Clinical Diagnosis Of Asthma Research Articles

Mannitol Bronchoprovocation in the Evaluation of Airway Reactivity in a High-Risk Pediatric Cohort

The aim of this study was to examine the properties of a new indirect bronchoprovocation test using inhaled mannitol (AridolTM) for evaluating airway hyperreactivity and its relationship with various phenotypic characteristics in children. Children at high risk for development of asthma and allergic disease based on parental histories were enrolled at birth into the Childhood Origins of Asthma (COAST) study and followed prospectively. At age 11 years, 171 children underwent a mannitol challenge. A positive challenge was defined as the provocative dose that caused a 15% fall in FEV1 (PD15). Relationships among mannitol challenge with clinical asthma diagnosis at age 11, allergen sensitization (as determined by specific IgE), and total IgE were evaluated. Total and specific IgE were measured by fluoroenzyme immunoassay (UniCap 100, Pharmacia Diagnostics). Of the 170 children who began the mannitol challenge, 146 children (86%) completed the procedure successfully. 57 of 144 children in the cohort were diagnosed with asthma at age 11. Of the children with asthma, 40% had a positive challenge; while 79% of non-asthmatics had a negative challenge (p = 0.01). The procedure demonstrated a specificity of 79% with a sensitivity of 40%. Although allergen sensitization was not associated with mannitol hyperresponsiveness, total IgE levels were inversely associated with the PD15 (r = -0.19, p = 0.03). In children, mannitol challenge has low sensitivity but relatively high specificity for current asthma. In addition, total IgE levels, but not the presence of allergic sensitization, were inversely associated with the PD15.

A systematic review of the effectiveness of patient-centred care on emergency room visits, hospitalizations, unscheduled sick clinic visits, and missed school days for children with asthma

Review Questions/Objectives The overall objective is to conduct a systematic review to extract, appraise, and synthesize the best available evidence to determine the effectiveness of patient-centred care in the management of children with asthma. Review Question: In children with asthma, what is the effect of patient-centred care versus traditional care on emergency room visits, hospitalizations, unscheduled primary care provider visits, and missed school days? Inclusion Criteria Types of Participants The review will consider studies that include children from newborn to seventeen years of age with a clinical diagnosis of asthma who are being treated in an outpatient healthcare setting, regardless of severity, previous treatments, co-morbidities, and ethnic or socioeconomic backgrounds. Types of interventions The review will consider studies that evaluate the effects of the patient-centred care model in the management of children with asthma. Comparator Traditional care as previously mentioned. Types of Outcome Measures This review will consider studies that include the following outcome measures: emergency room visit rates, hospital admission rates, unscheduled visit to primary care provider rates, and number of missed school days per year associated with asthma symptoms.

Asthma diagnosis and treatment: Filling in the information gaps

Current approaches to the diagnosis and management of asthma are based on guideline recommendations, which have provided a framework for the efforts. Asthma, however, is emerging as a heterogeneous disease, and these features need to be considered in both the diagnosis and management of this disease in individual patients. These diverse or phenotypic features add complexity to the diagnosis of asthma, as well as attempts to achieve control with treatment. Although the diagnosis of asthma is often based on clinical information, it is important to pursue objective criteria as well, including an evaluation for reversibility of airflow obstruction and bronchial hyperresponsiveness, an area with new diagnostic approaches. Furthermore, there exist a number of treatment gaps (ie, exacerbations, step-down care, use of antibiotics, and severe disease) in which new direction is needed to improve care. Amajor morbidity in asthmatic patients occurs with exacerbations and in patients with severe disease. Novel approaches to treatment for these conditions will be an important advance to reduce the morbidity associated with asthma.

Patterns of airway disease and the clinical diagnosis of asthma in the Busselton population

The aim of this study was to examine how objective measures related to lung function cluster in the general population and how the patterns relate to asthma and bronchitis as diagnosed by a doctor (DDA and DDB, respectively). A cross-sectional survey of an age-stratified random general population sample of 1,969 adults from the electoral register of Busselton (Australia) was performed in 2005-2007. Respiratory symptoms, DDA ever, DDB ever, recent wheezing and smoking history, together with anthropometric measurements, forced expiratory volume in 1 s (FEV₁) and forced vital capacity (FVC), methacholine challenge or bronchodilator response, exhaled nitric oxide (eNO), skin-prick tests to common allergens, and blood eosinophil and neutrophil counts were studied. Cluster analysis (variables sex, age, atopy, FEV₁ % predicted, FEV₁/FVC, airway hyperresponsiveness, eNO, log eosinphil count, log neutrophil count and body mass index) was used to identify phenotypic patterns. Seven clusters (subjects with DDA and DDB, respectively) were identified: normal males (n=467; 7 and 13%), normal females (n=477; 12 and 18%), obese females (n=250; 16 and 28%), atopic younger adults (n=330; 21 and 17%), atopic adults with high eNO (n=130; 30 and 25%), atopic males with reduced FEV₁ (n=103; 33 and 32%) and atopic adults with bronchial hyperreactivity (n=212; 40 and 26%). The clinical diagnosis of asthma (ever) and bronchitis (ever) is not specific for any of the clustering patterns of airway abnormality.

A systematic review of the effectiveness of patient-centred care on emergency room visits, hospitalizations, unscheduled sick clinic visits, and missed school days for children with asthma.

Review Questions/Objectives The overall objective is to conduct a systematic review to extract, appraise, and synthesize the best available evidence to determine the effectiveness of patient-centred care in the management of children with asthma. Review Question: In children with asthma, what is the effect of patient-centred care versus traditional care on emergency room visits, hospitalizations, unscheduled primary care provider visits, and missed school days? Inclusion Criteria Types of Participants The review will consider studies that include children from newborn to seventeen years of age with a clinical diagnosis of asthma who are being treated in an outpatient healthcare setting, regardless of severity, previous treatments, co-morbidities, and ethnic or socioeconomic backgrounds. Types of interventions The review will consider studies that evaluate the effects of the patient-centred care model in the management of children with asthma. Comparator Traditional care as previously mentioned. Types of Outcome Measures This review will consider studies that include the following outcome measures: emergency room visit rates, hospital admission rates, unscheduled visit to primary care provider rates, and number of missed school days per year associated with asthma symptoms.

The Inflammatory Basis of Exercise-Induced Bronchoconstriction

Exercise-induced bronchoconstriction (EIB) is common in individuals with asthma, and may be observed even in the absence of a clinical diagnosis of asthma. Exercise-induced bronchoconstriction can be diagnosed via standardized exercise protocols, and anti-inflammatory therapy with inhaled corticosteroids (ICS) is often warranted. Exercise-related symptoms are commonly reported in primary care; however, access to standardized exercise protocols to assess EIB are often restricted because of the need for specialized equipment, as well as time constraints. Symptoms and lung function remain the most accessible indicators of EIB, yet these are poor predictors of its presence and severity. Evidence suggests that exercise causes the airways to narrow as a result of the osmotic and thermal consequences of respiratory water loss. The increase in airway osmolarity leads to the release of bronchoconstricting mediators (eg, histamine, prostaglandins, leukotrienes) from inflammatory cells (eg, mast cells and eosinophils). The objective assessment of EIB suggests the presence of airway inflammation, which is sensitive to ICS in association with a responsive airway smooth muscle. Surrogate tests for EIB, such as eucapnic voluntary hyperpnea or the osmotic challenge tests, cause airway narrowing via a similar mechanism, and a response indicates likely benefit from ICS therapy. The complete inhibition of EIB with ICS therapy in individuals with asthma may be a useful marker of control of airway pathology. Furthermore, inhibition of EIB provides additional, useful information regarding the identification of clinical control based on symptoms and lung function. This article explores the inflammatory basis of EIB in asthma as well as the effect of ICS on the pathophysiology of EIB.

Early wheezing phenotypes and cognitive development of 3-yr-olds. Community-recruited birth cohort study.

The main purpose of the study was to answer the question whether young children without clinical diagnosis of asthma but experiencing early wheezing disorders and therefore being at high risk of developing asthma may have cognitive deficits. In the ongoing birth cohort study wheezing symptoms were recorded postpartum over two first years of age and subsequently cognitive status of children at the age of 3 yr was assessed with the Bayley Mental Development Index (MDI). In the statistical analysis a wide range of modifying and confounding factors (maternal education, gender of children, prenatal exposure to lead and environmental tobacco smoke (ETS) were considered to assess the independent effect of early wheezing phenotypes on cognitive development of children. The MDI score correlated inversely with the number of wheezing days recorded over 24 months (r = -0.13, p = 0.007), lead cord blood concentration (r = -0.12, p = -0.02), number of siblings (r = -0.17, p = 0.0006) and the number of cigarettes smoked daily by other household members at home over the pregnancy period (r = -0.18, p = 0.0002). While the children who experienced wheezing over the first year of age showed deficit of 2 MDI scores (beta coeff. = -2.31, 95%CI: -4.63 to 0.02), those with persistent wheezing had the score deficit of 4 points (beta coeff. = -4.41, 95%CI: -8.27 to -0.55). To our knowledge, it is the first report in the iterature showing that early wheezing is associated the cognitive deficit in a community-recruited very young children. Observed cognitive deficit in early wheezers may be caused by RSV infections or can be related to lower lung function attributed to persistent wheezing, which reducing oxygen supply would affect rapidly developing brain.

The effects of meteorological factors and Alternaria spore concentrations on children sensitised to Alternaria

Alternaria is the most important fungal species belonging to the class Deuteromycetes which causes allergic respiratory diseases. The fungus pattern often shows a pronounced seasonal periodicity and with fluctuations related to meteorological conditions. In this study, we aimed to investigate the effect of outdoor Alternaria spore concentrations on monthly lung function tests, symptoms, and medication scores in children sensitised only to Alternaria. Additionally, we planned to determine the Alternaria spores of the outdoor environment in Adana, with special respect to their relationships with meteorological conditions and their seasonal changes. Twenty-five patients with a clinical diagnosis of asthma and/or rhinitis sensitised only to Alternaria were enrolled in the prospective study. Meteorological data and outdoor samples of airborne fungi were obtained between November 2006 and October 2007. The outdoor Alternaria spore concentrations were significantly correlated with the monthly average temperature (r=0.626, p=0.03) and monthly average barometric pressure (r=-0.613, p=0.03). Similarly, the outdoor Alternaria spore concentrations were significantly correlated with mean monthly asthma medication score (r=0.599, p=0.04), value monthly PEF (r=-0.737, p=0.006), value monthly FEF25-75% (r=-0.914, p=0.0001) and, variation in PEF (r=0.901, p=0.0001). The atmospheric concentration of Alternaria spores are markedly affected by meteorological factors such as air temperatures and barometric pressures. In hypersensitive patients, Alternaria spores can induce decreases in respiratory functions and development of allergic symptoms between May and September, being especially more influential in August.

Current guidelines for the management of asthma in young children

The diagnosis and management of asthma in young children is difficult, since there are many different wheezy phenotypes with varying underlying aetiologies and outcomes. This review discusses the different approaches to managing young children with wheezy illnesses presented in recently published global guidelines. Four major guidelines published since 2007 are considered. Helpful approaches are presented to assist the clinician to decide whether a clinical diagnosis of asthma can, or should be made in a young child with a recurrent wheezy illness and which treatments would be appropriate, dependent on risk factors, age of presentation, response to initial treatment and safety considerations. Each of the guidelines provide useful information for clinicians assessing young children with recurrent wheezy illnesses. There are differences in classification of the disease and treatment protocols. Although a firm diagnosis of asthma may only be made retrospectively in some cases and there are several effective guidelines to initiating treatment. Consistent review of the need for ongoing treatment with a particular pharmacological modality is essential, since many children with recurrent wheezing in infancy go into spontaneous remission. It is probable that newer biomarkers of airway inflammation will assist the clinician as to when to initiate and when to continue pharmacological treatment in the future.

Do School-Based Asthma Education Programs Improve Self-Management and Health Outcomes?

Asthma self-management education is critical for high-quality asthma care for children. A number of studies have assessed the effectiveness of providing asthma education in schools to augment education provided by primary care providers. To conduct a systematic review of the literature on school-based asthma education programs. As our data sources, we used 3 databases that index peer-reviewed literature: MEDLINE, the Cochrane Central Register of Controlled Trials, and the Cumulative Index to Nursing and Allied Health Literature. Inclusion criteria included publication in English and enrollment of children aged 4 to 17 years with a clinical diagnosis of asthma or symptoms consistent with asthma. Twenty-five articles met the inclusion criteria. Synthesizing findings across studies was difficult because the characteristics of interventions and target populations varied widely, as did the outcomes assessed. In addition, some studies had major methodologic weaknesses. Most studies that compared asthma education to usual care found that school-based asthma education improved knowledge of asthma (7 of 10 studies), self-efficacy (6 of 8 studies), and self-management behaviors (7 of 8 studies). Fewer studies reported favorable effects on quality of life (4 of 8 studies), days of symptoms (5 of 11 studies), nights with symptoms (2 of 4 studies), and school absences (5 of 17 studies). Although findings regarding effects of school-based asthma education programs on quality of life, school absences, and days and nights with symptoms were not consistent, our analyses suggest that school-based asthma education improves knowledge of asthma, self-efficacy, and self-management behaviors.

The potential use of spirometry during methacholine challenge test in young children with respiratory symptoms

The concentration of methacholine that causes a fall of 20% from baseline forced expiratory volume in the first second (PC20-FEV1) in the methacholine challenge test (MCT) is not usually considered a diagnostic tool in preschool children since PC20-FEV1 may not be achievable <6 years of age. To assess the usefulness of various spirometry indices obtained during MCT in a large group of 3- to 6-year-old children with respect to their clinical diagnosis. Standardized MCT (inhaled triple-concentration increments [0.057-13.925 mg] of methacholine solution) was performed by 84 children previously diagnosed with asthma (asthmatics) and 48 with prolonged cough (coughers). Spirometry was determined at baseline and between inhalations; PC20-FEV1 and PC25-FEV0.5 were calculated. PC20-FEV1 values were significantly less in the asthmatics than in the coughers (mean +/- SD was 3.21 +/- 4.32 vs. 22.35 +/- 3.66 ml/mg). Similarly, PC25-FEV0.5 was 1.48 +/- 3.08 in the asthmatics and 9.45 +/- 12.59 mg/ml/Mch in the coughers, P < 0.0001. A cut-off at 4.0 mg/ml for PC20-FEV1 had 77.4% sensitivity and 75.0% specificity, a cut-off at 2.2 mg/ml for PC25-FEV0.5 had 73.8% sensitivity and 72.9% specificity, for clinical diagnosis of asthma. PC25-FEV0.5 also showed a correlation with age. Our findings suggest that MCT can be performed in preschool children with various respiratory symptoms. PC25-FEV0.5 may be a better end-point parameter. Children with a clinical diagnosis of asthma respond to a lower MCT concentration than children with cough. Further studies are needed to determine airway responsiveness in healthy young children and to further assess the contribution of MCT to the clinical diagnosis in this age group.

Association between Renin-Angiotensin System Gene Polymorphism and Recurrent Wheezing in Chinese Children: A 4-year Follow-up Study

This study aimed to clarify the association between angiotensin-converting enzyme (ACE) gene polymorphisms and infant wheezing, and to determine whether an association may contribute to early prediction of persistent wheezing and asthma. The study cohort comprised 149 patients with asthma, 169 patients with wheezing but no clinical diagnosis of asthma and 165 healthy control subjects. The insertion/deletion (I/D) polymorphism of the ACE gene was determined by polymerase chain reaction. Total serum immunoglobulin E was determined for the wheezy group and a 4-year follow-up study was carried out to observe wheezing relapse. Significant differences were found between patients and controls in allele frequency and genotype distribution. The DD genotype was more frequent in patients in the wheezing and asthma groups than in the control subjects. Patients with the DD genotype had a higher frequency of relapse than patients expressing the ID or II genotypes. It is concluded that the DD genotype of ACE is a risk factor for recurrent wheezing in early childhood.

Office spirometry can improve the diagnosis of obstructive airway disease in primary care setting

Spirometry may reveal pre-clinical abnormal airway function in asymptomatic subjects and allow a better definition of severity in clinically diagnosed asthma and COPD. The hypothesis of this study was that telespirometry might increase the diagnostic accuracy of asthma and COPD. In the Italian "Alliance" study, 638 general practitioners (GPs) were trained to perform telespirometry and were asked to enroll the following categories of subjects: (a) current or ex-smokers without respiratory symptoms; (b) subjects with respiratory symptoms but without a pre-existing diagnosis of asthma or COPD; (c) subjects with a pre-existing clinical diagnosis of asthma; and (d) subjects with a pre-existing clinical diagnosis of COPD. Subjects completed a case report form (CRF) and performed telespirometry in the GP's office. Traces were sent by telephone to a Telespirometry Central Office, where they were interpreted by a pulmonary specialist, according to appropriately defined criteria. The results were returned in real time to the GP. Overall, 9312 subjects were recruited and 7262 (78%) performed an acceptable telespirometric examination and the CRF. In the asymptomatic group, 340/1437 (24%) of the telespirometries were abnormal (147 with moderate-to-severe airway obstruction, i.e. FEV(1) <80% of predicted). Among symptomatic subjects, 1433/3725 (38%) had abnormal telespirometries (682 with moderate-to-severe obstruction). Of the asthmatic subjects, 336/1285 (26%) had moderate-to-severe airway obstruction, while telespirometry was normal in 184/815 (23%) of the COPD group. Telespirometry, performed in a GP's office, can aid the diagnosis of obstructive airway diseases and could help GPs to better manage airway obstruction.

Effects of Asthma Education on Children's Use of Acute Care Services: A Meta-analysis

National Heart, Lung, and Blood Institute clinical practice guidelines strongly recommend that health professionals educate children with asthma and their caregivers about self-management. We conducted a meta-analysis to estimate the effects of pediatric asthma education on hospitalizations, emergency department visits, and urgent physician visits for asthma. Inclusion criteria included enrollment of children aged 2 to 17 years with a clinical diagnosis of asthma who resided in the United States. Pooled standardized mean differences and pooled odds ratios were calculated. Random-effects models were estimated for all outcomes assessed. Of the 208 studies identified and screened, 37 met the inclusion criteria. Twenty-seven compared educational interventions to usual care, and 10 compared different interventions. Among studies that compared asthma education to usual care, education was associated with statistically significant decreases in mean hospitalizations and mean emergency department visits and a trend toward lower odds of an emergency department visit. Education did not affect the odds of hospitalization or the mean number of urgent physician visits. Findings from studies that compared different types of asthma education interventions suggest that providing more sessions and more opportunities for interactive learning may produce better outcomes. Providing pediatric asthma education reduces mean number of hospitalizations and emergency department visits and the odds of an emergency department visit for asthma, but not the odds of hospitalization or mean number of urgent physician visits. Health plans should invest in pediatric asthma education or provide health professionals with incentives to furnish such education. Additional research is needed to determine the most important components of interventions and compare the cost-effectiveness of different interventions.

Montelukast Improves Regional Air-Trapping Due to Small Airways Obstruction in Asthma

Zeidler MR, Kleerup EC, Goldin JG, et al. Eur Respir J. 2006;27:307–315 PURPOSE OF THE STUDY. To assess the effects of montelukast on regional air-trapping, airway hyperresponsiveness, and small-airway physiology using quantitative image analysis with high-resolution computed tomography (HRCT). STUDY POPULATION. Sixteen patients (7 women, 9 men) aged 18 to 65 with no use of inhaled corticosteroids for the past 2 months, a forced expiratory volume in 1 second (FEV1) of &amp;gt;60% predicted, a provocation dose that causes a 20% decrease in FEV1, and a clinical diagnosis of asthma. METHODS. The study was designed as a randomized, double-blind, placebo-controlled crossover trial. Subjects received either montelukast 10 mg or a placebo given once daily in the evening for 4 weeks. The subjects then crossed over to the alternate treatment for 4 more weeks. Regional air-trapping was assessed by HRCT at residual volume before and after methacholine challenge and was performed at baseline and after each of the drug phases was complete. Other indices of hyperresponsiveness and physiology were measured as well. RESULTS. Significantly less regional air-trapping was seen on the premethacholine images of patients treated with montelukast. However, no effect on increases in regional air-trapping was seen on the postmethacholine images in these same patients. There were no differences seen in global indices of small-airways physiology between montelukast and placebo. Montelukast resulted in improved quality-of-life scores. CONCLUSIONS. Montelukast improved small-airways disease in asthmatic subjects, but this improvement can only be detected by HRCT, not by physiologic studies. REVIEWER COMMENTS. Although montelukast improved distal airway function, it is noted that at baseline, the patients in the montelukast group showed a greater degree of air-trapping, and this difference cannot be excluded as having an effect on the findings. One question that this study raised is why montelukast's beneficial effects are only measurable with HRCT and not by physiologic means. The authors alluded to the poor sensitivity of physiologic indices and their large degree of intrasubject test variability. They also refer to the inhomogeneous pattern of small-airway involvement and the greater reliability of computer-derived quantitative image analysis versus qualitative radiographic techniques. Sample size was also limited in this study, which involved only mildly asthmatic subjects, indicating that further and expanded studies need to be performed. Montelukast's inability to reduce hyperresponsiveness to methacholine should also be investigated further.

Accuracy of Arabic Versions of Three Asthma Symptoms Questionnaires Against the Clinical Diagnosis of Asthma

Validation studies of asthma symptom questionnaires against provocation tests of bronchial hyperresponsiveness have shown comparable performances of written and video taped questionnaires. This study aimed to determine the test characteristics of Arabic versions of two written and one video taped questionnaires when compared to the clinical diagnosis of asthma made by two respiratory physicians. The written International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire had higher sensitivities and greater accuracy than the other two questionnaires. Comparisons between corresponding questions and scenes in the ISAAC questionnaires in general revealed no significant differences in performance. The ISAAC written questionnaire had test characteristics consistent with its potential use as a screening instrument for asthma in this population of children.

Asthma is associated with acute chest syndrome and pain in children with sickle cell anemia

AbstractPain and acute chest syndrome (ACS) episodes are 2 of the most common causes of hospitalization in children with sickle cell anemia (SCA). However, very few potentially modifiable risk factors for either condition have been identified. In this prospective infant cohort study, we tested the hypothesis that asthma is associated with an increased incidence rate of pain and ACS episodes. An infant cohort was composed of 291 African American children with hemoglobin SS enrolled in the Cooperative Study for Sickle Cell Disease before age 6 months and followed beyond age 5 years. Asthma was defined by a physician diagnosis, an acute asthma event, or use of prescription asthma medications. The incidence rates of ACS and painful episodes were compared for children with and without asthma. A clinical diagnosis of asthma was made in 17% of the cohort. Asthma was associated with more frequent ACS episodes (0.39 vs 0.20 events per patient year, P < .001) and painful episodes (1.39 vs 0.47 events per patient year, P < .001). In conclusion, in children with SCA, asthma is associated with an increased incidence of sickle cell disease–related morbidity, including ACS and painful episodes.

Controversies in the management of preschool viral wheeze

The clinical diagnosis of asthma represents several putative wheeze phenotypes, each associated with a unique cluster of risk factors, underlying inflammation, and response to therapy. In school-age children, the 'classical' atopic asthma phenotype predominates. By contrast, asthma in children aged between 1 and 5 years is frequently characterised by transient episodes of wheeze trigged by viral colds, with few or no interval symptoms (preschool viral wheeze). This phenotype has a different cluster of risk factors from atopic asthma and thus might not respond to asthma therapies of proven efficacy in older children. The objective of this review is to look at the current evidence in the management of 'preschool viral wheeze'.

Comparison of the Efficacy and Safety of Live Attenuated Cold-Adapted Influenza Vaccine, Trivalent, With Trivalent Inactivated Influenza Virus Vaccine in Children and Adolescents With Asthma

Despite their potential for increased morbidity, 75% to 90% of asthmatic children do not receive influenza vaccination. Live attenuated influenza vaccine (LAIV), a cold-adapted, temperature-sensitive, trivalent influenza vaccine, is approved for prevention of influenza in healthy children 5 to 19 years of age. LAIV has been studied in only a small number of children with asthma. Children 6 to 17 years of age, with a clinical diagnosis of asthma, received a single dose of either intranasal CAIV-T (an investigational refrigerator-stable formulation of LAIV; n = 1114) or injectable trivalent inactivated influenza vaccine (TIV; n = 1115) in this randomized, open-label study during the 2002-2003 influenza season. Participants were followed up for culture-confirmed influenza illness, respiratory outcome, and safety. The incidence of community-acquired culture-confirmed influenza illness was 4.1% (CAIV-T) versus 6.2% (TIV), demonstrating a significantly greater relative efficacy of CAIV-T versus TIV of 34.7% (90% confidence interval [CI] 9.4%-53.2%; 95% CI = 3.9%-56.0%). There were no significant differences between treatment groups in the incidence of asthma exacerbations, mean peak expiratory flow rate findings, asthma symptom scores, or nighttime awakening scores. The incidence of runny nose/nasal congestion was higher for CAIV-T (66.2%) than TIV (52.5%) recipients. Approximately 70% of TIV recipients reported injection site reactions. CAIV-T was well tolerated in children and adolescents with asthma. There was no evidence of a significant increase in adverse pulmonary outcomes for CAIV-T compared with TIV. CAIV-T had a significantly greater relative efficacy of 35% compared with TIV in this high-risk population.

A qualitative analysis of a dyad approach to health-related quality of life measurement in children with asthma

The measurement of health-related quality of life (HRQOL) in children often relies on parents as proxy respondents. Yet, several studies have shown poor to moderate correlations between parent and child responses, questioning the validity of the parent as proxy. This qualitative study examined a dyad approach, where parent and child were interviewed together. The objective was to observe and describe the interaction in a dyad interview, wherein both parent and child perspectives are used and where the parent may expand the child's cognitive abilities to create a more meaningful description of the child's HRQOL. Children aged 8–15 years with a clinical diagnosis of asthma and their primary caregivers were recruited from The Hospital for Sick Children, Toronto, Canada. The dyads were administered the Health Utilities Index Mark II/III, the Pediatric Asthma Quality of Life Questionnaire and the PedsQL™ Pediatric Quality of Life Inventory. Interviews were audio-taped and a second researcher recorded observations. Consistent with Grounded Theory methodology, observations were indexed according to categories and subcategories related to the response process. Data were analysed using open, axial and selective coding and constant comparison. Saturation was achieved at 16 dyad interviews. A cultural review and reflexive role taking were included to minimize interviewer bias and enhance rigour. Findings were grouped in the following 11 themes: recall difficulty, respondent bias, interviewer bias, frustration, coercion/parental influence, inter-relational conflict, psychic discomfort for health states, emotional sensitivity, parent as advocate, parent as enabler and comprehension. The specification of these categories facilitated the creation of an interview guide to accompany the administration of standardized HRQOL questionnaires to parent–child dyads. Such a guide would facilitate discussion between parent and child and enhance the consistency of the interview process.