Background: Inhaled corticosteroids (ICSs) are recommended as the first line of treatment in children with moderate-to-severe asthma. Exhaled nitric oxide (ENO) has been proposed as a clinically useful marker of control that might help identify patients in whom ICS dose may be safely reduced. Objective: To evaluate the ability of ENO to predict future asthma exacerbations in children with moderate-to-severe asthma undergoing ICS tapering. Methods: This is an observational study with no control group. ENO was measured biweekly for 14 weeks in 32 children with moderate-to-severe asthma who were undergoing ICS tapering. Clinical evaluations and spirometry were performed concomitantly, and families kept daily diaries to record symptoms between visits. We used generalized estimating equations to model the In (odds) of an asthma exacerbation in the subsequent 2-week interval as a function of ENO level at the start of the interval while adjusting for age, sex, asthma severity, and current medication use. Results: We were able to successfully lower ICS doses in 10 (56%) of the 18 children with moderate asthma and in 3 (21%) of the 14 children with severe asthma. In 83 of the 187 follow-up clinical evaluations, children were determined to have had an exacerbation during the preceding 2 weeks. ENO levels...

INTRODUÇÃO: O conhecimento da prevalência das doenças alérgicas é de fundamental importância para a instituição de medidas para sua prevenção. Vários métodos têm sido utilizados para este fim, sendo que recentemente o questionário padronizado ISAAC (International Study of Asthma and Allergies in Childhood) tem permitido a comparação dos dados epidemiológicos em várias regiões. Os OBJETIVOS deste estudo foram: avaliar a prevalência da asma, rinite e eczema atópicos e sintomas relacionados, entre escolares de 6 a 7 anos, da região oeste da cidade de São Paulo, utilizando-se o questionário escrito ISAAC e comparar os dados encontrados com aqueles obtidos na fase I do Estudo ISAAC em São Paulo, examinando tendências temporais na prevalência das doenças alérgicas. MÉTODOS: Entre junho e outubro de 2002 foi aplicado questionário escrito ISAAC em 3.312 alunos. As diferenças entre proporções foram avaliadas pelo Teste do Qui-quadrado e quando necessário o Teste Exato de Fisher, sendo também calculados a Razão das Chances (Odds Ratio OR) e intervalo de confiança 95% (IC 95%) entre os sexos e na associação das doenças alérgicas. Os valores de p < 0,05 foram considerados de significância estatística. Após obtenção dos resultados...

OBJECTIVE: The best combination of questions to define asthma in epidemiological asthma studies is not known. We summarized the operational definitions of asthma used in prevalence studies and empirically assess how asthma prevalence estimates vary depending on the definition used. METHODS: We searched the Thomson Reuters ISI Web of knowledge and included (1) cross-sectional studies (2) on asthma prevalence (3) conducted in the general population and (4) containing an explicit definition of asthma. The search was limited to the 100 most-cited papers or published since January 2010. For each paper, we recorded the asthma definition used and other variables. Then we applied the definitions to the data of the Portuguese National Asthma survey (INAsma) and of the 2005-2006 National Health and Nutrition Examination Survey (NHANES) computing asthma prevalence estimates for the different definitions. RESULTS: Of 1738 papers retrieved, 117 were included for analysis. Lifetime asthma, diagnosed asthma and current asthma were defined in 8, 12 and 29 different ways, respectively. By applying definitions of current asthma on INAsma and NHANES data, the prevalence ranged between 5.3%-24.4% and 1.1%-17.2%, respectively. CONCLUSIONS: There is considerable heterogeneity in the definitions of asthma used in epidemiological studies leading to highly variable estimates of asthma prevalence. Studies to inform a standardized operational definition are needed. Meanwhile...

OBJECTIVE: In individuals with asthma, obesity induces the production of leptin and is associated with disease severity. Our objective was to evaluate the levels of serum leptin and their effect on Th1/Th2 balance in obese and non-obese children with asthma, as well as to investigate the association between serum leptin levels and clinical outcomes. METHODS: We evaluated 50 atopic children with physician-diagnosed moderate-to-severe persistent asthma and 20 controls. The children with asthma were divided into two groups, by body mass index percentile: obese (n = 25) and non-obese (n = 25). From all subjects, we collected peripheral blood samples in order to determine the levels of leptin, IFN-γ, and IL-4. Asthma severity was assessed by an asthma symptom score, and the results were correlated with the parameters studied. RESULTS: Serum leptin levels were significantly higher in the obese asthma group than in the non-obese asthma group, as well as being significantly higher in the children with asthma than in the controls, whereas IFN-γ levels were significantly higher and IL-4 levels were significantly lower in the obese asthma group than in the non-obese asthma group. In addition, the obese asthma group showed higher asthma symptom scores and significantly lower FEV1 (% of predicted) than did the non-obese asthma group. There was a significant positive correlation between leptin and IFN-γ levels only in the obese asthma group. CONCLUSIONS: Although leptin is involved in the pathogenesis of asthma in obese and non-obese children...

Background: The relative contributions of genetics and environment to asthma in Hispanics or to asthma in children younger than 3 years are not well understood. Objective: To examine the relative contributions of genetics and environment to early-childhood asthma by performing a longitudinal twin study of asthma in Puerto Rican children ≤3 years old. Methods: 678 twin infants from the Puerto Rico Neo-Natal Twin Registry were assessed for asthma at age 1 year, with follow-up data obtained for 624 twins at age 3 years. Zygosity was determined by DNA microsatellite profiling. Structural equation modeling was performed for three phenotypes at ages 1 and 3 years: physician-diagnosed asthma, asthma medication use in the past year, and ≥1 hospitalization for asthma in the past year. Models were additionally adjusted for early-life environmental tobacco smoke exposure, sex, and age. Results: The prevalences of physician-diagnosed asthma, asthma medication use, and hospitalization for asthma were 11.6%, 10.8%, 4.9% at age 1 year, and 34.1%, 40.1%, and 8.5% at 3 years, respectively. Shared environmental effects contributed to the majority of variance in susceptibility to physician-diagnosed asthma and asthma medication use in the first year of life (84%–86%)...

L’asthme est connu comme l’une des maladies chroniques les plus fréquentes chez la femme enceinte avec une prévalence de 4 à 8%. La prévalence élevée de l’asthme fait en sorte qu’on se préoccupe de l’impact de la grossesse sur l’asthme et de l’impact de l’asthme sur les issus de la grossesse. La littérature présente des résultats conflictuels concernant l’impact de l’asthme maternel sur les issus périnatales comme les naissances prématurées, les bébés de petit poids et les bébés de petit poids pour l’âge gestationnel (PPGA). De plus, les données scientifiques sont rares concernant l’impact de la sévérité et de la maîtrise de l’asthme durant la grossesse sur les issus périnatales. Donc, nous avons mené cinq études pour réaliser les objectifs suivants: 1. Le développement et la validation de deux indexes pour mesurer la sévérité et la maîtrise de l’asthme. 2. L’évaluation de l’impact du sexe du fœtus sur le risque d’exacerbation de l’asthme maternel et l’utilisation de médicaments antiasthmatiques durant la grossesse; 3. L’évaluation de l’impact de l’asthme maternel sur les issus périnatales; 4. L’évaluation de l’impact de la sévérité de l’asthme maternel durant la grossesse sur les issus périnatales; 5. L’évaluation de l’impact de la maîtrise de l’asthme maternel durant la grossesse sur les issus périnatales. Pour réaliser ces projets de recherche...

Background: The prevalence of undiagnosed asthma in the general population and the clinical and demographic characteristics of these patients compared with those with diagnosed asthma are unclear. Methods: The North West Adelaide Health Survey (NWAHS) is a population household interview survey of adults (age >18 years) in the north western suburbs of Adelaide, South Australia (regional population 0.6 million). Data obtained were weighted to the closest census data to provide population representative estimates. Positive answers to: "Have you ever had asthma?"; "Has it been confirmed by a doctor?"; "Do you still have asthma?" determined current physician diagnosed asthma. A positive bronchodilator response on spirometric testing according to ATS criteria without a physician’s diagnosis determined undiagnosed asthma. Other measures included the SF-12 health survey questionnaire, the Selim index of severity of chronic lung disease, skin allergy tests, and demographic data. Results: Of the 3422 individuals interviewed, 2523 (74%) agreed to participate in the clinical assessment. Of these, 292 (11.6%) had asthma, 236 (9.3%) with a doctor’s diagnosis of asthma and 56 (2.3%) with undiagnosed asthma defined on spirometric criteria; thus...

OBJECTIVE: To examine the comparative prevalence and distribution of obesity and psychological disturbance in the asthma and non-asthma populations, and to determine how these comorbidities are associated with physical functioning. DESIGN, SETTING AND PARTICIPANTS: A South Australian population-representative study of 3175 adults who provided data on asthma, psychological morbidity, physical functioning, and body mass index. Bivariate and multivariate analyses identified how these comorbidities were distributed in asthma and non-asthma subpopulations, and the variance in physical functioning that they explained. MAIN OUTCOME MEASURES: Rates of obesity and psychological morbidity, and physical functioning scores in asthma and non-asthma populations. RESULTS: Men and women in the asthma population had similar prevalences of obesity (35.3% v 33.6%) and psychological morbidity (29.5% v 29.4%). When compared with non-asthma controls, both comorbidities were significantly higher only in men with asthma. The prevalence of psychological morbidity within different weight categories in the asthma population compared with non-asthma weight-category controls varied by sex. Physical functioning was lower in the asthma population than the non-asthma population (46.6 [95% CI...

Induced sputum examination (IS), an established research tool to measure airway inflammation (AI), is normally confined to specialised institutions and selected populations with airway disease, especially asthma. This thesis examines the role of IS in the diagnosis of asthma in a community. The first study explores the accepted definitions of asthma, the utility of IS, and another marker of AI, exhaled nitric oxide (eNO), in establishing the diagnosis of asthma. The findings confirm that symptoms, variable airflow obstruction and airway hyper-responsiveness (AHR) are inter-linked in the definition of asthma. Bronchodilator reversibility (BDR), used traditionally, remains the most specific test to aid a diagnosis of asthma in the community. The results favour a tailored approach in the diagnosis of asthma using BDR initially, then selecting a test, either eNO or IS depending on the clinical scenario. The usefulness of AHR with hypertonic saline to diagnose asthma is equivocal given the moderate sensitivity and poor specificity of the test documented within. If a global assessment of AI is required, an eNO measurement is recommended initially, given its ease of use. Sputum examination is useful in delineating the subtype of AI present. Dyspnoea is a cardinal symptom in asthma. Studies have shown a correlation between AI measured by IS and an altered perception of dyspnoea (POD) in selected subjects with asthma. The aim of the second and third studies was to determine if a similar relationship exists in subjects with and without AHR from a community sample. In both groups...

This thesis investigates the complexity in the relationship between obesity and asthma and asthma morbidity. Previous epidemiological studies exploring these relationships have been limited by sample bias and the use of restricted phenotypes of body mass index (BMI) and self-reported asthma, ignoring the problem of undiagnosed asthma, and more pathogenic central obesity phenotypes. Cardiovascular disease (CVD), a systemic manifestation of obesity may be augmented by asthma-related airway inflammation, yet studies inconsistently identifying an association with asthma have failed to assess the role of asthma phenotype or cardiotoxic effects of short acting beta-2 adrenergic agonists (SABA). Understanding the consequences of this complexity is fundamental to the development of appropriate policy and intervention. The North West Adelaide Health Study, a representative biomedical population sample (n=4006) permitted an examination of the role of phenotype in the association of obesity [body mass index (BMI), waist circumference, waist to hip ratio] with asthma [atopy, significant bronchodilator reversibility (SBR)]. Optimising the identification of asthma in the absence of a gold standard test is important. The prevalence of undiagnosed asthma (SBR in absence of doctor diagnosis) was variable (1.6% to 4.5%) depending on the SBR criteria specified. The observed symptom burden and lung function impairments suggest that all criteria identified subjects with probable asthma. SBR criteria were associated with different sociodemographic factors and the 9% of the predicted criterion was least biased particularly in terms of age and sex. Generalised (BMI) and central obesity were associated with asthma in females only. After consideration of atopic status...

Background: Little is known about the psychosocial impact and perceived teratogenic (fetal harm due to medication) risks of asthma treatment (inhaled/oral corticosteroids and β-agonist) during pregnancy. Aims: To assess the perception of asthma control, quality of life (QoL), and perceived risks of therapy in pregnant women with asthma. Methods: Pregnant women with asthma (n = 125) were recruited between 12 and 20 weeks gestation. QoL (generic: Short Form-12 Health Survey v1, and asthma specific: Asthma Quality of Life Questionnaire-Marks (AQLQ-M)) and psychological variables were assessed using the Perceived Control of Asthma Questionnaire (PCAQ), the Brief Illness Perception Questionnaire, and the Six-Item Short-Form State Trait Anxiety Inventory (STAI-6). Women’s perceptions of the teratogenic risks of asthma therapy were also assessed and analyzed for adherence to maintenance inhaled corticosteroids (ICSs), poor asthma control, and QoL. Results: Women reported good QoL (median AQLQ-M total score/maximum score = 0.88/10), moderate ability to deal with asthma symptoms (mean PCAQ score = 42.6/55), positive beliefs about their asthma and low anxiety (median STAI score = 26.7/80). Perceived teratogenic risks for asthma drugs were excessive and class dependent. Women perceived there was a 42% teratogenic risk for oral corticosteroid...

Background: Pregnancy presents a unique situation for the management of asthma as it can alter the course of asthma severity and its treatment, which in turn can affect pregnancy outcomes. Despite awareness of the substantial adverse effects associated with asthma during pregnancy, little has been done to improve its management and reduce associated perinatal morbidity and mortality. The aim of this randomized controlled trial is to evaluate the clinical and cost effectiveness of an Antenatal Asthma Management Service. Methods/design: Design: Multicentre, randomized controlled trial. Inclusion criteria: Women with physician diagnosed asthma, which is not currently in remission, who are less than 20 weeks gestation with a singleton pregnancy and do not have a chronic medical condition. Trial entry and randomization: Eligible women with asthma, stratified by treatment site, disease severity and parity, will be randomized into either the ‘Standard Care Group’ or the ‘Intervention Group’. Study groups: Both groups will be followed prospectively throughout pregnancy. Women in the ‘Standard Care Group’ will receive routine obstetric care reflecting current clinical practice in Australian hospitals. Women in the ‘Intervention Group’ will receive additional care through the nurse-led Antenatal Asthma Management Service...

A asma é uma doença heterogênea caracterizada por um processo inflamatório crônico das vias aéreas inferiores que está associado ao desenvolvimento da hiperresponsividade brônquica e remodelamento da via aérea. Atualmente, a asma é considerada uma síndrome, ou ao menos uma doença com diversos fenótipos. Tradicionalmente, dois fenótipos são bem definidos pela clínica e exames subsidiários: asma alérgica e asma não alérgica. Eles são diferentes quanto á idade de início, apresentação clínica, história pessoal e familiar de atopia e resposta ao tratamento. Ao contrário da asma alérgica, cuja fisiopatologia está bem caracterizada, a etiologia e mecanismos envolvidos na asma não alérgica não estão bem elucidados. Algumas possibilidades incluem alergia desencadeada por antígenos desconhecidos (fungos), infecção persistente (Chlamydia trachomatis, Mycoplasma sp) e auto-imunidade. Estudos têm descrito em diferentes populações associações entre a asma e alelos/antígenos HLA classe I e II, mas os resultados têm sido inconclusivos. O objetivo deste estudo foi identificar possíveis associações do antígeno leucocitário humano (HLA) classe I (A, B, C) e II (DR, DQ, DP) em pacientes brasileiros com asma alérgica e não alérgica. Um total de 109 pacientes com o diagnóstico de asma (56 com asma alérgica e 53 com asma não alérgica) que estavam em acompanhamento no Serviço de Imunologia Clínica e Alergia do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo...

OBJECTIVE: To examine the relationships between ownership of written asthma action plans, asthma morbidity, use of devices, and patients' perceptions of their asthma management. DESIGN AND SETTING: A random population survey (in 1996) of the South Australian population aged 15 years or over, using interviewers to administer a questionnaire. PARTICIPANTS: People who reported that they had current, doctor-diagnosed asthma. MAIN OUTCOME MEASURES: Prevalence of written asthma action plans; night-time awakenings from asthma; ownership of peak flow meters; and people's perceptions of their asthma management. RESULTS: The ownership of asthma action plans by people with self-reported asthma was 33% and has declined since 1995 (42%; P < 0.001). Fifteen per cent were awakened weekly or more frequently by asthma symptoms. These people were more likely to have a peak flow meter and a written action plan, but less likely to consider they had been provided with enough information about their asthma, to feel comfortable managing their asthma, or to find it easy to see their doctor. Having a written asthma action plan was associated with regular corticosteroid use, understanding asthma, having enough information and owning a peak flow meter. CONCLUSIONS: Ownership of asthma action plans in South Australia is suboptimal. Before we develop new strategies to improve asthma outcomes...

OBJECTIVES: To identify factors associated with asthma patients' perceptions of the propensity of pulmonologists to involve them in treatment decision-making, and its association with asthma outcomes. DESIGN: Cross-sectional observational study performed from June 1995 to December 1997. SETTING: Pulmonary unit of a university teaching hospital. PATIENTS: Adult patients with asthma (n = 128). MEASUREMENTS AND RESULTS: By patient self-report, mean physician's participatory decision-making (PDM) style score was 72 (maximum 100, 95% CI 65, 79). PDM scores were significantly correlated (P < .0001) with the duration of clinic visits (r = .63), patient satisfaction (r = .53), duration of tenure of doctor-patient relationship (r = .37), and formal education (r = .22, P = .023). Significantly higher PDM style scores were reported when visits lasted longer than 20 minutes and when a patient had a >6-month relationship with a particular doctor. PDM scores were also significantly correlated with possession of a written asthma action plan (r = .54, P < .0001), days affected by asthma (r = .36, P = .0001), asthma symptoms (r = .23, P = .017), and preferences for autonomy in asthma management decisions (r = .28, P = .0035). Those with PDM scores <50 reported significantly lower quality of life for all domains of a disease-specific instrument and the Short-Form 36 health survey version 1.0. In multiple regression analysis...

BACKGROUND: Studies examining the influence of provider behavior and patterns of care delivery on the use of anti-inflammatory asthma therapy have been limited to selected populations or have been unable to assess the appropriateness of therapy for individuals. We have previously reported the influence of sociodemographic variables and asthma severity on reported use of asthma medications in the United States. Objective: We sought to examine the influence of patterns of care delivery and clinician behavioral factors on the use of anti-inflammatory medication by patients with asthma. METHODS: We performed a cross-sectional national random digit dial household telephone survey in 1998 of adult patients and parents of children with current asthma. Respondents were classified as having current asthma if they had a physician's diagnosis of asthma and were either taking medication for asthma or had asthma symptoms during the past year. Results: One or more persons met the study criteria for current asthma in 3273 (7.8%) households in which a screening questionnaire was completed. Of the 2509 persons (721 children <16 years of age) with current asthma interviewed, 507 (20.1%) reported current use of anti-inflammatory medication. In a multiple logistic regression model controlling for asthma symptoms...

BACKGROUND: Studies of the use of anti-inflammatory asthma therapy have been limited to selected populations or have been unable to assess the appropriateness of therapy for individuals. OBJECTIVE: We sought to describe the current use of asthma medication in the United States population and to examine the influence of symptoms and sociodemographics on medication use. Methods: This study was based on a cross-sectional, national, random-digit-dial household telephone survey in 1998 designed to identify adult patients and parents of children with current asthma. Respondents were classified as having current asthma if they had a physician's diagnosis of asthma and were either taking medication for asthma or had asthma symptoms during the past year. RESULTS: One or more persons met the study criteria for current asthma in 3273 (7.8%) households in which a screening questionnaire was completed. Of these, 2509 persons (721 children <16 years) with current asthma were interviewed. Current use of anti-inflammatory medication was reported by 507 (20.1%). Of these, most were using inhaled corticosteroids (72.5%), with use of antileukotrienes reported by 11.4% and use of cromolyn-nedocromil reported by 18.6%. Of persons with persistent asthma symptoms in the past month...

This study identifies several factors that appear to influence children's sense of competence to manage their asthma. The study examined a consecutive series of 62 children and adolescents who had been admitted to hospital for management of their asthma. Self-reports rating their sense of competence to manage their asthma were obtained from all the children. In addition, reports were obtained of the children's motivation to achieve healthy functioning, their sense of control over their health, and parental knowledge of childhood asthma management. Results from the study suggest that older children, children who are more intrinsically motivated to achieve healthy functioning, and children with parents who are knowledgable about asthma management feel more competent to manage their asthma. It is suggested that the effectiveness of asthma self-management programs for children may be improved if there is a better understanding of the psychological factors that influence children's sense of competence to manage their asthma.; Angela Miles, Michael Sawyer, and Declan Kennedy

Background: School settings are one of the most crucial context for asthma management second only to a child’s home. Today school administrators are faced with many challenges, not only are they responsible for students' learning needs but they also manage complex behavioural and health issues including asthma. Most do not have standardized plans regarding asthma management. Objectives: 1) Systematically review the research literature related to asthma management within the school setting. 2) Determine current asthma management practices as reported by school administrators. 3) Explore experiences and barriers to asthma management practices with school administrators. Method: Guided by the Knowledge to Action framework, the study was divided in three phases using a planned action approach and included an integrative synthesis of the evidence, an administrators’ survey, and an administrator’s meeting. Findings: Phase One: Following a search using three databases, 67 articles were critiqued. The literature illustrates that many countries have established “asthma friendly schools” legislation that includes process for identifying children with asthma, right to self-carry and administer medications, enhancing communication and cooperation between school staff...

INTRODUÇÃO: O aumento da prevalência das doenças alérgicas tem sido associado a vários fatores de risco e a detecção destes e a avaliação da prevalência em diferentes regiões é fundamental. O protocolo padronizado ISAAC (International Study of Asthma and Allergies in Childhood), possibilitou a comparação destes dados epidemiológicos. Os OBJETIVOS deste estudo foram: avaliar a prevalência da asma, rinite e eczema alérgicos e sintomas relacionados, entre escolares de 13 a 14 anos, da região oeste da cidade de São Paulo, utilizando-se o questionário escrito ISAAC e identificar possíveis fatores de risco associados à presença de asma ou à positividade ao teste cutâneo de hipersensibilidade imediata (TCHI). MÉTODOS: Entre fevereiro de 2002 e outubro de 2003 foi aplicado questionário escrito ISAAC em 3181 alunos. Após amostragem sistemática, 528 alunos foram submetidos ao TCHI para o diagnóstico de atopia e responderam a um questionário complementar sobre antecedentes familiares e condições ambientais. Foram constituídos grupos de alunos com ou sem asma, considerando-se a presença de sintomas de asma nos últimos 12 meses, e com ou sem TCHI positivo a pelo menos um aeroalérgeno. A análise dos fatores de risco foi realizada pelo teste do qui-quadrado ou teste exato de Fisher e por regressão binária logística (Backward Stepwise). RESULTADOS: As prevalências encontradas foram: asma de 21...