Underdiagnosed asthma in South Australia

Clinical inertia in asthma

Despite advances in pharmaceutical treatment in recent years, a relatively high proportion of patients with asthma do not have adequate asthma control, causing chronic disability, poor quality of life, and multiple emergency department visits and hospitalizations. A multifaceted approach is needed to overcome the problems with managing asthma, and clinical inertia (CI) is a crucial concept to assist with this approach. It divides clinical inertia into three main categories, which include healthcare provider-related, patient-related, and healthcare system-related CI. The strategies to overcome these CI are complex, and the M-GAP approach, which combines a multidisciplinary approach, dissemination of guidelines, utilization of applications, and development and promotion of low-cost prescriptions, will help clinicians.

Risk Factors for Abnormal Small Airway Function Indicators in Nasal Polyp Patients with and without Asthma

INTRODUCTION

Small airway dysfunction (SAD) is associated with type 2 inflammation in patients who have non-asthmatic chronic rhinosinusitis with nasal polyps (CRSwNPs); however, the risk factors for abnormal small airway function indicators in CRSwNP patients with and without asthma remain unclear.

METHODS

We retrospectively analyzed 41 asthmatic and 109 non-asthmatic CRSwNP patients. Clinical characteristics were compared between groups, correlations between small airway function and clinical parameters were calculated, and independent risk factors for every small airway indicator were identified in each group.

RESULTS

Asthmatic CRSwNP patients had significantly reduced small airway function, and the proportion of patients with SAD was higher in asthmatic CRSwNP patients (65.85%) than in patients without asthma (9.17%). With regard to specific airway function indicators, age and a patient's blood eosinophil (%) were identified as independent risk factors for lower FEF50% %pred and FEF25-75% pred, with age being an independent risk factor for FEF75% %pred in asthmatic CRSwNP patients. In non-asthmatic CRSwNP patients, allergic rhinitis comorbidity was found to be an independent risk factor for FEF50% %pred, FEF75% %pred, and FEF25-75% %pred.

CONCLUSION

Physicians should pay greater attention to risk factors for abnormal small airway function indicators in patients with CRSwNPs to prevent the occurrence of SAD.

Key recommendations for primary care from the 2022 Global Initiative for Asthma (GINA) update

The Global Initiative for Asthma (GINA) was established in 1993 by the World Health Organization and the US National Heart Lung and Blood Institute to improve asthma awareness, prevention and management worldwide. GINA develops and publishes evidence-based, annually updated resources for clinicians. GINA guidance is adopted by national asthma guidelines in many countries, adapted to fit local healthcare systems, practices, and resource availability. GINA is independent of industry, funded by the sale and licensing of its materials. This review summarizes key practical guidance for primary care from the 2022 GINA strategy report. It provides guidance on confirming the diagnosis of asthma using spirometry or peak expiratory flow. GINA recommends that all adults, adolescents and most children with asthma should receive inhaled corticosteroid (ICS)-containing therapy to reduce the risk of severe exacerbations, either taken regularly, or (for adults and adolescents with "mild" asthma) as combination ICS-formoterol taken as needed for symptom relief. For patients with moderate-severe asthma, the preferred regimen is maintenance-and-reliever therapy (MART) with ICS-formoterol. Asthma treatment is not "one size fits all"; GINA recommends individualized assessment, adjustment, and review of treatment. As many patients with difficult-to-treat or severe asthma are not referred early for specialist review, we provide updated guidance for primary care on diagnosis, further investigation, optimization and treatment of severe asthma across secondary and tertiary care. While the GINA strategy has global relevance, we recognize that there are special considerations for its adoption in low- and middle-income countries, particularly the current poor access to inhaled medications.

Patient and physician factors associated with symptomatic undiagnosed asthma or COPD

BACKGROUND

It remains unclear why some symptomatic individuals with asthma or COPD remain undiagnosed. Here, we compare patient and physician characteristics between symptomatic individuals with obstructive lung disease (OLD) who are undiagnosed and individuals with physician-diagnosed OLD.

METHODS

Using random-digit dialling and population-based case finding, we recruited 451 participants with symptomatic undiagnosed OLD and 205 symptomatic control participants with physician-diagnosed OLD. Data on symptoms, quality of life and healthcare utilisation were analysed. We surveyed family physicians of participants in both groups to elucidate differences in physician practices that could contribute to undiagnosed OLD.

RESULTS

Participants with undiagnosed OLD had lower mean pre-bronchodilator forced expiratory volume in 1 s percentage predicted compared with those who were diagnosed (75.2% versus 80.8%; OR 0.975, 95% CI 0.963-0.987). They reported greater psychosocial impacts due to symptoms and worse energy and fatigue than those with diagnosed OLD. Undiagnosed OLD was more common in participants whose family physicians were practising for >15 years and in those whose physicians reported that they were likely to prescribe respiratory medications without doing spirometry. Undiagnosed OLD was more common among participants who had never undergone spirometry (OR 10.83, 95% CI 6.18-18.98) or who were never referred to a specialist (OR 5.92, 95% CI 3.58-9.77). Undiagnosed OLD was less common among participants who had required emergency department care (OR 0.44, 95% CI 0.20-0.97).

CONCLUSIONS

Individuals with symptomatic undiagnosed OLD have worse pre-bronchodilator lung function and present with greater psychosocial impacts on quality of life compared with their diagnosed counterparts. They were less likely to have received appropriate investigations and specialist referral for their respiratory symptoms.

Economic evaluation of integrated services for non-communicable diseases and HIV: costs and client outcomes in rural Malawi

OBJECTIVE

To evaluate the costs and client outcomes associated with integrating screening and treatment for non-communicable diseases (NCDs) into HIV services in a rural and remote part in southeastern Africa.

DESIGN

Prospective cohort study.

SETTING

Primary and secondary level health facilities in Neno District, Malawi.

PARTICIPANTS

New adult enrollees in Integrated Chronic Care Clinics (IC3) between July 2016 and June 2017.

MAIN OUTCOME MEASURES

We quantified the annualised total and per capita economic cost (US$2017) of integrated chronic care, using activity-based costing from a health system perspective. We also measured enrolment, retention and mortality over the same period. Furthermore, we measured clinical outcomes for HIV (viral load), hypertension (controlled blood pressure), diabetes (average blood glucose), asthma (asthma severity) and epilepsy (seizure frequency).

RESULTS

The annualised total cost of providing integrated HIV and NCD care was $2 461 901 to provide care to 9471 enrollees, or $260 per capita. This compared with $2 138 907 for standalone HIV services received by 6541 individuals, or $327 per capita. Over the 12-month period, 1970 new clients were enrolled in IC3, with a retention rate of 80%. Among clients with HIV, 81% achieved an undetectable viral load within their first year of enrolment. Significant improvements were observed among clinical outcomes for clients enrolled with hypertension, asthma and epilepsy (p<0.05, in all instances), but not for diabetes (p>0.05).

CONCLUSIONS

IC3 is one of the largest examples of fully integrated HIV and NCD care. Integrating screening and treatment for chronic health conditions into Malawi's HIV platform appears to be a financially feasible approach associated with several positive clinical outcomes.

Chronic respiratory disease in adult outpatients in three African countries: a cross-sectional study

BACKGROUND: The greatest burden of chronic respiratory disease is in low- and middle-income countries, with recent population-based studies reporting substantial levels of obstructive and restrictive lung function.OBJECTIVE: To characterise the common chronic respiratory diseases encountered in hospital outpatient clinics in three African countries.METHODS This was a cross-sectional study of consecutive adult patients with chronic respiratory symptoms (>8 weeks) attending hospital outpatient departments in Ethiopia, Kenya and Sudan. Patients were assessed using a respiratory questionnaire, spirometry and chest radiography. The diagnoses of the reviewing clinicians were ascertained.RESULT: A total of 519 patients (209 Kenya, 170 Ethiopia, 140 Sudan) participated; the mean age was 45.2 years (SD 16.2); 53% were women, 83% had never smoked. Reviewing clinicians considered that 36% (95% CI 32-40) of patients had asthma, 25% (95% CI 21-29) had chronic bronchitis, 8% (95% CI 6-11) chronic obstructive pulmonary disease (COPD), 5% (95% CI 4-8) bronchiectasis and 4% (95% CI 3-6) post-TB lung disease. Spirometry consistent with COPD was present in 35% (95% CI 30-39). Restriction was evident in 38% (95% CI 33-43). There was evidence of sub-optimal diagnosis of asthma and COPD.CONCLUSION: In Ethiopia, Kenya and Sudan, asthma, COPD and chronic bronchitis account for the majority of diagnoses in non-TB patients with chronic respiratory symptoms. The suboptimal diagnosis of these conditions will require the widespread use of spirometry.

Asthma diagnosis: into the fourth dimension

Asthma is the most common chronic respiratory disease in the UK; however, the misdiagnosis rate is substantial. The lack of consistency in national guidelines and the paucity of data on the performance of diagnostic algorithms compound the challenges in asthma diagnosis. Asthma is a highly rhythmic disease, characterised by diurnal variability in clinical symptoms and pathogenesis. Asthma also varies day to day, seasonally and from year to year. As much as it is a hallmark for asthma, this variability also poses significant challenges to asthma diagnosis. Almost all established asthma diagnostic tools demonstrate diurnal variation, yet few are performed with standardised timing of measurements. The dichotomous interpretation of diagnostic outcomes using fixed cut-off values may further limit the accuracy of the tests, particularly when diurnal variability straddles cut-off values within a day, and careful interpretation beyond the 'positive' and 'negative' outcome is needed. The day-to-day and more long-term variations are less predictable and it is unclear whether performing asthma diagnostic tests during asymptomatic periods may influence diagnostic sensitivities. With the evolution of asthma diagnostic tools, home monitoring and digital apps, novel strategies are needed to bridge these gaps in knowledge, and circadian variability should be considered during the standardisation process. This review summarises the biological mechanisms of circadian rhythms in asthma and highlights novel data on the significance of time (the fourth dimension) in asthma diagnosis.

Spirometric Changes in Bronchodilation Tests as Predictors of Asthma Diagnosis and Treatment Response in Patients with FEV1 ≥ 80% Predicted

BACKGROUND

Many patients with mild asthma are undiagnosed and untreated due to the low diagnostic sensitivity of bronchodilation test (BDT).

OBJECTIVE

To investigate whether airway reversibility in BDT and fractional exhaled nitric oxide (Feno) can predict the response to antiasthma therapy (RAT) in patients with suspected asthma.

METHODS

This open-label, prospective cohort study included patients with chronic recurrent asthma symptoms, normal FEV₁, and negative BDT results. Inhaled corticosteroids and long-acting β agonists were given for 4 weeks. A positive RAT was defined as improved symptoms and an increase of more than 200 mL in FEV₁ after inhaled corticosteroid/long-acting β agonist treatment. Lung tissues from another 19 patients who underwent pneumectomy for lung nodules were also analyzed.

RESULTS

Of 110 patients recruited, 102 completed the study. Patients in the positive RAT group had a higher Feno and greater absolute (Δ) and percent (Δ%) improvements in forced vital capacity, FEV₁, and forced expiratory flows (FEFs) in BDT than in the negative RAT group. The area under the curves of Feno, ΔFEV₁%, ΔFEF_25-75% (percent improvement in FEF at 25%-75% of forced vital capacity), and ΔFEF₇₅% (percent improvement in FEF at 75% of forced vital capacity) for positive RAT were 0.703, 0.824, 0.736, and 0.710, with cutoff values of 33 parts per billion and 3.50%, 15.26%, and 26.04%, respectively. A joint model of Feno and ΔFEV₁% increased the area under the curve to 0.880. Inflammatory cytokines were higher in the lung tissues of patients with predicted positive RAT than in those with predicted negative RAT.

CONCLUSIONS

ΔFEV₁% in BDT together with Feno predicted a positive RAT and an asthma diagnosis in patients with a normal FEV₁ and negative BDT. Evidence of pathological changes increases the credibility of the predictive model.

Clinical Differences between Early- and Late-Onset Asthma: A Population-Based Cross-Sectional Study

Background

Limited information exists about the nature of late-onset asthma (LOA) without medication intervention when compared to early-onset asthma (EOA). Our goal was to understand how EOA and LOA affect clinical and pathophysiological features.

Methods

A population-based cross-sectional study was carried out in Zhongshan Hospital (Shanghai, China). EOA and LOA were based on age of diagnosis (before and after age 40 years, respectively). Clinical variables were collected with an emphasis on allergic features, analyzed, related, and compared using one-way ANOVA or Kruskal-Wallis test. Correlations between blood basophils and clinical data were evaluated by Spearman's rank test. Statistical analyses were conducted with SPSS v24.0.

Results

Of a total of 12,760 adults with cough, sputum, or chest tightness, 90 subjects with EOA (mean age ± standard deviation (SD):28.73 ± 5.89), 111 with LOA (mean age ± SD: 60.25 ± 9.85), and 106 with chronic obstructive pulmonary disease (COPD) (mean age ± SD: 61.58 ± 10.95) were selected. FEV₁/FVC (%), FEV₁% predicted, and FVC% predicted were all significantly lower in LOA compared to EOA (p < 0.01). The values of post-bronchodilator FEV₁ in bronchodilator reversibility testing were higher in the LOA and EOA groups compared to subjects with COPD (p < 0.01). Among allergic features, mite sensitization was most common in EOA patients, followed by LOA and COPD, whereas mold sensitization was more prevalent in LOA than EOA. Moreover, blood eosinophils were a typical feature of asthma in both EOA and LOA compared to COPD and controls (p < 0.01), and there were no differences in blood neutrophils in LOA compared to controls. Interestingly, blood basophils were increased in both EOA (p < 0.01) and LOA (p < 0.05) compared to COPD and controls. This variable correlated with eosinophils in EOA (r = 0.549, p=0.002) but not in LOA.

Conclusion

LOA is a distinct clinical entity from EOA. In LOA, atopy was less frequent and spirometry values were lower when compared to EOA. In EOA, blood basophils and eosinophils were significantly correlated owing to pathophysiological differences between the two forms of the disease.

Oral prednisolone for acute lower respiratory tract infection in clinically unrecognised asthma: an exploratory analysis of the Oral Steroids for Acute Cough (OSAC) randomised controlled trial

Background

Acute lower respiratory tract infection (ALRTI) is often treated in primary care with antibiotics. The recent Oral Steroids for Acute Cough (OSAC) randomised controlled trial (RCT) showed corticosteroids were not an effective alternative in adults without a diagnosis of asthma with ALRTI.

Aim

To investigate if corticosteroids are beneficial for ALRTI in patients with unrecognised asthma.

Design & setting

An exploratory analysis was undertaken of the primary care OSAC trial.

Method

A subgroup analysis was performed in patients who responded ‘yes’ to the following International Primary Care Airways Group (IPCAG) question: did you have wheeze and/or at least two of nocturnal cough or chest tightness or dyspnoea in the past year. Sensitivity analyses were carried out on those who answered ‘yes’ to wheeze and at least two of the nocturnal symptoms. The primary outcomes were as follows: duration of cough (0–28 days, minimum clinically important difference [MCID] of 3.79 days) and mean symptom severity score (range 0–6; MCID 1.66 units).

Results

In total, 40 (10%) patients were included in the main analysis: mean age 49 years (standard deviation [SD] = 17.9), 52% male. Median cough duration was 3 days in both prednisolone (interquartile range [IQR] = 2–6 days) and placebo (IQR = 1–6 days) groups (adjusted hazard ratio [HR] = 1.10; 95% confidence interval [CI] = 0.47 to 2.54; P = 0.83), equating to 0.24 days longer in the prednisolone group (95% CI = 1.23 days shorter to 2.88 days longer). Mean symptom severity difference was –0.14 (95% CI = –0.78 to 0.49; P=0.65) comparing prednisolone with placebo. Similar findings were found in the sensitivity analysis.

Conclusion

No evidence was found to support the use of corticosteroids for ALRTI in patients with clinically unrecognised asthma. Clinicians should not use the IPCAG questions to target oral corticosteroid treatment in patients with ALRTI.

Population-based case-finding to identify subjects with undiagnosed asthma or COPD

BACKGROUND

∼5-10% of adults may have undiagnosed airflow obstruction. The objective of this study was to develop a population-based case-finding strategy to assess the prevalence of undiagnosed airflow obstruction (asthma or COPD) amongst adults with respiratory symptoms in Canada.

METHODS

Adults without a previous history of asthma, COPD or lung disease were recruited using random digit-dialling and asked if they had symptoms of dyspnoea, cough, sputum or wheeze within the past 6 months. Those who answered affirmatively completed the Asthma Screening Questionnaire (ASQ), COPD-Diagnostic Questionnaire (COPD-DQ) and COPD Assessment Test (CAT). Those with an ASQ score of ≥6 or a COPD-DQ score of ≥20 underwent pre- and post-bronchodilator spirometry to diagnose asthma or COPD.

RESULTS

12 117 individuals were contacted at home and assessed for study eligibility. Of the 1260 eligible individuals, 910 (72%) enrolled and underwent spirometry. Ultimately, 184 subjects (20% of those enrolled) had obstructive lung disease (73 asthma and 111 COPD). Individuals found to have undiagnosed asthma or COPD had more severe respiratory symptoms and impaired quality of life compared with those without airflow obstruction. The ASQ, COPD-DQ, and CAT had ROC areas for predicting undiagnosed asthma or COPD of 0.49, 0.64 and 0.56, respectively. Four descriptive variables (age, BMI, sex and pack-years smoked) produced better receiver operating characteristic (ROC) values than the questionnaires (ROC area=0.68).

CONCLUSION

20% of randomly selected individuals who report respiratory symptoms in Canada have undiagnosed airflow obstruction due to asthma or COPD. Questionnaires could exclude subjects at low risk but lack the ability to accurately find subjects with undiagnosed disease.

Epidemiology of asthma and associated factors in an urban Pakistani population: adult asthma study-Karachi

BACKGROUND

This study was conducted in order to determine the prevalence of asthma and associated risk factors in the adult population of Karachi, Pakistan.

METHODS

This multi-stage, cross-sectional survey was conducted from May 2014-August 2015; comprising 1629 adults in 75 randomly selected clusters in Karachi, Pakistan. Definitions included: 'self-reported asthma', 'reversibility in FEV1' and 'respiratory symptoms and reversibility in FEV1'.

RESULTS

Prevalence of asthma was 1.8% (self-reported) (95% CI: 1.0-2.6), 11.3% (reversibility in FEV1) (95% CI: 9.4-13.3) and 6.6% (symptoms and reversibility in FEV1) (95% CI: 5.1-8.1). Asthmatics were more likely to belong to the age group ≥38 years according to 'reversibility in FEV1' and 'respiratory symptoms and reversibility in FEV1' (AOR: 1.9, 95% CI: 1.2-3.3) and (AOR: 2.1, 95% CI: 1.1-4.2), respectively. Asthmatics were more likely to report history of allergies (AOR: 1.9, 95% CI: 1.2-2.9) and (AOR: 2.8, 95% CI: 1.7-4.8); and were exposed to environmental tobacco smoke (AOR: 1.6, 95% CI: 1.1-2.5) and (AOR: 1.9, 95% CI: 1.1-3.3) according to 'reversibility in FEV1' and 'respiratory symptoms and reversibility in FEV1', respectively. Asthmatics were more likely to report pack years of smoking ≥5 (AOR: 2.3, 95% CI: 1.1-4.7) according to 'respiratory symptoms and reversibility in FEV1'.

CONCLUSION

This study reports a high prevalence of asthma among Pakistani adults and calls for developing appropriate public health policies for prevention and control of asthma in the country. Further studies should be conducted to determine the national prevalence as well as follow-up studies to identify preventable causes for adult asthma.

Asthma in the Elderly

The older population has seen the greatest increase in the prevalence of current asthma in recent years. Asthma may begin at any age and when it occurs at an advanced as opposed to a young age, it is often nonatopic, severe, and unremitting. Unfortunately, geriatric-specific guidelines are not available for the diagnosis and treatment of asthma. However, with objective monitoring, avoidance of asthma triggers, appropriate pharmacotherapy, and patient education, the disease can be managed successfully.

BIRC3 single nucleotide polymorphism associate with asthma susceptibility and the abundance of eosinophils and neutrophils

BACKGROUND AND OBJECTIVE

Aberrant apoptosis is a disease susceptibility mechanism relevant for asthma, whereby fragility of the airway epithelium and enhanced survival of inflammatory cells, contributes to its pathogenesis and prolongation. Cellular Inhibitor of Apoptosis Proteins (cIAP) suppress apoptosis, and participate in the immune response. In this study, single nucleotide polymorphisms (SNP) in the BIRC2 (codes cIAP1) and BIRC3 (cIAP2) genes were evaluated for an association with asthma.

METHODS

Caucasian asthmatic (n = 203) and control (n = 198) subjects were selected from participants in the North West Adelaide Health Study. SNPs (n = 9) spanning the consecutively positioned BIRC2 and BIRC3 genes, were selected using a haplotype tagging approach. Alleles and haplotype associations were analysed by logistic regression, assuming an additive genetic model, and adjusted for gender and atopy.

RESULTS

The frequency of the minor allele for the BIRC3 SNP rs3460 was significantly lower in asthmatics compared to the control cases (P = 0.046). BIRC3 SNPs rs7928663 and rs7127583 associated with a reduction in eosinophil and neutrophil abundance when assessed across the study population (multivariate P values = 0.002, and 0.005, respectively). Further, the frequency of a haplotype tagged by rs3460, rs7928663 and rs7127583 was reduced in the asthma sub group (P = 0.05), while the presence of the major allele for rs7928663 associated with an increased load of circulating eosinophils and neutrophils (multivariate P value = 0.001).

CONCLUSIONS

Polymorphisms in the BIRC3 gene, but not BIRC2, are associated with a protective effect with regards to asthma susceptibility, and a reduced load of inflammatory cells.

[Dyspnea in airway and pulmonary diseases]

The subjective perception of pulmonary dyspnea varies based on behavioral and physiological responses. Acute pulmonary dyspnea is the most common symptom of diseases of the airways and the lungs and the differential diagnosis includes harmless causes, such as lack of training as well as acute life-threatening diseases, such as thromboembolism, obstruction of the upper or lower airway, pneumonia, pulmonary hemorrhage and pneumothorax. Most cases of chronic pulmonary dyspnea result from asthma, chronic obstructive pulmonary disease (COPD), pulmonary arterial hypertension, pulmonary fibrosis and pleural disorders. Listening to the patient's "language of dyspnea" may already provide indications for the diagnosis. Initial testing includes chest radiography, spirometry, complete blood count and the basic metabolic panel. Measurement of brain natriuretic peptide levels may help to exclude heart failure in COPD and D-dimer testing may help rule out pulmonary embolisms. Computed tomography of the chest is the most appropriate imaging procedure for diagnosing pulmonary embolism and interstitial lung disease. To diagnose pulmonary arterial hypertension echocardiography and right heart catheterization may be necessary.

Diagnostic accuracy of respiratory diseases in primary health units

Respiratory diseases are responsible for about a fifth of all deaths worldwide and its prevalence reaches 15% of the world population. Primary health care (PHC) is the gateway to the health system, and is expected to resolve up to 85% of health problems in general. Moreover, little is known about the diagnostic ability of general practitioners (GPs) in relation to respiratory diseases in PHC. This review aims to evaluate the diagnostic ability of GPs working in PHC in relation to more prevalent respiratory diseases, such as acute respiratory infections (ARI), tuberculosis, asthma and chronic obstructive pulmonary disease (COPD). 3,913 articles were selected, totaling 30 after application of the inclusion and exclusion criteria. They demonstrated the lack of consistent evidence on the accuracy of diagnoses of respiratory diseases by general practitioners. In relation to asthma and COPD, studies have shown diagnostic errors leading to overdiagnosis or underdiagnosis depending on the methodology used. The lack of precision for the diagnosis of asthma varied from 54% underdiagnosis to 34% overdiagnosis, whereas for COPD this ranged from 81% for underdiagnosis to 86.1% for overdiagnosis. For ARI, it was found that the inclusion of a complementary test for diagnosis led to an improvement in diagnostic accuracy. Studies show a low level of knowledge about tuberculosis on the part of general practitioners. According to this review, PHC represented by the GP needs to improve its ability for the diagnosis and management of this group of patients constituting one of its main demands.

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.

Prevalence, risk factors and underdiagnosis of asthma and wheezing in adults 40 years and older: A population-based study

OBJECTIVE

There are differences in the prevalence and risk factors of asthma around the world. The epidemiological situation of adults 40 years and older is not well established. Our aim was to determine the prevalence, underdiagnosis and risk factors of asthma and wheezing in adults in Colombia.

METHODS

A cross-sectional, population-based study including 5539 subjects from 40 to 93 years selected by a probabilistic sampling technique in five cities was conducted.

MEASUREMENTS

respiratory symptoms and risk factors questionnaire and spirometry.

DEFINITIONS

(a) Wheezing: Affirmative answer to the question "have you ever had two or more attacks of "wheezes" causing you to feel short of breath?" (b) Asthma: Wheezing definition and FEV1/FVC post-bronchodilator ≥ 70%. (c) Underdiagnosis: Asthma definition without a physician-diagnosis. Logistic regression was used for exploring risk factors.

RESULTS

Prevalence of asthma was 9.0% (95% CI: 8.3-9.8) and wheezing 11.9% (95% CI: 11.0-12.8). Asthma underdiagnosis was 69.9% and increased to 79.0% in subjects 64 years or older. The risk factors related to asthma and/or wheezing were: living in Bogota or Medellin, female gender, first degree relative with asthma, respiratory disease before 16 years of age, obesity, no education, indoor wood smoke exposure and occupational exposure to dust particles, gases or fumes.

CONCLUSION

We described the epidemiologic situation of asthma in adults 40 years and older in Colombia. In addition to some recognized risk factors, our data supports the association of indoor wood smoke and occupational exposures with asthma and wheezing. Underdiagnosis of asthma in adults was high, particularly in older subjects.

Preconception and prenatal environmental factors associated with communication impairments in 9 year old children using an exposome-wide approach

Although speech and language deficits are common in children and strongly associated with poor educational and social outcomes, little attention has been paid to the antecedents. In this study we used the information from the Avon Longitudinal Study of Parents and Children to examine preconception and prenatal environmental risk factors that were related to communication difficulties in children using the Children’s Communication Checklist (CCC). We used an exposome-wide approach to identify environmental factors univariably associated with the CCC. Taking account of the False Discovery rate, we used a P value of 0.000157 to identify 621 of 3855 items tested. These were then subjected to a series of stepwise linear regression analyses, firstly within 10 domains: personal characteristics, health, development, education, socio-economic variables, lifestyle, home and social environments, life events and chemical and other exposures; and then with the predictive variables from each domain. The final model consisted of 19 variables independently associated with the communication scale. These variables suggested 6 possible mechanisms: stressors primarily associated with socio-economic disadvantage although other lifestyle choices such as a social network of family or friends can ameliorate these effects; indicators of future parenting skills primarily associated with aspects of parental personality; aspects of the home environment; poor maternal health with a novel finding concerning maternal hearing loss; and maternal education which was partially mediated by the child’s IQ. Finally, there may be a mechanism via the maternal diet in pregnancy in particular the consumption of fatty or processed foods. This is the subject of ongoing investigation.

Physical inactivity and incidence of obesity among South Australian adults

The aim of this paper is to examine the association of physical inactivity with incidence of obesity in the South Australian adult population. Two representative data sources were used - the South Australian Monitoring and Surveillance System (SAMSS), a monthly surveillance system, and the North West Adelaide Health Study (NWAHS), a biomedical cohort study. There were 75.3% (n = 12873) SAMSS participants and 72.8% (n = 1521) of NWAHS participants that were not obese at baseline. The cumulative incidence of obesity for SAMSS participants from the previous year to the current year was 2.7%. The cumulative incidence of obesity for NWAHS participants between baseline and stage 3 was 14.4%. Physical inactivity was associated with incident obesity (RR 1.48, 95% CI 1.14-1.90 [SAMSS] and RR 1.41, 95% CI 1.03-1.93 [NWAHS]). This association remained, but was attenuated after adjustment for chronic conditions, risk factors and socio-demographic factors. However, physical activity should be continued to be encouraged in the population for its known additional health benefits.

Asthma in the elderly: what we know and what we have yet to know

In the past, asthma was considered mainly as a childhood disease. However, asthma is an important cause of morbidity and mortality in the elderly nowadays. In addition, the burden of asthma is more significant in the elderly than in their younger counterparts, particularly with regard to mortality, hospitalization, medical costs or health-related quality of life. Nevertheless, asthma in the elderly is still been underdiagnosed and undertreated. Therefore, it is an imperative task to recognize our current challenges and to set future directions. This project aims to review the current literature and identify unmet needs in the fields of research and practice for asthma in the elderly. This will enable us to find new research directions, propose new therapeutic strategies, and ultimately improve outcomes for elderly people with asthma. There are data to suggest that asthma in older adults is phenotypically different from young patients, with potential impact on the diagnosis, assessment and management in this population. The diagnosis of AIE in older populations relies on the same clinical findings and diagnostic tests used in younger populations, but the interpretation of the clinical data is more difficult. The challenge today is to encourage new research in AIE but to use the existing knowledge we have to make the diagnosis of AIE, educate the patient, develop a therapeutic approach to control the disease, and ultimately provide a better quality of life to our elderly patients.

Diagnosis and management of asthma in the elderly

Bronchial asthma is one of the most common chronic diseases worldwide, and by definition not expected to recover with aging. However, the concept that asthma can affect older individuals has been largely denied in the past. In clinical practice, asthma that occurs in the most advanced ages is often diagnosed as COPD, thus leading to undertreatment or improper treatment. The heterogeneity of clinical and functional presentation of geriatric asthma, including the partial loss of reversibility and of the allergic component, contributes to this misconception. A large body of evidence has accumulated demonstrating that the prevalence of asthma in the most advanced ages is similar to that in younger ages. The frequent coexistence of comorbid conditions in older patients compared to younger asthmatics, together with age-associated changes of the human lung, may render the management of asthma a complicated task. The article addresses the main issues related to the diagnosis and treatment of asthma in the geriatric age.

Chronic respiratory conditions in a cohort of metropolitan fire-fighters: associations with occupational exposure and quality of life

OBJECTIVES

To assess the prevalence of chronic respiratory conditions in metropolitan fire-fighters and to study associations between occupational exposure, use of respiratory protection and health-related quality of life (HRQoL) in fire-fighters with and without chronic respiratory conditions.

METHODS

Cross-sectional cohort analysis: Respiratory symptoms, medical conditions, occupational tasks and exposures and consistency of using respiratory protection were inquired by questionnaire. The SF12(®)V2 Health Survey was used to measure physical (PCS-12) and mental (MCS-12) HRQoL. Fire-fighters were categorised in subgroups: asthma; COPD/emphysema/chronic bronchitis; no chronic respiratory conditions; and as being 'not involved' or 'involved' in fire-fighting tasks, the latter further categorised as 'consistent' or 'inconsistent' use of respiratory protection. PCS-12 and MCS-12 scores were compared between subgroups and categories using linear regression.

RESULTS

Five hundred and seventy fire-fighters were analysed, 24 (4%) fulfilled the criteria for asthma, 39 (7%) for COPD/emphysema/chronic bronchitis. Fire-fighters with asthma were older than those in the other two subgroups and had been employed in the fire service longer. Respiratory subgroups did not differ in their involvement in fire-fighting tasks. Ninety-one percent of fire-fighters reported relevant occupational exposure in the past year. Mean PCS-12 scores for fire-fighters with no chronic respiratory conditions, asthma and COPD/emphysema/bronchitis were 52.0 (SD 6.9), 47.0 (8.5) and 48.1 (9.4). For PCS-12 (but not for MCS-12), interaction between having a chronic respiratory condition and inconsistent use of respiratory protection during fire knockdown was observed (p < 0.001).

CONCLUSIONS

Ten percent of metropolitan fire-fighters reported underlying chronic respiratory conditions. Presence of such a condition in combination with suboptimal protection from inhaled exposures may lead to poorer physical HRQoL.

X-linked inhibitor of apoptosis single nucleotide polymorphisms and copy number variation are not risk factors for asthma

BACKGROUND AND OBJECTIVE

Aberrant apoptosis in asthma contributes to airway inflammation. Early apoptosis and fragility of airway epithelial cells and delayed apoptosis of inflammatory lymphocytes can cooperate to increase airway inflammation. In this study, single nucleotide polymorphisms (SNPs) and copy number variation (CNV) in the Baculoviral inhibitor of apoptosis protein repeat-containing 4 (BIRC4) gene (which encodes X-linked inhibitor of apoptosis protein) were evaluated for associations with asthma.

METHODS

Asthma cases (n = 203) were identified from Caucasian cohort participants in the North West Adelaide Health Study and matched with 198 controls. Asthma status was defined using self-report of doctor-diagnosed asthma, in conjunction with spirometry and bronchodilator response. Seven SNPs, which spanned the entire BIRC4 gene, were selected for the study on the basis of a haplotype tagging approach. SNPs genotyping was performed on the SEQUENOM MassARRAY iPLEX Gold platform, and genotyping success rate was > 98%. BIRC4 gene CNV was measured using a duplex Taqman qPCR assay, with RNAseP as the reference gene. Alleles and haplotype associations were analysed by logistic regression, assuming an additive genetic model, and adjusted for gender and atopy.

RESULTS

BIRC4 gene copy number was determined entirely by gender. All SNPs were in Hardy-Weinberg equilibrium for both case and control females. BIRC4 allele and haplotype frequencies were comparable between asthma cases and controls.

CONCLUSIONS

There is no evidence of CNV in BIRC4, and BIRC4 is not a susceptibility gene for asthma.

Sex differences in the relationship between asthma and overweight in Dutch children: a survey study

Objective

Obesity has been identified as a risk factor for asthma in children. However, in the Netherlands, the obesity prevalence is rising while the asthma prevalence in children is stabilising. The aim of this study is to clarify the association between asthma and Body Mass Index (BMI) in children and whether this association is influenced by sex.

Study Design

Parents of 39,316 children (6-16 years) in the south of the Netherlands were invited to complete an online questionnaire on respiratory symptoms, anthropometric variables and several potential confounding factors for asthma and obesity (including sex, birth weight and breastfeeding). Data was analysed by multivariable logistic regression models and an ordinal regression model.

Results

The response rate was 24% (n boys= 4,743, n girls= 4,529). The prevalence of asthma, overweight and obesity was 8%, 15% and 2% respectively. Body mass index - standard deviation Score (BMI-SDS) was related to current asthma (adjusted OR: 1.29; 95%CI: 1.14-1.45, p≤0.001). When stratified for sex, asthma and BMI-SDS were only related in girls (Girls: adjusted OR: 1.31; 95%CI: 1.13-1.51, p≤0.001. Boys: adjusted OR: 1.01; 95%CI: 0.91-1.14, p=0.72).

Conclusions

The positive association between BMI-SDS and asthma is only present in girls, not boys. Future studies into obesity and asthma should correct for sex in their analyses.

Immunolocalization of NLRP3 Inflammasome in Normal Murine Airway Epithelium and Changes following Induction of Ovalbumin-Induced Airway Inflammation

Little is known about innate immunity and components of inflammasomes in airway epithelium. This study evaluated immunohistological evidence for NLRP3 inflammasomes in normal and inflamed murine (Balb/c) airway epithelium in a model of ovalbumin (OVA) induced allergic airway inflammation. The airway epithelium of control mice exhibited strong cytoplasmic staining for total caspase-1, ASC, and NLRP3, whereas the OVA mice exhibited strong staining for active caspase-1, with redistribution of caspase-1, IL-1β and IL-18, indicating possible activation of the NLRP3 inflammasome. Active caspase-1, NLRP3, and other inflammasome components were also detected in tissue eosinophils from OVA mice, and may potentially contribute to IL-1β and IL-18 production. In whole lung, inRNA expression of NAIP and procaspase-1 was increased in OVA mice, whereas NLRP3, IL-1β and IL-18 decreased. Some OVA-treated mice also had significantly elevated and tightly correlated serum levels of IL-1β and TNFα. In cultured normal human bronchial epithelial cells, LPS priming resulted in a significant increase in NLRP3 and II-lp protein expression. This study is the first to demonstrate NLRP3 inflammasome components in normal airway epithelium and changes with inflammation. We propose activation and/or luminal release of the inflammasome is a feature of allergic airway inflammation which may contribute to disease pathogenesis.

Should atopy be assessed in elderly patients with respiratory symptoms suggestive of asthma?

Aging is associated with modifications of the immune system and this could contribute to a reduced prevalence of allergic disease in the elderly. Atopy has rarely been considered in the clinical assessment of the geriatric respiratory patient. This article is a review of the available literature assessing the impact of age on atopy in the asthmatic patient. In the majority of papers, we found a lower prevalence of atopy in the most advanced ages, both in healthy subjects and in individuals affected by allergic respiratory diseases. No large, longitudinal studies performed in the general population have been conducted to confirm this observation. Although available data seem to favor the decline of allergen sensitization with age, the prevalence of allergic sensitizations in the elderly population with respiratory symptoms is substantial enough to warrant evaluation of the atopic condition. For this reason, the evaluation of the atopic condition in the geriatric patient is recommended. The role of atopy as regards diagnosis, therapy and prognosis of asthma in the elderly is addressed.

Comparing self-reported and measured high blood pressure and high cholesterol status using data from a large representative cohort study

OBJECTIVE

To examine the relationship between self-reported and clinical measurements for high blood pressure (HBP) and high cholesterol (HC) in a random population sample.

METHOD

A representative population sample of adults aged 18 years and over living in the north-west region of Adelaide (n=1537) were recruited to the biomedical cohort study in 2002/03. In the initial cross-sectional component of the study, self-reported HBP status and HC status were collected over the telephone. Clinical measures of blood pressure were obtained and fasting blood taken to determine cholesterol levels. In addition, data from a continuous chronic disease and risk factor surveillance system were used to assess the consistency of self-reported measures over time.

RESULT

Self-report of current HBP and HC showed >98% specificity for both, but sensitivity was low for HC (27.8%) and moderate for HBP (49.0%). Agreement between current self-report and clinical measures was moderate (kappa 0.55) for HBP and low (kappa 0.30) for HC. Demographic differences were found with younger people more likely to have lower sensitivity rates. Self-reported estimates for the surveillance system had not varied significantly over time.

CONCLUSION

Although self-reported measures are consistent over time there are major differences between the self-reported measures and the actual clinical measurements. Technical aspects associated with clinic measurements could explain some of the difference.

IMPLICATIONS

Monitoring of these broad population measures requires knowledge of the differences and limitations in population settings.

Asthma in the elderly

Asthma is frequent among older people. Nevertheless, under-recognition, misdiagnosis and under-treatment are still relevant issues. We aim to provide an overview of epidemiology of asthma in the elderly, and a thorough description of its pathology and clinical presentation, with special emphasis on the distinction of late versus early-onset asthma. We also discuss selected treatment topics of special interest for older patients, such as compliance with therapy and ability with the inhalers, which are basic to the success of the prescribed therapy. Finally, we suggest that multidimensional geriatric assessment of older asthmatics could help in tailoring the therapy to the individual needs and capacity.

Association of overweight with asthma prevalence in adolescents in Rio de Janeiro, Brazil

OBJECTIVE

To evaluate the relationship between asthma and overweight in adolescents.

METHODS

Cross-sectional study including 13-14-year-old adolescents in Rio de Janeiro, Brazil. Asthma was defined according to the International Study of Asthma and Allergies in Childhood (ISAAC). Body Mass Index (BMI) was calculated; overweight was defined as BMI > or = 85th percentile. The distribution of asthma and associated symptoms were compared according weight category using the chi(2) test for linear trend. The association between asthma and overweight, controlling for confounding variables, was studied using odds ratios (OR), confidence intervals (95% CI) and logistic regression, stratified by sex.

RESULTS

2,858 (50.1% female) adolescents were studied; 458 (16.1%) were overweight and 13.3% asthmatic. Average BMI was higher among asthmatics (p = 0.01). When stratified, this difference remained only among girls (p = 0.03). Asthma prevalence increased with higher BMI (p = 0.02). Asthma was associated to overweight (OR = 1.51; 95% CI: 1.07-2.13), irrespective of sedentary lifestyle, smoking mother and presence of dog in the domicile, but only among the girls.

CONCLUSIONS

In Rio de Janeiro adolescents, we found a positive association between asthma and overweight, exclusively among girls. This suggests that health policies related to asthma and overweight/obesity in this age group need to take sex into consideration.

Associations of physical and mental health problems with chronic cough in a representative population cohort

BACKGROUND

Although chronic cough is a common problem in clinical practice, data on the prevalence and characteristics of cough in the general population are scarce. Our aim was to determine the prevalence of chronic cough that is not associated with diagnosed respiratory conditions and examine the impact on health status and psychological health, in a representative adult population cohort

METHODS

North West Adelaide Health Study (n stage 1 = 4060, stage 2 = 3160) is a representative population adult cohort. Clinical assessment included spirometry, anthropometry and skin tests. Questionnaires assessed demographics, lifestyle risk factors, quality of life, mental health and respiratory symptoms, doctor diagnosed conditions and medication use.

RESULTS

Of the 3355 people without identified lung disease at baseline, 18.2% reported chronic cough. In multiple logistic regression models, at follow-up, dry chronic cough without sputum production was significantly more common in males (OR 1.5, 95% CI 1.1, 1.9), current smokers (OR 4.9, 95% CI 3.4, 7.2), obesity (OR 1.9, 95% CI 1.3, 2.9), use of ACE inhibitors (OR 1.8, 95% CI 1.1, 2.9), severe mental health disturbance (OR 2.1, 95% CI 1.4, 3.1) and older age (40-59 years OR 1.7 95% CI 1.2, 2.4; > or = 60 years OR 2.1 95% CI 1.3, 3.5). Among non-smokers only, all cough was significantly more common in men, those with severe mental health disturbance and obesity.

CONCLUSIONS

Chronic cough is a major cause of morbidity. Attention to cough is indicated in patients with obesity, psychological symptoms or smokers. Inquiring about cough in those with mental health problems may identify reversible morbidity.

Gender differences in asthma prevalence: variations with socioeconomic disadvantage

BACKGROUND AND OBJECTIVE

Socioeconomic inequalities in health have been shown to vary for different diseases and by gender. This study aimed to examine gender differences in associations between asthma and socioeconomic disadvantage.

METHODS

Socioeconomic variables were assessed among men and women in the North West Adelaide Health Study, a representative population cohort (n = 4060) aged 18 years and over in metropolitan South Australia. Asthma was determined from spirometry and self-reported doctor diagnosis.

RESULTS

The prevalence of asthma was 12.0% (95% CI: 11.1-13.1), and was significantly higher among women (13.5%) than men (10.5%). For participants aged 18-64 years a higher prevalence of asthma was associated with an education level of secondary school or lower, or not being in the paid labour force among men, and with a gross annual household income of $20,000 or less among women. Among socioeconomically advantaged groups, the prevalence of asthma was significantly higher among women than men.

CONCLUSIONS

Socioeconomic disadvantage was associated with higher asthma prevalence, although this varied by gender depending on the indicator of socioeconomic position used. Men with low education or those not employed in the paid labour force had higher asthma prevalence than more socioeconomically advantaged men. Women with low income had higher asthma prevalence than those with higher income. Among all socioeconomically advantaged groups, and also the low-income group, women experienced a higher prevalence of asthma than men.

[Asthma among senior adults]

Elderly patients with asthma are a specific group with particular needs. These must be addressed in order to provide appropriate asthma care. Asthma causes higher morbidity and mortality rates among the elderly patients. Older patients often fail or have problems with compliance and self-management due to age-specific factors. Older patients with asthma are often misdiagnosed, due to an impaired patient perception of symptom severity, different opinions of what kind of asthma-control is possible, or not sufficient communication skills. Often the quality of life is impaired by asthma. Improvement in self management skills in a special way may enhance the health status of elderly patients with asthma.

Body mass index and asthma incidence in the Black Women's Health Study

BACKGROUND

Evidence from prospective studies consistently links obesity to asthma onset in white women, although there is controversy as to whether the association is causal. There are few data on this topic in black women, among whom the prevalence of obesity and asthma is high.

OBJECTIVE

We prospectively assessed the relation of body mass index (BMI) to asthma incidence in the Black Women's Health Study.

METHODS

We followed 46,435 women from 1995 through 2005 with biennial mailed questionnaires. Cox regression models were used to estimate incidence rate ratios and 95% CIs.

RESULTS

During 403,394 person-years of follow-up, 1068 participants reported physician-diagnosed asthma and concurrent use of asthma medication. Compared with women with BMIs of 20 to 24, the multivariate incidence rate ratios for higher categories of BMI increased from 1.26 (95% CI, 1.05-1.51) for BMIs of 25 to 29 to 2.85 (95% CI, 2.19-3.72) for BMIs of 40 or greater, with a significant trend. The association of BMI with asthma risk was consistent across strata of smoking status, age, presence of sleep apnea, parental history of asthma, BMI at age 18 years, and energy expenditure and intake.

CONCLUSION

In this large cohort of African American women, there was a positive association between BMI and asthma risk that was similar in magnitude to those observed in longitudinal studies of white women.

Coexistent chronic conditions and asthma quality of life: a population-based study

OBJECTIVE

Reports of the prevalence and impact of comorbid conditions among people with asthma have been limited to certain population groups or convenience samples. Our aim was to examine the prevalence of major comorbidity in asthma and associations with quality of life and functional status in the general population.

STUDY DESIGN/SETTING

The WANTS Health and Well-being Survey is a cross-sectional representative population household telephone interview survey in three Australian states.

PARTICIPANTS

Representative sample of noninstitutionalized adults in three Australian states.

MEASUREMENT AND RESULTS

From the available sample of 10,080 patients, 7,619 interviews were completed (participation rate, 74.8%), with 834 people reporting current doctor-diagnosed asthma (11.2%). People with asthma were more likely to report one of the selected comorbid conditions: diabetes, arthritis, heart disease, stroke, cancer, osteoporosis (adjusted odds ratio, 1.9; 95% confidence interval, 1.5 to 2.2). Among people with asthma, there were statistically and clinically significant decreases in usual activity levels and in Short Form-12 physical component summary scores when another chronic condition was also present. For those with any of the chronic conditions, the additional presence of asthma was associated with significant further impairment in quality of life in those aged > 35 years but not in younger adults.

CONCLUSION

The significant reduction in quality of life associated with comorbidity in asthma has implications for disease management and organization of care, as well as for the design and external validity of single-disease clinical trials.

Asthma and older people in general practice

WHAT WE NEED TO KNOW: Why is there undiagnosed and untreated asthma in older people in the community and in general practice? What patient, general practitioner and organisational factors contribute to this? Are current best practice guidelines appropriate for older people with asthma? WHAT WE NEED TO DO: Undertake broad community and general practice screening to identify characteristics of older people with undiagnosed asthma. Analyse GPs' perspectives and decision-making processes for older people with dyspnoea. Undertake targeted research in general practice, trialling decision-making frameworks for older patients with dyspnoea. Undertake appropriate and relevant community and GP awareness campaigns about the prevalence of asthma in older people. Analyse current best practice management of asthma, including self-management and the Asthma 3+ Visit Plan, in older people.

An algorithmic approach to diagnosing asthma in older patients in general practice

WHAT WE NEED TO KNOW: How effective would an algorithm be in helping general practitioners diagnose asthma? What proportion of older people with undiagnosed asthma fail to recognise symptoms? What proportion of the population believe asthma does not occur in the older population? What systems or supports do GPs need to diagnose asthma more effectively? WHAT WE NEED TO DO: Work on developing a gold standard for asthma diagnosis. Develop prototype algorithms for general practice discussion. Conduct a general practice study to assess the effectiveness of an algorithm. In conjunction with GPs, develop a pilot program to increase awareness of the current asthma problem. Conduct focus-group research to identify why some people do not believe they can develop asthma for the first time in adult life. Conduct focus-group research to identify why some adults do not attribute asthma symptoms to asthma. Conduct focus groups with GPs to identify what support is needed to diagnose asthma more effectively. Consult with all stakeholders before an intervention is used. Evaluate any interventions used.

Spirometric criteria for asthma: adding further evidence to the debate

BACKGROUND

Objective assessments of pulmonary function are considered essential for the diagnosis of asthma. The degree of reversibility of FEV(1) considered supportive of asthma varies between international asthma guidelines.

OBJECTIVE

We sought to compare the relative performance of international guideline reversibility criteria for identifying impairment in persons with a significant bronchodilator response (SBR) without an asthma diagnosis.

METHODS

The North West Adelaide Health (Cohort) Study, a population biomedical study of 4060 subjects, conducted spirometry according to American Thoracic Society criteria. SBR was defined as postbronchodilator FEV(1) responses of at least 12% or 15% of baseline values, 9% of predicted values, or 400 mL. A self-completed questionnaire assessed current asthma (CA), respiratory symptoms, and participant demographics.

RESULTS

The prevalence of CA was 9.4% (n = 380), whereas 1.3% (>/=400 mL) to 4.5% (>/=9% of predicted value) of participants demonstrated an SBR in the absence of CA. With the exception of the 9% predicted criterion, prebronchodilator mean FEV(1) (percent predicted) in those demonstrating an SBR but no CA was significantly worse than that in the CA group. Significantly more respiratory symptoms were experienced by the SBR groups than the group without asthma. Logistic regression analyses identified different characteristics of those classified by the following criteria: 12% and 15%, age of 40 years or greater and household income of less than $40,000; 9% predicted, household income of less than $40,000; 400 mL, male sex (odds ratio, 4.5; 95% CI, 2.1-9.3).

CONCLUSIONS

Different criteria identify different persons, but SBR by any criteria was associated with significant respiratory impairment, some of which might be attributable to asthma. Postbronchodilator change as a percentage of predicted value was the least biased of the criteria.

Impact of asthma on self-reported health status and quality of life: a population based study of Australians aged 18-64

BACKGROUND

The impact of asthma has traditionally been measured in terms of the prevalence of the disease, mortality rates, and levels of healthcare utilisation, particularly hospital admissions. However, the impact of asthma extends beyond these outcomes to include effects on lifestyle, well being, and perceived health status.

METHODS

Information on self-reported current asthma status, arthritis and diabetes as well as measures of life satisfaction, self-assessed health status, psychological distress, and interference with usual activities was obtained for 14 641 respondents aged 18-64 years in the 2001 National Health Survey of the general population in all states and territories in Australia. Log linear models were fitted separately for each of the dichotomised quality of life measures as dependent variables. The estimates of the adjusted rate ratio obtained from each model were used to compute the population attributable fraction (PAF) of self-reported asthma, arthritis, and diabetes for each of the health status and quality of life measures.

RESULTS

The presence of asthma accounted for 3.18% (95% CI 2.13 to 4.23) of people reporting poor life satisfaction, 8.12% (95% CI 6.57 to 9.67) of people reporting poor health status, 5.90% (95% CI 4.19 to 7.61) of people reporting high psychological distress, and 3.58% (95% CI 2.16 to 5.01) of people reporting any reduced activity days. The proportions of people with these adverse health states attributable to asthma were higher than the proportions attributable to diabetes but lower than the proportions attributable to arthritis.

CONCLUSION

Asthma is an important contributor to the burden of ill health and impaired quality of life in the community. A strategic approach is needed to develop and implement strategies to address the impact of asthma on quality of life.

Achieving asthma control

The number of people with asthma continues to grow around the world. However, despite the availability of highly effective medication it remains a poorly controlled disease. Reasons for this poor control include non-implementation and inherent limitations of the asthma management guidelines, poor compliance with asthma therapy, incorrect use of inhaler devices and insufficient treatment of peripheral airway inflammation. Guidelines may not be efficiently implemented as they may be complicated and difficult to understand. In addition, the scientific evidence upon which they are based, although the best available at the present time, is flawed. Patient non-compliance with therapy is a major reason for poor asthma control. Patients fail to comply with their asthma regimen for a wide variety of reasons, but incorrect use of inhaler devices is amongst the most common. Most patients derive incomplete benefit from pressurised metered dose inhalers (pMDIs) as they are unable to use them correctly. Dry powder inhalers (DPIs) have several advantages over pMDIs; they are breath-activated (avoiding coordination difficulties between actuation and inhalation), easy and convenient to use, and environmentally friendly. Although there are many treatments for asthma currently in development, it is unlikely that significant improvements in inhaled medication will occur within the next 15 years. Therefore, improvement in asthma management will be facilitated by improvements in inhaler technology. When choosing an inhaler device it is essential that it is easy to use correctly, dosing is consistent, adequate drug is deposited in the lungs (both central and peripheral airways) and that drug deposition is independent of airflow.

Characterisation of atopic and non-atopic wheeze in 10 year old children

BACKGROUND

Wheezing occurs in both atopic and non-atopic children. The characteristics of atopic and non-atopic wheeze in children at 10 years of age were assessed and attempts made to identify whether different mechanisms underlie these states.

METHODS

Children were seen at birth and at 1, 2, 4 and 10 years of age in a whole population birth cohort study (n = 1456; 1373 seen at 10 years). Information was collected prospectively on inherited and early life environmental risk factors for wheezing. Skin prick testing, spirometry, and methacholine bronchial challenge were conducted at 10 years. Wheezing at 10 years of age was considered atopic or non-atopic depending on the results of the skin prick test. Independent significant risk factors for atopic and non-atopic wheeze were determined by logistic regression.

RESULTS

Atopic (10.9%) and non-atopic (9.7%) wheeze were equally common at 10 years of age. Greater bronchial hyperresponsiveness (p<0.001) and airways obstruction (p = 0.011) occurred in children with atopic wheeze than in those with non-atopic wheeze at 10 years. Children with atopic wheeze more often received treatment (p<0.001) or an asthma diagnosis for their disorder, although current morbidity at 10 years differed little for these states. Maternal asthma and recurrent chest infections at 2 years were independently significant factors for developing non-atopic wheeze. For atopic wheeze, sibling asthma, eczema at 1 year, rhinitis at 4 years, and male sex were independently significant.

CONCLUSIONS

Non-atopic wheeze is as common as atopic wheeze in children aged 10 years, but treatment is more frequent in those with atopic wheeze. Different risk factor profiles appear relevant to the presence of atopic and non-atopic wheeze at 10 years of age.

Asthma prevention: breast is best?

Whilst breastfeeding has been considered to exert a preventative effect on the development of allergic disease, several recent publications have challenged this view, particularly with respect to the long-term outcomes for asthma. There are many other beneficial effects of breastfeeding apart from the possibility of allergy prevention. The suggestion that breastfeeding may increase the development of allergic disease raises concerns about the appropriate steps to take for primary prevention of allergy. It is concluded that breastfeeding can still be recommended for the beneficial effects in reducing atopic disease in childhood in addition to the other demonstrated benefits, and that there are unresolved questions concerning the few studies that suggest the possibility of increased allergic disease in later life.