIVES

A current diagnosis of asthma cannot be objectively confirmed in many patients with physician-diagnosed asthma. Estimates of resource use in overdiagnosed cases of asthma are necessary to measure the burden of overdiagnosis and to evaluate strategies to reduce this burden. We assessed differences in asthma-related healthcare resource use between patients with a confirmed asthma diagnosis and those with asthma ruled out.

DESIGN

Population-based, prospective cohort study.

SETTING

Participants were recruited through random-digit dialling of both landlines and mobile phones in the province of British Columbia, Canada.

PARTICIPANTS

We included 345 individuals ≥12 years of age with a self-reported physician diagnosis of asthma. The diagnosis of asthma was reassessed at the end of 12 months of follow-up using a structured algorithm, which included a bronchodilator reversibility test, methacholine challenge test, and if necessary medication tapering and a second methacholine challenge test.

PRIMARY AND SECONDARY OUTCOME MEASURES

Self-reported annual asthma-related direct healthcare costs (2017 Canadian dollars), outpatient physician visits and medication use from the perspective of the Canadian healthcare system.

RESULTS

Asthma was ruled out in 86 (24.9%) participants. The average annual asthma-related direct healthcare costs for participants with confirmed asthma were $C497.9 (SD $C677.9) and for participants with asthma ruled out, $C307.7 (SD $C424.1). In the adjusted analyses, a confirmed diagnosis was associated with higher direct healthcare costs (relative ratio (RR)=1.60, 95% CI 1.14 to 2.22), increased rate of specialist visits (RR=2.41, 95% CI 1.05 to 5.40) and reliever medication use (RR=1.62, 95% CI 1.09 to 2.35), but not primary care physician visits (p=0.10) or controller medication use (p=0.11).

CONCLUSIONS

A quarter of individuals with a physician diagnosis of asthma did not have asthma after objective re-evaluation. These participants still consumed a significant amount of asthma-related healthcare resources. The population-level economic burden of asthma overdiagnosis could be substantial.

Over- and under-diagnosis in asthma

Asthma is extremely common with a prevalence of approximately 10% in Europe. It presents with symptoms which have a broad differential diagnosis and examination can be entirely normal. There is no agreed gold standard to diagnose asthma, and the objective tests that can aid diagnosis are often poorly available to primary care physicians. There is evidence that asthma is widely misdiagnosed. Overdiagnosis leads to unnecessary treatment and a delay in making an alternative diagnosis. Underdiagnosis risks daily symptoms, (potentially serious) exacerbations and long-term airway remodelling. An agreed standardised approach to diagnosis, with inclusion of objective measurements prior to treatment, is required to reduce misdiagnosis of asthma.

Asthma is frequently misdiagnosed. Both over- and under-diagnosis are associated with inappropriate treatment and potential patient harm. Although no gold standard diagnostic test is available, objective testing can improve diagnostic accuracy.http://ow.ly/Ej3830ohfxJ

Approaches to Asthma Diagnosis in Children and Adults

Although the hallmark features of asthma include reversible airflow obstruction, airway eosinophilia, and symptoms of recurrent wheeze associated with breathlessness and cough, it is a heterogeneous disease. The extent of the pathophysiological abnormalities are variable between patients. Despite this, until recently, asthma diagnosis had been made very simplistically predominantly from a clinical history and examination, and often a trial of medication such as short acting bronchodilators. The limitations of this approach have become increasingly apparent with evidence of inappropriate over diagnosis, under diagnosis and misdiagnosis. Although there is no gold standard single test to make a diagnosis of asthma, there are several objective tests that can be used to support the diagnosis including physiological measures such as obstructive spirometry associated with bronchodilator reversibility and airway hyperresponsiveness. In addition, non-invasive tests of airway inflammation such as exhaled nitric oxide or peripheral blood eosinophils are important to identify those with an allergic or eosinophilic phenotype. Diagnostic guidelines reflect the importance of using objective tests to support a diagnosis of asthma, however practical application in the clinic may not be straightforward. The focus of this review is to discuss the need to undertake objective tests in all patients to support asthma diagnosis and not just rely on clinical features. The advantages, challenges and limitations of performing tests of lung function and airway inflammation in the clinic, the difficulties related to training and interpretation of results will be explored, and the utility and relevance of diagnostic tests will be compared in adults and children.

Should you reassess your patient's asthma diagnosis?

Asthma may not be a permanent diagnosis in adults. A study finds that up to one-third of adults with physician-diagnosed asthma no longer had it after 5 years.

Fatal Asthma: An Audit of 30 Million Patient-Years of Health Plan Membership from 2007 to 2015

BACKGROUND

Without accurate data on deaths directly caused by asthma, prevention will be difficult.

OBJECTIVE

To determine how often asthma could be confirmed as a proximal cause of death in a large well-defined population with active health plan membership and no acute barriers to medical care.

METHODS

All deaths occurring in active Kaiser Permanente Southern California health plan members between 2007 and 2015 were identified. Asthma-coded deaths were manually audited for cause. Health care and asthma medication use in the 6 months before death were determined.

RESULTS

There were 248 (0.80 per 100,000 patient-years) unaudited asthma-coded deaths. There were only 63 (26.5%) (0.20 per 100,000 patient-years) asthma-confirmed deaths. Individuals with asthma-confirmed deaths were younger, less likely to have ever smoked, and had fewer emergency visits in the 6 months before death compared with those with asthma excluded. Individuals with asthma-confirmed deaths used preventative inhalers at very low rates. We unexpectedly found that ever inclusion in the 2016 National Committee for Quality Assurance health effectiveness data and information set (HEDIS) for persistent asthma was associated with a higher risk of all-cause early death. Individuals with asthma-confirmed deaths were also unlikely to be in the HEDIS asthma dataset in the year they died, thus not targeted for outreach.

CONCLUSIONS

Audit-confirmed fatal asthma is more likely to occur in younger, nonsmoking, individuals, using very low rates of preventive inhalers. This will be a very difficult group to prospectively identify and manage effectively. Further research into the reasons for early death after HEDIS asthma dataset inclusion is warranted.

Patterns of bronchial challenge testing in Canada

BACKGROUND

Bronchial challenge testing (BCT) measures airway hyperresponsiveness; asthma guidelines recommend using BCT when symptoms manifest despite normal spirometry. Improper application of these guidelines commonly results in the misdiagnosis of asthma. Yet, statistics concerning BCT remain largely obscure. The current paper addresses this gap and explores how various health variables may elucidate adherence to asthma guidelines and patterns of BCT across Canadian provinces.

METHODS

Using the Access to Information Act, medical financial claims for BCT (or equivalent procedures) were requested from each of the Canadian provinces and territories. Based on the available information (from provinces only), correlations between frequency of BCT claims and medical demographics (e.g., prevalence of respirologists, health expenditures) are reported.

RESULTS

Controlling for population or for people with asthma, physicians from Québec claim four times more BCT per year than those in other provinces; physicians from Alberta close to eight-fold fewer. The number of respirologists per capita and BCT per capita correlated moderately, r(132) = 0.582, p < 0.001, [95% CI 0.421, 0.716]. Excluding "outliers" (i.e., British Columbia, Alberta, and Saskatchewan) greatly strengthened this correlation, r(87) = 0.930, p < 0.001, [95% CI 0.883, 0.958].

DISCUSSION

These findings demonstrate that provinces vary in their use of BCT. This result seems to stem, at least in part, from differences in the prevalence of respirologists. Interestingly, geographic region appears to wield a strong influence; in the correlation between number of tests and number of respirologists, physicians from Western provinces (i.e., Alberta, Saskatchewan, and British Columbia) administered fewer tests than their Eastern colleagues. Given the association between inadequate application of BCT and misdiagnosis of asthma, physicians should pay special attention to the Canadian guidelines when considering an asthma diagnosis.

The role of airway hyperresponsiveness measured by methacholine challenge test in defining asthma severity in asthma-obesity syndrome

PURPOSE OF REVIEW

Asthma is a complex disease defined by chronic inflammation of the airways. In research and clinical practice measures used for diagnosis, an assessment of control and severity of asthma are varied and there exists no gold standard. To date, several studies have explored the link between obesity and asthma although the exact mechanism is not yet fully understood. A study undertaken by our research group in 2015, on the effects of weight loss on asthma severity in obese asthmatics, demonstrated that an improvement in airway hyperresponsiveness could be achieved after significant weight reduction with a weight loss program. The objective of this article is to review the current literature for the primary and secondary outcomes studied to estimate the effects of weight loss on asthma severity in adults with obesity and asthma.

RECENT FINDINGS

A review of the most recent research conducted since 2014 demonstrates that effects of weight loss on asthma severity in adults with obesity and asthma has not been the focus of majority of the studies. Apart from our study published in 2015, very few studies used airway hyperresponsiveness as the primary or secondary outcome measure. The literature reveals that significant weight loss does, however, lead to improvement in asthma severity and control in adults with obesity and asthma.

SUMMARY

The current literature suggests that improvement in lung function requires moderate to significant (5-10%) weight loss in adults with obesity and asthma. However, with a few exceptions, the majority of these studies were small and used variable and questionable asthma severity outcome measures. There is an urgent need for standardization of diagnosis of asthma, study inclusion criteria, and outcome measures to assess asthma severity in research setting. Long-term effects of weight loss interventions on asthma severity and control, in adults with obesity and asthma, also remain unanswered.

Peak flow meter with a questionnaire and mini-spirometer to help detect asthma and COPD in real-life clinical practice: a cross-sectional study

Peak flow meter with questionnaire and mini-spirometer are considered as alternative tools to spirometry for screening of asthma and chronic obstructive pulmonary disease. However, the accuracy of these tools together, in clinical settings for disease diagnosis, has not been studied. Two hundred consecutive patients with respiratory complaints answered a short symptom questionnaire and performed peak expiratory flow measurements, standard spirometry with Koko spirometer and mini-spirometry (COPD-6). Spirometry was repeated after bronchodilation. Physician made a final diagnosis of asthma, chronic obstructive pulmonary disease and others. One eighty nine patients (78 females) with age 51 ± 17 years with asthma (115), chronic obstructive pulmonary disease (33) and others (41) completed the study. "Breathlessness > 6months" and "cough > 6months" were important symptoms to detect obstructive airways disease. "Asymptomatic period > 2 weeks" had the best sensitivity (Sn) and specificity (Sp) to differentiate asthma and chronic obstructive pulmonary disease. A peak expiratory flow of < 80% predicted was the best cut-off to detect airflow limitation (Sn 90%, Sp 50%). Respiratory symptoms with PEF < 80% predicted, had Sn 84 and Sp 93% to detect OAD. COPD-6 device under-estimated FEV1 by 13 mL (95% CI: -212, 185). At a cut-off of 0.75, the FEV1/FEV6 had the best accuracy (Sn 80%, Sp 86%) to detect airflow limitation. Peak flow meter with few symptom questions can be effectively used in clinical practice for objective detection of asthma and chronic obstructive pulmonary disease, in the absence of good quality spirometry. Mini-spirometers are useful in detection of obstructive airways diseases but FEV1 measured is inaccurate.

CHRONIC LUNG DISEASES

DIFFERENTIATING CONDITIONS IN POORLY-EQUIPPED SETTINGS: A simple questionnaire and peak flow meter measurements can help doctors differentiate between asthma and chronic lung disease. In clinical settings where access to specialist equipment and knowledge is limited, it can be challenging for doctors to tell the difference between asthma and chronic obstructive pulmonary disease (COPD). To determine a viable alternative method for differentiating between these diseases, Rahul Kodgule and colleagues at the Chest Research Foundation in Pune, India, trialed a simplified version of two existing symptom questionnaires, combined with peak flow meter measurements. They assessed 189 patients using this method, and found it aided diagnosis with high sensitivity and specificity. Breathlessness, cough and wheeze were the minimal symptoms required for COPD diagnosis, while the length of asymptomatic periods was most helpful in distinguishing asthma from COPD.

Airway hyperresponsiveness to mannitol and methacholine and exhaled nitric oxide in children with asthma

OBJECTIVE

Asthma is characterized by airway hyperresponsiveness (AHR), inflammation, and obstruction. AHR to stimuli that indirectly cause bronchial smooth muscle (BSM) contractions via release of endogenous mediators is thought to better reflect airway inflammation than AHR to stimuli that act directly on BSM. Fractional exhaled nitric oxide (FeNO) is a useful parameter for noninvasive clinical airway inflammation assessments. Accordingly, this study aimed to examine the relationships of mannitol and methacholine challenge test outcomes with FeNO and the influence of inhaled corticosteroid treatment in children with asthma.

METHODS

One hundred thirty-four asthmatic children (89 males; ages: 5-17 years, median: 9 years) underwent spirometry, FeNO measurement, serum total/specific IgE testing, and blood eosinophil count. All subjects were challenged with mannitol dry powder (MDP; AridolH, Pharmaxis, Australia) and methacholine at 7-day intervals. Data of steroid-treated and steroid-naïve children were compared.

RESULTS

Positive responses to MDP and methacholine challenge tests were observed in 74.6% and 67.2% of total subject group, respectively, and 72 children had positive response to both challenge tests. The median FeNO level, response-dose ratio (RDR) of PC₂₀ methacholine, and RDR of PD₁₅ MDP were significantly higher in the steroid-treated group than in the steroid-naïve group (p < 0.001, 0.226, and 0.004, respectively). FeNO levels associated significantly with PD₁₅ MDP and RDR PD₁₅ MDP in total subject populations (p = 0.016 and 0.003, respectively); however, a significant correlation between FeNO and RDR PD₁₅ MDP was observed only in the steroid-naïve group.

CONCLUSIONS

Compared with AHR to methacholine, AHR to MDP more closely reflected the level of FeNO in steroid-naïve asthmatic children.

Addressing the misdiagnosis of asthma in adults: where does it go wrong?

INTRODUCTION

Asthma is diagnosed based on patients' respiratory symptoms of wheeze, cough, chest tightness and/or dyspnea together with physiologic evidence of variable and reversible expiratory airflow limitation. A high prevalence of overdiagnosis, underdiagnosis and misdiagnosis of adult asthma has been reported in the literature. Areas covered: Misdiagnosis of asthma in adults can occur in the community due to physicians' failure to confirm airflow limitation using spirometry, the relatively poor sensitivity of spirometry to absolutely rule in asthma, the complexity of multiple asthma phenotypes and endotypes, and the inherent day to day variability of asthma symptoms and airflow limitation. Consequences of asthma misdiagnosis to the patient and to the healthcare system include increased medication costs, increased potential side effects related to unnecessary use of medications and lost opportunities to diagnose the true cause of patients' respiratory symptoms. Expert commentary: Here we provide a review of the problem of misdiagnosis of adult asthma and suggestions for how to decrease the risk of misdiagnosis.

Cost Effectiveness of Outpatient Asthma Clinics

INTRODUCTION

Asthma clinics (AC) are hospital outpatient services specialising in the management of asthma. In this study, we analysed the impact of these clinics on asthma management and their cost effectiveness in comparison with standard outpatient services.

METHODS

A case cross-over study in which all new patients seen in the AC of Lugo in 2012 were included. The case period was defined as one year following the first visit to the AC; the control period was defined as the preceding year. We calculated changes in clinical quality indicators for asthma management, and estimated the incremental cost-effectiveness ratio (ICER) for each additional patient treated and for each quality-adjusted life year (QALY) RESULTS: The number of patients (n=83, mean age 49 ± 15.2 years; 60.2% women) managed in the AC increased from 41% to 86%. The Asthma Control Test score increased from 18.7 ± 4.6 to 22.6 ± 2.3 (p<0.05) and FEV1 increased from 81.4% ± 17.5 to 84.4% ± 16.6 (p<0.05). The number of exacerbations, hospitalisations and visits to accident and emergency fell by 75%. The number of patients given combination LABA+ICS therapy fell from 79.5% to 41%. The use of other drug therapy increased: anticholinergics, from 3.6% to 16.9%; ICS in monotherapy, from 3.6% to 45.8%; and omalizumab, from 0% to 6%. ICERs per patient managed and per QALY gained were €1,399 and €6,876, respectively (social perspective).

CONCLUSIONS

Treatment in ACs is cost-effective and beneficial in asthma management.

A case of uncontrolled severe asthma patient with coexisting carcinoid tumor presenting as pneumomediastinum

INTRODUCTION

Patients with inadequately controlled or uncontrolled asthma are at a greater risk of attacks for asthma requiring emergency room visits or hospital admissions. There is a significant correlation between the severity of the disease and the severity of exacerbations. Patients with poorly controlled asthma are at a higher risk for complications.

CASE STUDY

We present a 24-year-old aspirin-intolerant, uncontrolled asthma patient with the complication of pneumomediastinum.

RESULTS

Severe symptoms persisted after the resolution of the pneumomediastinum despite intense anti-inflammatory and anti-obstructive therapy. A bronchoscopy revealed an endobronchial lesion and she was diagnosed with a carcinoid tumor.

CONCLUSION

This case is an example of the importance of re-evaluating asthma patients who do not respond to standard medical treatment. Clinicians should be aware of the complications associated with asthma attacks such as pneumomediastinum and the possibility of a differential diagnosis that worsen asthma symptoms such as a carcinoid tumor.

Diagnostic Support for Selected Paediatric Pulmonary Diseases Using Answer-Pattern Recognition in Questionnaires Based on Combined Data Mining Applications--A Monocentric Observational Pilot Study

Background

Clinical symptoms in children with pulmonary diseases are frequently non-specific. Rare diseases such as primary ciliary dyskinesia (PCD), cystic fibrosis (CF) or protracted bacterial bronchitis (PBB) can be easily missed at the general practitioner (GP).

Objective

To develop and test a questionnaire-based and data mining-supported tool providing diagnostic support for selected pulmonary diseases.

Methods

First, interviews with parents of affected children were conducted and analysed. These parental observations during the pre-diagnostic time formed the basis for a new questionnaire addressing the parents’ view on the disease. Secondly, parents with a sick child (e.g. PCD, PBB) answered the questionnaire and a data base was set up. Finally, a computer program consisting of eight different classifiers (support vector machine (SVM), artificial neural network (ANN), fuzzy rule-based, random forest, logistic regression, linear discriminant analysis, naive Bayes and nearest neighbour) and an ensemble classifier was developed and trained to categorise any given new questionnaire and suggest a diagnosis. For estimating the diagnostic accuracy, we applied ten-fold stratified cross validation.

Results

All questionnaires of patients suffering from CF, asthma (AS), PCD, acute bronchitis (AB) and the healthy control group were correctly diagnosed by the fusion algorithm. For the pneumonia (PM) group 19/21 (90.5%) and for the PBB group 17/18 (94.4%) correct diagnoses could be reached. The program detected the correct diagnoses with an overall sensitivity of 98.8%. Receiver operating characteristics (ROC) analyses confirmed the accuracy of this diagnostic tool. Case studies highlighted the applicability of the tool in the daily work of a GP.

Conclusion

For children with symptoms of pulmonary diseases a questionnaire-based diagnostic support tool using data mining techniques exhibited good results in arriving at diagnostic suggestions. In the hands of a doctor, this tool could be of value in arousing awareness for rare pulmonary diseases such as PCD or CF.

Management of asthma and chronic obstructive pulmonary disease with combination inhaled corticosteroids and long-acting β-agonists: a review of comparative effectiveness research

The value of combination therapy with inhaled corticosteroids and long-acting β-agonists (ICS/LABA) is well recognized in the management of asthma and chronic obstructive pulmonary disease (COPD). Despite differences in the pharmacological properties between two well-established ICS/LABA products (budesonide/formoterol and fluticasone/salmeterol), data from randomized clinical trials (RCTs) and meta-analyses suggest that these two products perform similarly under RCT conditions. In contrast, a few recently reported real-world comparative effectiveness studies have suggested that there are substantial differences between ICS/LABA combination treatments in terms of clinical and healthcare outcomes in patients with asthma or COPD. The purpose of this article is to provide a brief review of the benefits, as well as the limitations, of comparative effectiveness research (CER) in the therapeutic area of asthma and COPD. We conducted a structured literature review of the current CER studies on ICS/LABA combinations in asthma and COPD. These articles were then used to illustrate the unique challenges of CER studies, providing a summary of study results and limitations. We focus particularly on difficult biases and confounding factors that may be introduced before, during, and after the initiation of therapy. Beyond being a review of these two ICS/LABA combination treatments, this article is intended to help those who wish to assess the quality of CER published projects in asthma and COPD, or guide investigators who wish to design new CER studies for chronic respiratory disease treatments.

Feasibility and effectiveness of an asthma/COPD service for primary care: a cross-sectional baseline description and longitudinal results

BACKGROUND

In 2007, an Asthma/chronic obstructive pulmonary disease (COPD) (AC) service was implemented in the North of the Netherlands to support General Practitioners (GPs) by providing advice from pulmonologists on a systematic basis.

AIMS

To evaluate the feasibility and effectiveness of this service on patient-related outcomes.

METHODS

We report baseline data on 11,401 patients and follow-up data from 2,556 patients. GPs can refer all patients with possible obstructive airway disease (OAD) to the service, which is conducted by the local laboratory. Patients are assessed in the laboratory using questionnaires and spirometry. Pulmonologists inspect the data through the internet and send the GP diagnosis and management advice.

RESULTS

A total of 11,401 patients were assessed by the service, covering almost 60% of all adult patients with projected asthma or COPD in the area. In all, 46% (n = 5,268) of the patients were diagnosed with asthma, 18% (n = 2,019) with COPD and 7% (n = 788) with the overlap syndrome. A total of 740 (7%) patients were followed up after 3 months because the GP advised them to change medication. In this group, the proportion of unstable COPD patients (Clinical COPD Questionnaire (CCQ) ⩾ 1) decreased from 63% (n = 92) at baseline to 49% (n = 72). The proportion of patients with uncontrolled asthma (Asthma Control Questionnaire (ACQ) ⩾ 1.5) decreased from 41% (n = 204) to 23% (n = 115). In all, 938 (8%) patients were followed up after 12 months. From these patients, the proportion of unstable COPD patients (CCQ ⩾ 1) decreased from 47% (n = 115) to 44% (n = 107). The proportion of patients with uncontrolled asthma (ACQ⩾1.5) decreased from 16% (n = 95) to 14% (n = 85).

CONCLUSION

The AC service assessed a considerable proportion of patients with OAD in the area, improved patients' outcomes, and is considered to be feasible and effective.

Importance of fiberoptic bronchoscopy in identifying asthma phenotypes to direct personalized therapy

PURPOSE OF REVIEW

This review summarizes the phenotyping of refractory asthma with an emphasis on how direct bronchoscopic observation and analysis of bronchoalveolar lavage (BAL), biopsy, and brushings of the airways helps direct specific personalized therapy. Additional testing used in phenotyping asthmatic patients is reviewed.

RECENT FINDINGS

Several studies and publications over the past decade have emphasized the importance of phenotyping refractory asthmatic patients to offer a better understanding of the pathobiology of disease. Bronchoscopy is a useful tool in phenotyping asthma with objective data obtained from BAL, endobronchial biopsy, and brushings. Phenotyping asthma with bronchoscopy affords personalized and successful therapy.

SUMMARY

By using fiberoptic bronchoscopy, specific asthma phenotypes can be identified: laryngopharyngeal reflux with silent aspiration; subacute bacterial infection; tissue eosinophilia; a combination of two or three of these; and nonspecific. Identifying these phenotypes and personalizing therapy with bronchoscopy leads to improved outcomes.

Effect of physical training on airway inflammation in bronchial asthma: a systematic review

Background

The majority of the global population cannot afford existing asthma pharmacotherapy. Physical training as an airway anti-inflammatory therapy for asthma could potentially be a non-invasive, easily available, affordable, and healthy treatment modality. However, effects of physical training on airway inflammation in asthma are currently inconclusive. The main objective of this review is to summarize the effects of physical training on airway inflammation in asthmatics.

Methods

A peer reviewed search was applied to Medline, Embase, Web of Science, Cochrane, and DARE databases. We included all observational epidemiological research studies and RCTs. Studies evaluating at least one marker of airway inflammation in asthmatics after a period of physical training were selected. Data extraction was performed in a blinded fashion. We decided a priori to avoid pooling of the data in anticipation of heterogeneity of the studies, specifically heterogeneity of airway inflammatory markers studied as outcome measures.

Results

From the initial 2635 studies; 23 studies (16 RCTs and 7 prospective cohort studies) were included. Study sizes were generally small (median sample size = 30). There was a reduction in C-reactive protein, malondialdehyde, nitric oxide, sputum cell counts and IgE in asthmatics with physical training. Mixed results were observed after training for fractional excretion of nitric oxide and bronchial hyperresponsiveness. The data was not pooled owing to significant heterogeneity between studies, and a funnel plot tests for publication bias were not performed because there were less than 10 studies for almost all outcome measures. Physical training intervention type, duration, intensity, frequency, primary outcome measures, methods of assessing outcome measures, and study designs were heterogeneous.

Conclusion

Due to reporting issues, lack of information and heterogeneity there was no definite conclusion; however, some findings suggest physical training may reduce airway inflammation in asthmatics.