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PubMed2006

The Breathmobile: a novel comprehensive school-based mobile asthma care clinic for urban underprivileged children.

Urban minority children have higher rates of asthma morbidity due to multiple factors. Many school-based programs have been funded to improve asthma management, especially for these "high-risk" inner-city children with asthma. Here we report the outcomes of the Children's Hospital of Orange County Breathmobile program, which is a school-based asthma program that combines the use of a mobile clinic and a pediatric asthma specialist. Baseline evaluations included a detailed history and physical, skin prick test to common allergens, spirometry measurements, and asthma severity classification based on the current National Asthma Education and Prevention Program guidelines. From April 2002 to September 2005, a total of 1321 children were evaluated for asthma. Analysis of the 1112 (84%) children diagnosed with asthma showed a population mean age of 7.8 years, 81% Latino ethnicity, and 73% with persistent disease. At baseline, only 24% of children with persistent asthma were on daily anti-inflammatory medications, which increased to 78% by the first follow-up visit. In the year prior to entry into the program, 64% had school absenteeism related to asthma (38% >10 days), 45% had emergency room (ER) visits (28% >1), and 19% had hospitalizations (9% >1). There was a significant reduction (p < .001) in the annual rates of ER visits, hospitalizations, and school absenteeism when comparing pre- and postentry into the program. These data suggest that a mobile asthma van clinic at the school site with an asthma specialist could be an effective model in reducing morbidity in the underserved child with asthma. Further studies are necessary to determine whether this model is applicable to other inner-city settings.

Absenteeism↗
PubMed2000

Frequent paracetamol use and asthma in adults.

BACKGROUND: The pulmonary antioxidant glutathione may limit airway inflammation in asthma. Since paracetamol (acetaminophen) depletes the lung of glutathione in animals, a study was undertaken to investigate whether frequent use in humans was associated with asthma. METHODS: Information was collected on the use of analgesics as part of a population based case-control study of dietary antioxidants and asthma in adults aged 16-49 years registered with 40 general practices in Greenwich, South London. The frequency of use of paracetamol and aspirin was compared in 664 individuals with asthma and in 910 without asthma. Asthma was defined by positive responses to questions about asthma attacks, asthma medication, or waking at night with shortness of breath. The association between analgesic use and severity of disease amongst asthma cases, as measured by a quality of life score, was also examined. RESULTS: Paracetamol use was positively associated with asthma. After controlling for potential confounding factors the odds ratio for asthma, compared with never users, was 1.06 (95% CI 0.77 to 1.45) in infrequent users (<monthly), 1.22 (0.87 to 1.72) in monthly users, 1. 79 (1.21 to 2.65) in weekly users, and 2.38 (1.22 to 4.64) in daily users (p (trend) = 0.0002). This association was present in users and non-users of aspirin and was stronger when cases with more severe disease were compared with controls; amongst cases increasing paracetamol use was associated with more severe disease. Frequency of aspirin use was not associated with asthma when cases as a whole were compared with controls, nor with severity of asthma amongst cases. Frequent paracetamol use was positively associated with rhinitis, but aspirin use was not. CONCLUSIONS: Frequent use of paracetamol may contribute to asthma morbidity and rhinitis in adults.

Acetaminophen↗
PubMed1998

Case-control study of salmeterol and near-fatal attacks of asthma.

BACKGROUND: A case-control study was undertaken to investigate the hypothesis that the use of the long acting beta agonist salmeterol increases the risk of a near-fatal attack of asthma. METHODS: The cases comprised admissions to the intensive care unit (ICU) for asthma in 14 major hospitals within the Wessex region in 1992. For each of the cases four age-matched controls were selected from asthma admissions to the same hospital during the same period. Information on prescribed drug therapy for the 48 cases and 185 controls was collected from the hospital admission records. RESULTS: The patients admitted to the ICU had greater chronic asthma severity and had generally been prescribed more asthma drugs than the control admissions to hospital. The relative risk of a near-fatal attack of asthma in patients prescribed inhaled salmeterol was 2.32 (95% CI 1.05 to 5.16), p = 0.04. However, the salmeterol relative risk decreased to 1.42 (95% CI 0.49 to 4.10), p = 0.52 when the analysis was restricted to the more chronically severe patients (those in the subgroup of patients with a hospital admission for asthma in the previous 12 months). These findings suggest that the increased unadjusted relative risk with salmeterol is predominantly due to confounding by severity--that is, the increased relative risk is due to patients with more severe asthma (at greatest risk of a near-fatal asthma attack) being preferentially prescribed salmeterol. This interpretation is supported by the finding in this study that, within the control group (selected from the population of asthmatics requiring hospital admission), salmeterol was preferentially prescribed to the most severe patients (a threefold greater prescription of salmeterol to control patients if they had been admitted to hospital in the 12 months prior to the index admission). There was no increased risk of a near-fatal attack of asthma in patients prescribed a beta agonist by metered dose inhaler (OR 0.75 (95% CI 0.31 to 1.78), p = 0.51). In contrast, the relative risks for beta agonists delivered by nebulisation (OR 3.86 (95% CI 1.99 to 7.50), p < 0.001) and oral theophylline (OR 2.45 (95% CI 1.26 to 4.78), p < 0.01) were increased and did not markedly decrease when the analysis was restricted to the more severe asthmatic subjects. CONCLUSIONS: Although these findings are not conclusive, particularly because of the small numbers involved in some subgroup analyses, they suggest that the use of salmeterol by patients with chronic severe asthma is not associated with a significantly increased risk of a near-fatal attack of asthma. If a near-fatal asthma attack is considered to be an intermediate step in a process by which a severe attack of asthma may become fatal, these results would suggest that salmeterol is unlikely to be associated with an increased risk of death, at least by this mechanism.

Adolescent↗
PubMed1999

Dietary antioxidants and magnesium in type 1 brittle asthma: a case control study.

BACKGROUND: Type 1 brittle asthma is a rare form of asthma. Atopy, psychosocial factors and diet may contribute to this condition. As increased dietary magnesium has a beneficial effect on lung function and selenium, vitamins A, C and E have antioxidant properties, a study was undertaken to test the hypothesis that patients with brittle asthma have diets deficient in these nutrients compared with subjects with non-brittle asthma and healthy adults. METHODS: A case control study of the dietary intakes of 20 subjects with brittle asthma, 20 with non-brittle asthma, and 20 healthy adults was performed using five day weighed dietary records. Intake of magnesium was the primary outcome measure with selenium and vitamins A, C and E as secondary outcomes. Serum levels were measured at the same time as the dietary assessment. RESULTS: Sixty subjects (27 men) of mean age 49.5 years were recruited and completed the study. Subjects with brittle asthma had statistically lower median dietary intakes of vitamins A and E than the other groups (vitamin A: brittle asthma 522.5 micrograms/day, non-brittle asthma 869.5 micrograms/day, healthy adults 806.5 micrograms/day; vitamin E: brittle asthma 4.3 mg/day, non-brittle asthma 4.6 mg/day, healthy adults 4.5 mg/day). Median dietary intakes for the other nutrients were not significantly different between groups. Serum levels were within normal ranges for each nutrient in all subjects. Intakes less than the reference nutrient intake (RNI) for magnesium and vitamins A and C, and less than the safe intake (SI) for vitamin E were more likely in patients with brittle asthma than in those with non-brittle asthma. CONCLUSION: Nutrient deficiency and reduced antioxidant activity may contribute to disease activity in type 1 brittle asthma, although a prospective study of replacement therapy will be needed to confirm this hypothesis.

Ascorbic Acid Deficiency↗
PubMed1999

Early use of inhaled nedocromil sodium in children following an acute episode of asthma.

BACKGROUND: Current guidelines on the treatment of childhood asthma recommend the introduction of an anti-inflammatory drug in children who have persistent symptoms and require regular treatment with a bronchodilator. The efficacy and safety of inhaled nedocromil sodium (Tilade Mint aerosol) administered using a Fisonair spacer at a dose of 4 mg three times daily was compared with placebo in the treatment of asthmatic children aged 6-12 years who are symptomatic and recovering from an acute exacerbation of asthma. METHODS: A group comparative, double blind, placebo controlled trial was performed in children who were recovering from an acute episode of asthma following treatment in the emergency department of the hospital or in children referred from their general practitioner following a wheezing episode and documented evidence of at least two previous episodes of wheezing. A two week baseline period on existing bronchodilator treatment was followed by a 12 week treatment period on either nedocromil sodium (2 mg/puff) or placebo. Both treatments were administered using a Fisonair spacer at a dose of two puffs three times daily. Changes from baseline values in daytime asthma and night time asthma symptom scores, usage of rescue bronchodilators, mean peak expiratory flow (PEF) recorded twice daily on diary cards, patients' opinion of treatment, and withdrawals due to treatment failure were measured during the primary treatment period (last six weeks of treatment). RESULTS: One hundred and forty two children aged 6-12 years entered the baseline period. Sixty three were withdrawn due to failure to meet the entry criteria (18) or the criteria for asthma symptom severity (15) or reversibility (9), because they developed uncontrolled asthma (2), because they took disallowed treatment (2), or for other non-trial related reasons (17). Seventy nine patients (46 boys) of mean age 8. 8 years entered the treatment period. There were significant differences in the changes from baseline values during the last six weeks of treatment in favour of nedocromil sodium compared with placebo in the primary variables of daytime asthma and night time asthma, morning and evening PEF, and the usage of rescue inhaled bronchodilators; 53% of patients reported nedocromil sodium to be very or moderately effective compared with 44% placebo. Improvement in asthma symptoms, PEF, and reduction in use of rescue bronchodilators did not reach statistical significance until after six weeks of treatment. Twenty two patients were withdrawn or dropped out during the treatment phase, 12 due to uncontrolled asthma or persistence of asthma symptoms, four due to suspected adverse drug reactions (nedocromil sodium 3 (headaches 2, angio-oedema/urticaria 1), placebo 1(persistent cough)), and six due to non-treatment related reasons. Seventy one adverse events were reported by 27 patients in the nedocromil group and 75 by 30 patients in the placebo group. CONCLUSIONS: Asthma symptoms, use of bronchodilators, and lung function can be improved significantly in children recovering from an acute exacerbation of asthma or wheeze and currently receiving treatment with bronchodilators alone by the addition of inhaled nedocromil sodium at a dose of 4 mg three times daily administered using a Fisonair holding chamber.

Acute Disease↗
PubMedDate not supplied

Control of asthma in Canada: failure to achieve guideline targets.

OBJECTIVE: To assess the degree of asthma control achieved by patients with asthma in Canada and to describe the impact of poor asthma control. DESIGN: Population-based, cross-sectional telephone interview survey of Canadians with doctor-diagnosed asthma. SUBJECTS AND METHODS: Random digit dialing was used to identify a representative sample of Canadians with asthma. A total of 801 adults and 200 parents of children aged four to 15 years were interviewed over the telephone. Telephone interviews were also conducted with 266 physicians. RESULTS: Only 24% of patients achieved disease control by meeting the six symptom-based criteria listed by the 1996 Canadian Asthma Consensus Guidelines as appropriate treatment targets. Fifty-seven per cent of patients failed to meet two or more of the six control criteria and were considered poorly controlled. Fifty-one per cent had required urgent care for out of control asthma at least once in the year before the survey. Nonetheless, 91% of patients thought that their asthma was adequately controlled. Physicians shared this optimism: 77% of family physicians and 90% of respirologists believed that they were usually able to achieve optimal asthma control in their patients. Few physicians gauged asthma control by tracking more than one or two symptoms, and just over one-half (54%) of patients surveyed recalled ever having had a lung function test. One-half (48%) of patients with poorly controlled asthma who used inhaled steroids did not understand the role of inhaled steroids; one-third (32%) of patients with poorly controlled asthma who used short acting bronchodilators misunderstood the action of quick relief bronchodilators. CONCLUSIONS: The majority of Canadians with asthma suffer from inadequate control of their disease. Suboptimal control of asthma is associated with excess health care use. Inadequate monitoring by physicians and poor patient education may be factors contributing to this problem.

Anti-Asthmatic Agents↗
PubMed1997

Perceived control of asthma: development and validation of a questionnaire.

Psychological factors can play a role in asthma symptoms and may play a role in how individuals manage asthma. Because poor self-management of asthma has been linked to poor outcomes, it is important to understand perceived control of asthma--the individual's perceived ability to deal with asthma and its exacerbations effectively. This study used data from an ongoing panel study of adults with asthma (n = 601). The 11-item Perceived Control of Asthma Questionnaire (PCAQ) demonstrated internal consistency (Cronbach's alpha = 0.74) and excellent construct validity, correlating strongly with asthma severity, quality of life, and Medical Outcomes Study Short Form (SF-36) measures of health status (p < 0.05). After controlling for demographics and asthma severity, each 6-point decrement in PCAQ score was significantly associated with increased risk of hospitalization (OR = 1.4 [95% CI: 1.1 to 1.8]), frequent activity restriction (OR = 1.5 [1.2 to 1.8]), and, among those with labor force participation (n = 551), asthma-related cessation of employment (OR = 1.7 [1.1 to 2.4]). The PCAQ is a short, easy to administer, reliable, and valid measure of perceived control of asthma. It is strongly associated with adverse asthma outcomes even taking into account demographic characteristics and asthma severity, suggesting that patient-centered interventions focusing on perceived control might improve asthma outcomes.

Adolescent↗
PubMed1997

No evidence for effects of family environment on asthma. A retrospective study of Norwegian twins.

The risk of developing asthma contingent upon the co-twins' history of asthma was analyzed in a population-based study of 5,864 Norwegian twins. A primary aim was to assess the significance of shared environment for the development of asthma from infancy through age 25. Retrospective reports were collected when the twins were 18 to 25 yr of age. The risk of developing asthma, contingent upon the co-twin's history of asthma, was estimated using survival analyses, and genetic and environmental sources of variation in liability for asthma were analyzed with structural equation models. The cumulative incidence of asthma was 6% for males and 5.4% for females. The relative risk of developing asthma among twins whose co-twin had a positive history of asthma compared with those whose co-twin had no history of asthma was 17.9 (95% CI, 10.3 to 31.0) for identical, and 2.3 (95% CI, 1.2 to 4.4) for fraternal twins. Although shared environment encompasses many of the exposures that are putative risk factors for asthma in this age range, there is no evidence of shared environmental influences for asthma. Rather, 75% of the variation in liability for asthma was explained by genetic effects and the remaining variation was due to nonshared environmental influences. These results suggest that the familial risk for asthma is primarily, genetic.

Actuarial Analysis↗
PubMed1999

Prevalence of tumor necrosis factor-alpha and angiotensin converting enzyme polymorphisms in mild/moderate and fatal/near-fatal asthma.

Allele 2 of the polymorphism at position -308 in the promoter of the tumor necrosis factor alpha (TNF-alpha) gene, and the D allele of the angiotensin converting enzyme (ACE) gene, have been associated with asthma. We hypothesized that genotypes containing these alleles would show an increased prevalence in asthmatic as compared with nonasthmatic individuals, and would be associated with asthma severity. Polymerase chain reaction-based assays were developed to determine TNF-alpha and ACE genotypes among subjects with mild/moderate asthma (n = 92), fatal/near-fatal asthma (n = 159), no asthma (n = 43), and random population controls (n = 252). The TNF-alpha -308 polymorphism was increased in both subjects with mild/moderate (p = 0.03) and those with fatal/near fatal asthma (p = 0.02) versus those without asthma, and in all subjects with asthma versus random population controls (p = 0.02). The mild/moderate group was subdivided into subjects with mild (n = 43) and those with moderate (n = 33) asthma. TNF-alpha -308 was increased in the moderately asthmatic versus the nonasthmatic subjects (p = 0.003), and in the mildly asthmatic subjects (p = 0.01). However, TNF-alpha -308 was not significantly more prevalent in the fatal/near-fatal than in the mild/moderate asthmatic group. The ACE-D allele did not show an association with either asthma or asthma severity. We conclude that the TNF-alpha -308 polymorphism may be a risk factor for asthma but does not increase the risk of a fatal or a near-fatal asthma attack, whereas the ACE polymorphism is not associated with asthma in this population.

Adult↗
PubMed2000

The effect of age and duration of disease on airway structure in fatal asthma.

We hypothesized that if airway remodeling is related to duration of asthma, that when matched for severity, the airways of older adults should show greater alterations than the airways of younger adults. Using standard morphometric techniques, we compared airways with basement membrane perimeters (Pbm) between 2 and 10 mm from young individuals who died of asthma (n = 14, range 17-23 yr), and older individuals with fatal asthma (n = 13, range 40-49 yr). Comparisons were also made with normal airways from age-matched adults. Wall area was increased in old individuals with fatal asthma compared with young individuals with fatal asthma, primarily due to greater adventitial area, whereas wall area in young individuals with fatal asthma was not different from control subjects. Within muscle bundles the connective tissue matrix was increased around individual cells in individuals with asthma, unrelated to age. After adjustment for this change, smooth muscle area in both asthma groups was still greater than in age-matched control subjects, in old individuals with fatal asthma 4-fold greater (p = 0.04), and in young individuals with fatal asthma 2-fold greater (p = 0.03). Airway narrowing was increased in old versus young individuals with fatal asthma, with both groups more narrowed than control subjects. Intralumenal obstruction and subepithelial collagen in the two asthma groups were significantly greater than in control subjects, but there was no age effect. These data provide support for the hypothesis that there is an increase in airway wall area, including smooth muscle, and airway narrowing with increasing duration of severe asthma or with older age. The observation that total wall thickness was not greater in young individuals with young fatal asthma than in control subjects suggests that factors other than airway wall geometry contribute to the pathogenesis of fatal attacks in this age group.

Adolescent↗
PubMed2000

Inflammation and structural changes in the airways of patients with atopic and nonatopic asthma. BHR Group.

The aim of the present study was to compare the cellular pattern and structural changes in the airway walls of atopic and nonatopic patients with asthma. Bronchial biopsy specimens were obtained from 13 atopic subjects with asthma, nine nonatopic patients with asthma, and seven healthy control subjects and investigated using immunohistochemical methods. The number of eosinophils increased in both asthma groups, but significantly more in the atopic group. The number of mast cells increased similarly in the two asthma groups, whereas the number of neutrophils increased only in the nonatopic asthma group. The number of T-lymphocytes (CD3-, CD4-, CD8-, CD-25-positive cells) was higher in patients with atopic asthma compared with nonatopic asthma. Interleukin-4 (IL-4) and IL-5-positive cells were more frequently found in the atopic asthma group, whereas cells staining for IL-8 were more frequent in the nonatopic group. The degree of epithelial damage was significantly higher in the atopic asthma group compared with the control subjects and the nonatopic asthmatics. The tenascin and laminin layer was significantly thicker in the atopic group compared with the group of nonatopic asthmatics. In the atopic group, there was a significant negative correlation between epithelial integrity (defined as the relative length of intact epithelium) and the eosinophil count and also between the number of CD25-positive cells and epithelial integrity. The number of mast cells correlated positively with the thickness of tenascin- and laminin-positive layers. In conclusion, we provide evidence of different patterns of involvement of inflammatory cells in atopic and nonatopic patients with asthma. There were also structural differences in the bronchial mucous membrane between atopic asthma and nonatopic asthma. This suggests that there are differences in the extent of the immunopathologic response of these clinically distinct forms of asthma.

Adolescent↗
PubMed2001

Mild and moderate asthma is associated with airway goblet cell hyperplasia and abnormalities in mucin gene expression.

Excessive airway mucus is an important cause of morbidity and mortality in asthma, but the relationship between accumulation of mucus and goblet cell size, number, and function is incompletely understood. To address these questions, stored mucin in the epithelium and goblet cell size and number were measured morphometrically, and mucin gene expression was measured by polymerase chain reaction and immunohistochemistry in endobronchial biopsies from 13 subjects with mild and moderate asthma and from 12 healthy control subjects. Secreted mucin was measured in induced sputum. We found that stored mucin in the airway epithelium was three times higher than normal in the subjects with asthma (p < 0.005). Goblet cell size was similar in both groups, but goblet cell number was significantly higher in the subjects with asthma (93,043 +/- 15,824 versus 41,959 +/- 9,230/mm3, p < 0.05). In mild asthma (FEV1 > or = 80% pred, n = 7), the level of stored mucin was as high as in moderate asthma (FEV1 < 80% pred, n = 6), but the level of secreted mucin was significantly lower (28.4 +/- 6.3 versus 73.5 +/- 47.5 microg/ml, p < 0.05). Secreted mucin was inversely correlated with stored mucin for the whole asthma group (rs = -0.78, p = 0.007). MUC5AC was the predominant mucin gene expressed in healthy subjects and subjects with asthma, and MUC5AC protein was increased in the subjects with asthma. We conclude that even mild asthma is associated with goblet cell hyperplasia and increased stored mucin in the airway epithelium, whereas moderate asthma is associated with increased stored mucin and secreted mucin. These findings suggest that acute degranulation of hyperplastic goblet cells may represent a mechanism for asthma exacerbations in mild and moderate asthma and that chronic degranulation of goblet cells may contribute to chronic airway narrowing in moderate asthma.

Adult↗
PubMed2003

Airway inflammation in childhood asthma.

Airway pathology has been extensively investigated in adulthood asthma, whereas only few studies examined bronchial biopsies in childhood asthma. To evaluate the airway pathology in children with asthma, we analyzed bronchial biopsies obtained from 23 children undergoing bronchoscopy for clinical indications other than asthma. Nine had mild/moderate asthma. Six had atopy without asthma, and eight had no atopy or asthma. We measured basement membrane thickness and quantified the number of eosinophils, mast cells, neutrophils, macrophages, T lymphocytes, and positive cells for transforming growth factor-beta1 (TGF-beta1) and its receptors I and II (TGFbeta-RI and TGFbeta-RII) in subepithelium. Children with asthma had an increase in basement membrane thickness and in the number of eosinophils compared with control subjects, but not compared with children with atopy. They also had a decreased expression of TGFbeta-RII compared with both those with atopy and control subjects. In children with asthma, the number of eosinophils correlated negatively with TGFbeta-RII and positively with symptom duration. In conclusion, airway eosinophilia and basement membrane thickening, which are the pathologic features that are characteristic of adulthood asthma, are already present in children with mild asthma, and even in children with atopy without asthma. Moreover, in children with asthma but not in children with atopy without asthma, there is a downregulation of TGFbeta-RII.

Adolescent↗
PubMed2006

Epithelial damage and angiogenesis in the airways of children with asthma.

RATIONALE: Airway remodeling and inflammation are characteristic features of adult asthma that are still poorly investigated in childhood asthma. OBJECTIVES: To examine epithelial and vascular changes as well as the inflammatory response in airways of children with asthma. METHODS: We analyzed bronchial biopsies obtained from 44 children undergoing bronchoscopy for appropriate clinical indications other than asthma: 17 with mild/moderate asthma (aged 2-15 yr), 12 with atopy without asthma (1-11 yr), and 15 control children without atopy or asthma (1-14 yr). By histochemistry and immunohistochemistry, we quantified epithelial loss, basement membrane thickness, number of vessels, and inflammatory cells in subepithelium. RESULTS: Epithelial loss and basement membrane thickness were increased in children with asthma compared with control subjects (p = 0.005 and p = 0.0002, respectively) and atopic children (p = 0.002 and p = 0.005, respectively). The number of vessels and eosinophils was increased not only in asthmatic children (p = 0.03 and p = 0.0002, respectively) but also in atopic children without asthma (p = 0.03 and p = 0.008, respectively) compared with control subjects. When we stratified the analysis according to age, we observed that children with asthma younger than 6 yr had increased epithelial loss, basement membrane thickening, and eosinophilia compared with control subjects of the same age. CONCLUSIONS: Epithelial damage and basement membrane thickening, which are pathologic features characteristic of adult asthma, are present even in childhood asthma. Other changes, such as airway eosinophilia and angiogenesis, were also observed in atopic children without asthma. These observations suggest that pathologic changes occur early in the natural history of asthma and emphasize the concept that some of these lesions may characterize atopy even in the absence of asthmatic symptoms.

Adolescent↗
PubMed1999

Assessment of a simple scoring system applied to a screening questionnaire of asthma in children aged 5-15 yrs.

The aim of the present study was to validate a simple scoring system using a parent-completed screening questionnaire to identify children aged 5-15 yrs who may have asthma. A stratified random sample of 157 children of 1,808 whose parents had answered a postal respiratory questionnaire underwent detailed clinical evaluation. The results were reviewed by three independent paediatricians whose opinions were combined to reach, for each child, decisions regarding three standards: 1) "possible asthma" defined as >50% likelihood of having asthma; 2) "possible asthma" defined as meriting a clinical trial of asthma medication; and 3) "probable asthma" defined as >90% likelihood of having asthma. The combined decisions were compared to three sets of questionnaire scores, in order to determine the positive predictive value, sensitivity and specificity of each set in identifying children with probable/possible asthma. The three sets of chosen questionnaire scores all had positive predictive values of 79-96% for predicting possible asthma, using either the combined expert opinion ">50% likelihood of asthma" or that of "warrants a trial of treatment" as the definition. This suggests that a low proportion of false positives would be obtained were this scoring system to be used for a screening programme. The combined decision >90% chance of asthma could be used as a means of estimating prevalence of asthma in the survey. When used for this, the prevalence of asthma in the surveyed population was 18.8% (95% confidence interval 13.1-26.3). In conclusion, the present scoring system, based on a simple respiratory questionnaire, provides a valid method of identifying children likely to have asthma, and who, if unknown to the medical services, would benefit from clinical review.

Adolescent↗
PubMed2005

Ethnic variations in incidence of asthma episodes in England & Wales: national study of 502,482 patients in primary care.

BACKGROUND: Recent studies have demonstrated marked international variations in the prevalence of asthma, but less is known about ethnic variations in asthma epidemiology within individual countries and in particular the impact of migration on risk of developing asthma. Recent within country comparisons have however revealed that despite originating from areas of the world with a low risk for developing asthma, South Asian and Afro-Caribbean people in the UK are significantly (3x and 2x respectively) more likely to be admitted to hospital for asthma related problems than Whites. METHODS: Using data from the Fourth National Study of Morbidity Statistics in General Practice, a one-percent broadly representative prospective cohort study of consultations in general practice, we investigated ethnic variations in incident asthma consultations (defined as new or first consultations), and compared consultation rates between those born inside and outside the UK (migrant status). Logistic regression models were used to examine the combined effects of ethnicity and migration on asthma incident consultations. RESULTS: Results showed significantly lower new/first asthma consultation rates for Whites than for each of the ethnic minority groups studied (mean age-adjusted consultation rates per 1000 patient-years: Whites 26.4 (95%CI 26.4, 26.4); South Asians 30.4 (95%CI 30.3, 30.5); Afro-Caribbeans 35.1 (95%CI 34.9, 35.3); and Others 27.8 (27.7, 28.0). Within each of these ethnic groups, those born outside of the UK showed consistently lower rates of incident asthma consultations. Modelling the combined effects of ethnic and migrant status revealed that UK-born South Asians and Afro-Caribbeans experienced comparable risks for incident GP consultations for asthma to UK-born Whites. Non-UK born Whites however experienced reduced risks (adjusted OR 0.82, 95%CI 0.69, 0.97) whilst non-UK born South Asians experienced increased risks (adjusted OR 1.33, 95%CI 1.04, 1.70) compared to UK-born Whites. CONCLUSION: These findings strongly suggest that ethnicity and migration have significant and independent effects on asthma incidence. The known poorer asthma outcomes in UK South Asians and Afro-Caribbeans may in part be explained by the offspring of migrants experiencing an increased risk of developing asthma when compared to UK-born Whites. This is the first study to find heterogeneity for incident asthma consultations in Whites by migrant status.

Adult↗
PubMed2005

Clinically diagnosed childhood asthma and follow-up of symptoms in a Swedish case control study.

BACKGROUND: Childhood asthma has risen dramatically not only in the western societies and now forms a major and still increasing public health problem. The aims of this study were to follow up at the age of ten the patterns of asthma symptoms and associations among children with a clinically diagnosed asthma in a sizeable urban-rural community and to in compare them with demographic controls using a standardised questionnaire. METHODS: In a defined region in Sweden with a population of about 150,000 inhabitants, all children (n = 2,104) born in 1990 were recorded. At the age of seven all primary care and hospital records of the 1,752 children still living in the community were examined, and a group of children (n = 191) was defined with a well-documented and medically confirmed asthma diagnosis. At the age of ten, 86 % of these cases (n = 158) and controls (n = 171) completed an ISAAC questionnaire concerning asthma history, symptoms and related conditions. RESULTS: Different types of asthma symptoms were highly and significantly over-represented in the cases. Reported asthma heredity was significantly higher among the cases. No significant difference in reported allergic rhinitis or eczema as a child was found between cases and controls. No significant difference concerning social factors or environmental exposure was found between case and controls. Among the control group 4.7 % of the parents reported that their child actually had asthma. These are likely to be new asthma cases between the age of seven and ten and give an estimated asthma prevalence rate at the age of ten of 15.1 % in the studied cohort. CONCLUSION: A combination of medical verified asthma diagnosis through medical records and the use of self-reported symptom through the ISAAC questionnaire seem to be valid and reliable measures to follow-up childhood asthma in the local community. The asthma prevalence at the age of ten in the studied birth cohort is considerably higher than previous reports for Sweden. Both the high prevalence figure and allowing the three-year lag phase for further settling of events in the community point at the complementary roles of both hospital and primary care in the comprehensive coverage and control of childhood asthma in the community.

Asthma↗
PubMed2005

Using the ecology model to describe the impact of asthma on patterns of health care.

BACKGROUND: Asthma changes both the volume and patterns of healthcare of affected people. Most studies of asthma health care utilization have been done in selected insured populations or in a single site such as the emergency department. Asthma is an ambulatory sensitive care condition making it important to understand the relationship between care in all sites across the health service spectrum. Asthma is also more common in people with fewer economic resources making it important to include people across all types of insurance and no insurance categories. The ecology of medical care model may provide a useful framework to describe the use of health services in people with asthma compared to those without asthma and identify subgroups with apparent gaps in care. METHODS: This is a case-control study using the 1999 U.S. Medical Expenditure Panel Survey. Cases are school-aged children (6 to 17 years) and young adults (18 to 44 years) with self-reported asthma. Controls are from the same age groups who have no self-reported asthma. Descriptive analyses and risk ratios are placed within the ecology of medical care model and used to describe and compare the healthcare contact of cases and controls across multiple settings. RESULTS: In 1999, the presence of asthma significantly increased the likelihood of an ambulatory care visit by 20 to 30% and more than doubled the likelihood of making one or more visits to the emergency department (ED). Yet, 18.8% of children and 14.5% of adults with asthma (over a million Americans) had no ambulatory care visits for asthma. About one in 20 to 35 people with asthma (5.2% of children and 3.6% of adults) were seen in the ED or hospital but had no prior or follow-up ambulatory care visits. These Americans were more likely to be uninsured, have no usual source of care and live in metropolitan areas. CONCLUSION: The ecology model confirmed that having asthma changes the likelihood and pattern of care for Americans. More importantly, the ecology model identified a subgroup with asthma who sought only emergent or hospital services.

Adult↗