Asthma under/misdiagnosis in primary care setting: an observational community-based study in Italy

A systematic review of the diagnostic accuracy of volatile organic compounds in airway diseases and their relation to markers of type-2 inflammation

BACKGROUND

Asthma and COPD continue to cause considerable diagnostic and treatment stratification challenges. Volatile organic compounds (VOCs) have been proposed as feasible diagnostic and monitoring biomarkers in airway diseases.

AIMS

To 1) conduct a systematic review evaluating the diagnostic accuracy of VOCs in diagnosing airway diseases; 2) understand the relationship between reported VOCs and biomarkers of type-2 inflammation; 3) assess the standardisation of reporting according to STARD and TRIPOD criteria; 4) review current methods of breath sampling and analysis.

METHODS

A PRISMA-oriented systematic search was conducted (January 1997 to December 2020). Search terms included: "asthma", "volatile organic compound(s)", "VOC" and "COPD". Two independent reviewers examined the extracted titles against review objectives.

RESULTS

44 full-text papers were included; 40/44 studies were cross-sectional and four studies were interventional in design; 17/44 studies used sensor-array technologies (e.g. eNose). Cross-study comparison was not possible across identified studies due to the heterogeneity in design. The commonest airway diseases differentiating VOCs belonged to carbonyl-containing classes (i.e. aldehydes, esters and ketones) and hydrocarbons (i.e. alkanes and alkenes). Although individual markers that are associated with clinical biomarkers of type-2 inflammation were recognised (i.e. ethane and 3,7-dimethylnonane for asthma and α-methylstyrene and decane for COPD), these were not consistently identified across studies. Only 3/44 reported following STARD or TRIPOD criteria for diagnostic accuracy and multivariate reporting, respectively.

CONCLUSIONS

Breath VOCs show promise as diagnostic biomarkers of airway diseases and for type-2 inflammation profiling. However, future studies should focus on transparent reporting of diagnostic accuracy and multivariate models and continue to focus on chemical identification of volatile metabolites.

Uncontrolled Asthma: Unmet Needs in the Management of Patients

The recent scientific research has provided clinicians with the tools for substantially upgrading the standard of care in the field of bronchial asthma. Nevertheless, satisfactory asthma control still remains an unmet need worldwide. Identifying the major determinants of poor control in different asthma severity levels represents the first step towards the improvement of the overall patients' management. The present review aims to provide an overview of the main unmet needs in asthma control and of the potential tools for overcoming the issue. Implementing a personalized medicine approach is essential, not only in terms of pharmacological treatments, biologic drugs or sophisticated biomarkers. In fact, exploring the complex profile of each patient, from his inflammation phenotype to his preferences and expectations, may help in filling the gap between the big potential of currently available treatments and the overall unsatisfactory asthma control. Telemedicine and e-health technologies may provide a strategy to both optimize disease assessment on a regular basis and enhance patients' empowerment in managing their asthma. Increasing patients' awareness as well as the physicians' knowledge about asthma phenotypes and treatment options besides corticosteroid probably represent the key and more difficult goals of all the players involved in asthma management at every level.

A systematic review of asthma case definitions in 67 birth cohort studies

BACKGROUND

Birth cohort studies are a valuable source of information about potential risk factors for childhood asthma. To better understand similarities and variations in findings between birth cohort studies, the methodologies used to measure asthma require consideration.

OBJECTIVE

To review and appraise the definitions of "asthma" used in birth cohort studies.

METHODS

A literature search, conducted in December 2017 in the MEDLINE database and birth cohort repositories, identified 1721 citations published since 1990. Information extracted included: study name, year of publication, sample size, sample age, prevalence of asthma (%), study region, source of information about asthma, measured outcome, and asthma case definition. A meta-analysis evaluated whether asthma prevalence in cohorts from Europe and North America varied by the studies' definition of asthma and by their data sources.

RESULTS

The final review included 67 birth cohorts, of which 48 (72%) were from Europe, 14 (21%) from North America, 3 (5%) from Oceania, 1 (1%) from Asia and 1 (1%) from South America. We identified three measured outcomes: "asthma ever", "current asthma", and "asthma" without further specification. Definitions of "asthma ever" were primarily based upon an affirmative parental response to the question whether the child had ever been diagnosed with asthma by a physician. The most frequently used definition of "current asthma" was "asthma ever" and either asthma symptoms or asthma medications in the last 12 months. This definition of "current asthma" was used in 16 cohorts. There was no statistically significant difference in the pooled asthma prevalence in European and North American cohorts that used questionnaire alone versus other data sources to classify asthma.

CONCLUSION

There is substantial heterogeneity in childhood asthma definitions in birth cohort studies. Standardisation of asthma case definitions will improve the comparability and utility of future cohort studies and enable meta-analyses.

Diagnostic practices for patients with shortness of breath and presumed obstructive airway disorders: a cross-sectional analysis

BACKGROUND

Dyspnea is a common symptom that has many causes, including obstructive airway disorders. We sought to examine previous diagnosis of obstructive airway disorders and other conditions in patients receiving treatment with inhaled medications for shortness of breath in a community setting.

METHODS

This cross-sectional study included consecutive patients aged 18 years and older receiving treatment for shortness of breath with inhaled medications for a minimum of 6 months. Study participants were recruited through community pharmacies in Edmonton and Saskatoon, Canada, between February 2009 and February 2012. Previous diagnosis of obstructive airway disorders by a primary care provider was assessed by patient self-report and review of health records. We conducted an assessment (as per guidelines from the American Thoracic Society and the European Respiratory Society), including pulmonary function tests; diagnoses were adjudicated by an expert physician panel (2 respirologists and 1 emergency physician). The agreement between diagnoses derived from pulmonary function tests and diagnoses from primary care providers was evaluated.

RESULTS

A total of 328 patients (median age 50 yr, 57.3% female) underwent assessment; 134 (40.9%) of patients reported ever having a pulmonary function test performed. After adjudication, 138 (42.1%) were diagnosed with asthma only, 86 (26.2%) with chronic obstructive pulmonary disease only and 11 (3.4%) with both. Some patients (93, 28.4%) had no evidence of obstructive airway disorders and 20 (6.1%) had evidence of other conditions that cause shortness of breath, such as heart failure and pulmonary hypertension. Overall, 62 (18.9%) patients could not be assigned a diagnosis.

INTERPRETATION

In a group of community-based patients with shortness of breath being treated with inhalers, less than half ever had pulmonary function tests performed, and a considerable proportion had no evidence of lung disease or other conditions. These findings highlight the need for confirmatory testing, including pulmonary function tests, before prescribing inhalers for patients with presumed obstructive airway disorders.

Therapeutic and prophylactic deletion of IL-4Ra-signaling ameliorates established ovalbumin induced allergic asthma

Background

Allergic asthma is a chronic inflammatory airway disease driven predominantly by a T_H2 immune response to environmental allergens. IL‐4Rα‐signaling is essential for driving T_H2‐type immunity to allergens. Anti‐T_H2 therapies have the potential to effectively reduce airway obstruction and inflammation in allergic asthma.

Objective

We investigated potential therapeutic effects of selective inhibition of this pathway in mice with established allergic airway disease. We further investigated whether IL‐4Rα disruption in systemically sensitized mice can prevent the onset of the disease.

Methods

We used Rosa^creERT2IL‐4Rα^−/lox mice, a tamoxifen (TAM)‐inducible IL‐4Rα knockdown model to investigate the role of IL‐4/IL‐13 signaling prior to the onset of the disease and during the effector phase in the ovalbumin‐induced allergic airway disease.

Results

Inducible deletion of IL‐4Rα demonstrated therapeutic effects, on established allergic airway disease, and prevented the development of ovalbumin‐induced airway hyperreactivity, eosinophilia, and goblet cell metaplasia in allergen‐sensitized mice. Interestingly, IL‐4Rα knockdown after allergic sensitization did not induce T_H17, a neutrophilic inflammatory response as observed in global IL‐4Rα‐deficient mice after intranasal allergen challenge.

Conclusion

Abrogation of IL‐4Rα signaling after allergic sensitization would have significant therapeutic benefit for T_H2‐type allergic 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.

Ability of Exhaled Nitric Oxide to Discriminate for Airflow Obstruction Among Frequent Exacerbators of Clinically Diagnosed Asthma

OBJECTIVE

Fraction of exhaled nitric oxide (FE_NO) has been proposed as a non-invasive biomarker for allergic inflammation seen in asthma. Many asthmatics in clinical practice have never had spirometry and recent data report misdiagnoses in patients with physician diagnosed (PD) asthma. The aim of this study was to assess the ability of FE_NO to discriminate between those with and without airflow obstruction (AO) among patients with PD-asthma.

METHODS

Frequent exacerbators of PD-asthma (with 2 or more asthma exacerbations leading to emergency room visit or hospitalization within last 12 months) were enrolled. All patients underwent diagnostic evaluations including spirometry, FE_NO testing and serum immunoglobulin (IgE) and eosinophils. Serial spirometry and methacholine challenge testing (MCT) were performed as indicated. AO was defined by a decreased FEV1/FVC ratio (< 70% and/or < LLN), or a positive MCT.

RESULTS

Of the 222 patients with PD-asthma, AO was found in 136 (vs. 86 without AO). 81.6% of patients with AO and 66.2% without AO completed FE_NO testing. There was no significant difference in the mean FE_NO levels among patients with or without AO (40.8 vs. 30.4 ppb, P = 0.10). Likewise, there was no difference in the serum IgE levels and serum eosinophils.

CONCLUSIONS

Our analyses suggest that FE_NO levels do not help discriminate between those with and without AO in patients with PD-asthma. Patients who experience symptoms of asthma may have elevated FE_NO levels above the suggested cut points of 20-25 ppb. Objective confirmation of AO should be considered in all patients with PD-asthma, irrespective of FE_NO levels.

Variations in the prevalence of childhood asthma and wheeze in MeDALL cohorts in Europe

While there is evidence for variations in prevalence rates of childhood wheeze and asthma between countries, longitudinal, individual-level data are needed to understand these differences. The aim of this study was to examine variations in prevalence rates of childhood asthma, wheeze and wheeze with asthma in Europe.

We analysed datasets from 10 MeDALL (Mechanisms of the Development of ALLergy) cohorts in eight countries, representing 26 663 children, to calculate prevalence rates of wheeze and asthma by child age and wheeze with asthma at age 4 years. Harmonised variables included outcomes parent-reported wheeze and parent-reported doctor-diagnosed asthma, and covariates maternal education, parental smoking, pets, parental asthma, doctor-diagnosed allergic rhinitis, doctor-diagnosed eczema and wheeze severity.

At age 4 years, asthma prevalence varied from 1.72% in Germany to 13.48% in England and the prevalence of wheeze varied from 9.82% in Greece to 55.37% in Spain. Adjusted estimates of the proportion of 4-year-old children with wheeze diagnosed with asthma remained highest in England (38.14%, 95% CI 31.38–44.90%) and lowest in Spain (15.94%, 95% CI 6.16–25.71%).

The large differences in prevalence rates of asthma, wheeze and wheeze with asthma at age 4 years between European cohorts may indicate that childhood asthma is more readily diagnosed in some countries while going unrecognised elsewhere.

Large variations in childhood wheeze across Europe do not match large variations in diagnosed childhood asthmahttp://ow.ly/eJQk30aPInr

Appropriateness in allergic respiratory diseases health care in Italy: definitions and organizational aspects

In a historical period in which sustainability of the National Health Service is mandatory because of the international economical situation, the limited available resources at national level and the tendency of passing from a “population medicine” model towards the concept of “individualized medicine”, the debate on appropriateness of medical and surgical procedures is of central importance. The choosing wisely campaign, started in United States in 2012 and then spread all over the world, tries to summarize which are the most inappropriate procedures for each medical and surgical speciality; as far as allergic respiratory diseases, the most relevant Italian societies and the American Academy defined the allergological procedures with the highest probability of inappropriateness. In Italy, a recent decree of the Ministry of Health defined a list of more than 200 procedures that will be considered as inappropriate in certain conditions; many of these procedures concern allergology, including allergic respiratory diseases. In this commentary we discuss the above mentioned decree and the concept of appropriateness in the field of allergic respiratory diseases, trying to figure out some practical considerations based on the current health resources available in the field of allergology in Italy.