The rising prevalence of asthma in young Melbourne adults is associated with improvement in treatment

Associations of atopy and asthma during aging of an adult population over a 20-year follow-up

OBJECTIVE

Atopy is associated with asthma, but cross-sectional studies suggest this association may be weaker in older adults. It remains unclear if atopy predicts asthma later in adult life. We aimed to investigate whether atopy in young adults predicted asthma 20 years later and to quantify the contemporaneous relationship of atopy and asthma as adults age.

METHODS

Participants of the European Community Respiratory Health Survey (ECRHS) in Melbourne aged 20-44 years were followed for 20 years and completed questionnaires, skin prick tests (SPT) and allergen specific immunoglobulin E measurement at a baseline and two subsequent surveys. Using logistic regression and generalized estimating equations, we tested if atopy at baseline predicted current asthma later in life and estimated the association between current atopy measured at each survey and current asthma, while adjusting for potential confounders.

RESULTS

The analysis included 220 participants: 50.9% male. Mean (SD) age at baseline was 35.7 (5.7) years. Asthma and atopy prevalence remained stable over 20 years. Baseline atopy (SPT) was associated with current asthma (OR 9.74, 95%CI 4.22, 22.5) over 20 years, and current atopy (SPT) with concurrent asthma (3.12; 1.70, 5.74).

CONCLUSIONS

Atopy remains strongly associated with current asthma in 40 to 64 year-old adults, both prospectively and contemporaneously, but the prospective association is stronger.

Ten-year trends in prevalence of asthma in adults in southern Brazil: comparison of two population-based studies

There are discrepancies in the literature regarding time trends in the occurrence of asthma in adults. This study compared asthma prevalence in two cross-sectional studies with a ten-year interval in Pelotas, Rio Grande do Sul State, Brazil. The first, in 2000, included 1,968 individuals, and the second, in 2010, 2,466 adults (20-69 years). Prevalence of wheezing and shortness of breath in the prior 12 months remained the same after ten years (6% and 6.1%, respectively). In both studies, asthma was more frequent among females and people with low family income. Physician-diagnosed asthma increased by 35.6%, and lifetime incidence of asthma, by 32.2%. There was no percentage change in current asthma symptoms or current asthma. Local socioeconomic improvement between the two studies was consistent with the increase in medical diagnosis, but did not reflect better management of asthma symptoms, underlining the need for investment regarding other determinants of the disease.

Longitudinal associations of adiposity with adult lung function in the Childhood Determinants of Adult Health (CDAH) study

Childhood BMI has been reported to be positively associated with adult lung function. The aim of this study was to investigate the effect of childhood BMI on young adult lung function independently of the effects of lean body mass (LBM). Clinical and questionnaire data were collected from 654 young Australian adults (aged 27-36 years), first studied when age 9, 12, or 15 years. Adult lung function was measured by forced vital capacity (FVC), forced expiratory volume in 1 s (FEV(1)), FEV(1)/FVC ratio, and the forced expiratory flow in the middle 50% of FVC (FEF(25-75)). BMI and LBM were derived from anthropometric measures at baseline (1985) and at follow-up (2004-2006). Multivariable models were used to investigate the effect of age and sex standardized BMI in childhood on adult lung function, before and after adjustment for LBM. Adult adiposity had a strong deleterious effect on lung function, irrespective of childhood BMI, and adjustment for childhood LBM eliminated any apparent beneficial effect of childhood BMI on adult FEV(1) or FVC. This suggests that the beneficial effect of increased BMI in childhood on adult FEV(1) and FVC observed in previous longitudinal studies is likely to be attributable to greater childhood LBM not adiposity. Obese children who become obese adults can expect to have poorer lung function than those who maintain healthy weight but large deficits in lung function are also likely for healthy weight children who become obese adults. This highlights the importance of lifetime healthy weight maintenance.

Increased prevalence of symptoms of rhinitis but not of asthma between 1990 and 2008 in Swedish adults: comparisons of the ECRHS and GA²LEN surveys

Background

The increase in asthma prevalence until 1990 has been well described. Thereafter, time trends are poorly known, due to the low number of high quality studies. The preferred method for studying time trends in prevalence is repeated surveys of similar populations. This study aimed to compare the prevalence of asthma symptoms and their major determinants, rhinitis and smoking, in Swedish young adults in 1990 and 2008.

Methods

In 1990 the European Community Respiratory Health Survey (ECRHS) studied respiratory symptoms, asthma, rhinitis and smoking in a population-based sample (86% participation) in Sweden. In 2008 the same symptom questions were included in the Global Allergy and Asthma European Network (GA²LEN) survey (60% participation). Smoking questions were however differently worded. The regions (Gothenburg, Uppsala, Umeå) and age interval (20–44 years) surveyed both in 1990 (n = 8,982) and 2008 (n = 9,156) were analysed.

Results

The prevalence of any wheeze last 12 months decreased from 20% to 16% (p<0.001), and the prevalence of “asthma-related symptoms” was unchanged at 7%. However, either having asthma attacks or using asthma medications increased from 6% to 8% (p<0.001), and their major risk factor, rhinitis, increased from 22% to 31%. Past and present smoking decreased.

Conclusion

From 1990 to 2008 the prevalence of obstructive airway symptoms common in asthma did not increase in Swedish young adults. This supports the few available international findings suggesting the previous upward trend in asthma has recently reached a plateau. The fact that wheeze did not increase despite the significant increment in rhinitis, may at least in part be due to the decrease in smoking.

[Changes in the prevalence of asthma in the Spanish cohort of the European Community Respiratory Health Survey (ECRHS-II)]

OBJECTIVE

The rise in the prevalence of asthma in the second half of the 20th century has not been evenly distributed according to recent surveys. We assessed changes in the prevalence of asthma after a period of 9 to 10 years in a cohort of young adults in the Spanish arm of the European Community Respiratory Health Survey (ECRHS).

MATERIAL AND METHODS

The ECRHS-II is a multicenter cohort study taking place in 27 centers around Europe, with Spanish centers located in Albacete, Barcelona, Galdakao, Huelva, and Oviedo. The ECRHS questionnaire was administered to individuals who had participated in the first phase of the survey; spirometry and methacholine challenge tests were also performed according to the published protocol.

RESULTS

Among new smokers, the prevalence of wheezing in the last 12 months increased from 10% to 33%, while the frequency of phlegm production rose from 8% to 22% (P< .05). In ex-smokers, the prevalences of wheezing and phlegm production decreased from 21% to 12% and from 15% to 8%, respectively (P< .05). Symptom prevalences remained similar for never smokers, although the frequency of diagnosed asthma rose from 4% to 7% (P< .05). After adjusting for smoking, age, sex, and center, we found no significant differences in the frequency of symptoms or asthma, even when the phrase bronchial hyperreactivity was included in the definition. However, the rate of reported asthma rose annually by 0.34% (95% confidence interval [CI], 0.20%-0.48%), while diagnosed asthma rose by 0.26% (95% CI, 0.13%-0.39%) and treated asthma by 0.16% (95% CI, 0.07%-0.25%).

CONCLUSIONS

Increased prevalence rates of asthma diagnosis and treatment have been detected, but the rates of reported symptoms have remained similar, consistent with the assumption that more persons are being classified as asthmatics.

Long-acting beta2-agonists for chronic asthma in adults and children where background therapy contains varied or no inhaled corticosteroid

BACKGROUND

Asthma is a common respiratory disease among both adults and children and short acting inhaled beta-2 agonists are used widely for 'reliever' bronchodilator therapy. Long acting beta-2 agonists (LABA) were introduced as prospective 'symptom controllers' in addition to inhaled corticosteroid 'preventer' therapy (ICS). In this updated review we have included studies in which patients were either not on ICS as a group, or in which some patients, but not all, were on ICS to complement previous systematic reviews of studies where LABA was given in patients uniformly receiving ICS. We have focussed particularly on serious adverse events, given previous concerns about potential risks, especially of death, from regular beta-2 agonist use.

OBJECTIVES

This review aimed to determine the benefit or detriment on the primary outcome of asthma control with the regular use of LABA compared with placebo, in mixed populations in which only some were taking ICS and in populations not using ICS therapy.

SEARCH STRATEGY

We carried out searches using the Cochrane Airways Group trial register, most recently in October 2005. We searched bibliographies of identified RCTs for additional relevant RCTs and contacted authors of identified RCTs for other published and unpublished studies.

SELECTION CRITERIA

All randomised studies of at least four weeks duration, comparing a LABA given twice daily with a placebo, in chronic asthma. Selection criteria to this updated review have been altered to accommodate recently published Cochrane reviews on combination and addition of LABA to ICS therapy. Studies in which all individuals were uniformly taking ICS were excluded from this review.

DATA COLLECTION AND ANALYSIS

Two reviewers performed data extraction and study quality assessment independently. We contacted authors of studies for missing data.

MAIN RESULTS

Sixty-seven studies (representing 68 experimental comparisons) randomising 42,333 participants met the inclusion criteria. Salmeterol was used as long-acting agent in 50 studies and formoterol fumarate in 17. The treatment period was four to nine weeks in 29 studies, and 12 to 52 weeks in 38 studies. Twenty-four studies did not permit the use of ICS, and forty permitted either inhaled corticosteroid or cromones (in three studies this was unclear). In these studies between 22% and 92% were taking ICS, with a median of 62%. There were significant advantages to LABA treatment compared to placebo for a variety of measurements of airway calibre including morning peak expiratory flow (PEF), evening PEF and FEV1. They were associated with significantly fewer symptoms, less use of rescue medication and higher quality of life scores. This was true whether patients were taking LABA in combination with ICS or not. Findings from SMART (a recently published surveillance study) indicated significant increases in asthma related deaths, respiratory related deaths and combined asthma related deaths and life threatening experiences. The absolute increase in asthma-related mortality was consistent with an increase of around one per 1250 patients treated with LABA for six months, but the confidence intervals are wide (from 700 to 10,000). Post-hoc exploratory subgroups suggested that African-Americans and those not on inhaled corticosteroids were at particular risk for the primary end-point of death or life-threatening asthma event. There was also a suggestion of an increase in exacerbation rate in children. Pharmacologically predicted side effects such as headache, throat irritation, tremor and nervousness were more frequent with LABA treatment.

AUTHORS' CONCLUSIONS

LABA are effective in the control of chronic asthma in the "real-life" subject groups included. However there are potential safety issues which call into question the safety of LABA, particularly in those asthmatics who are not taking ICS, and it is not clear why African-Americans were found to have significant differences in comparison to Caucasians for combined respiratory-related death and life threatening experiences, but not for asthma-related death.

An investigation of the housing environment for persons with asthma and persons without asthma

Asthma is a chronic disease affected by environmental factors that may increase symptoms that impact on a persons' well-being. An important issue in occupational therapy is to improve the relationship between a person's functional capacity and the physical environment. The aim of the study was to compare the housing environment of persons with asthma (cases, n = 49) and persons without asthma (controls, n = 48), with regard to building construction and condition, physical, chemical and biological factors, and cleaning routines. A secondary aim was to compare different types of accommodation within cases and controls. A specialist team, including a construction engineer, a biological scientist, and an occupational therapist, conducted the study. Data were collected using protocols, as well as a number of established technical methods from the field of occupational and environmental medicine. The primary results showed no major differences in the housing environment between the two groups. However, in individual homes environmental factors at levels that could increase symptoms were identified. When single-family houses were compared with multi-family houses, significant differences were found indicating that preventive interventions may be needed in some single-family houses. Further studies are needed to clarify the person-environment relationship for persons with asthma, focusing on their ability to perform daily activities.

Trends in asthma prevalence and population changes in South Australia, 1990-2003

OBJECTIVES

To examine changes in asthma prevalence in the context of other population changes between 1990 and 2003, for specific age and sex groups.

DESIGN

Cross-sectional survey based on household interviews, repeated annually.

SETTING AND PARTICIPANTS

Representative samples of the South Australian population between 1990 and 2003 (around 3000 people per year).

MAIN OUTCOME MEASURES

Current prevalence of doctor-diagnosed asthma and other health and demographic variables potentially associated with asthma, and asthma management.

RESULTS

Response rate was over 71%. Between 1990 and 2003, asthma prevalence increased significantly, doubling in females (from 7.3% in 1990 to 14.6% in 2003), with a smaller increase in males (from 7.8% to 9.4%). Asthma also increased in all age groups, but the largest relative increases occurred in people aged 55 years and older. Logistic regression analyses showed that obesity was a major predictive variable for every age group studied. The prevalence of asthma morbidity (waking at night and days lost from usual activities because of asthma) among those with asthma showed no significant changes between 1990 and 2003. Asthma action plans (introduced on a population basis in 1992) peaked in their distribution at 42% in 1994, and then declined to half that percentage in 2003. The increase in asthma prevalence occurred at the same time as increases in population prevalence of obesity (10.3% to 18.7%) and diabetes (3.1% to 6.9%), and decline in recent vigorous exercise (42.4% to 32.7%).

CONCLUSIONS

The increase in asthma prevalence over a decade was large, but concentrated among specific sex and age groups. The increase accompanied population increases in obesity and diabetes and a decline in vigorous exercise.

The burden of asthma in children: an Australian perspective

The burden of asthma among children is high in Australia compared with many other countries. Recent data show that 14-16% of children report a diagnosis of asthma that remains a problem. Boys, children under the age of 5 years and urban indigenous children experience a greater burden of asthma than other children. More than one-third of children with asthma have sleep disturbance due to the illness and 60% have missed school and/or experienced other restrictions in their activities due to the disease. Despite this, there is continuing evidence of under-utilisation of effective treatment for the disease. Asthma is a major cause of healthcare utilisation among children. Since the early 1990s, there has been a decline in both hospitalisation rates and general practitioner consultation rates for asthma among children. It remains to be seen whether this favourable trend will continue and extend into the adult age range.

Signs of reversing trends in prevalence of asthma

Several recent reports have provided evidence that the burden of asthma may have levelled off, after increasing for decades. Implementation of the national and global asthma prevention and management guidelines that have led to earlier detection and improved treatment of asthmatics, is considered to be involved in this apparent change for the better. In addition, environmental influences associated with the modern life may have reached the maximum in inducing symptoms and disease in genetically susceptible individuals in some areas. Available data obtained from Canada and non-English-speaking countries in Europe show that the peak in asthma prevalence has been reached at the level of 8-12%. This review outlines the most recent literature on time trends in asthma prevalence and considers the possible causes of the current trends. Problems and pitfalls in appraising studies on time trends are also discussed.

Induction of T 'regulatory' cells by standardized house dust mite immunotherapy: an increase in CD4+ CD25+ interleukin-10+ T cells expressing peripheral tissue trafficking markers

BACKGROUND

Clinically effective subcutaneous allergen-specific immunotherapy (SIT) is associated with altered circulating T cell cytokine production and altered local cytokine responses with increased IL-10 following allergen challenge in target organs.

OBJECTIVE

This study aimed to elucidate mechanisms for these T cell changes, by examining surface expression of markers for peripheral tissue trafficking on circulating cytokine-positive T cells following standardized house dust mite- (HDM-) SIT.

METHODS

A randomized conventional HDM immunotherapy study was performed on a panel of 12 HDM-allergic subjects. Nine subjects received treatment with conventional HDM immunotherapy using a standardized extract and three subjects were treated by standard pharmacotherapy alone. Symptom and medication scores and allergen-induced cutaneous late-phase responses were assessed before and 9 months after institution of therapy. Before and at 3 and 9 months of SIT, peripheral blood mononuclear cells were cultured for 14 days with HDM extract and CD4+ and CD8+ T cell expression of CD62L, CD49d and CCR5 and production of IL-10, IFN-gamma and IL-4 were analysed by flow cytometry. Allergen-specific T cell proliferation was assessed by 3H-thymidine incorporation.

RESULTS

At 9 months, all SIT-treated patients showed reduced symptom scores and late-phase cutaneous responses to HDM compared with baseline levels. The proportions of CD4+ T cells which were IL-10+ were increased (P < 0.01), and the proportions of CD4+ and CD8+ T cells which were IL-4+ decreased (P < 0.05) compared with baseline. CD4+ and CD8+ T cell IFN-gamma production, expression of surface markers for peripheral tissue trafficking and allergen-specific proliferation remained unchanged during SIT treatment. However, increased proportions of CD4+CD62L(-), CD4+CD49d(hi), CD4+CCR5+ T cells expressing IL-10 were detected at 9 months of SIT compared with baseline (P < 0.05). IL-10 staining co-localized with CD4+CD25+ T cells.

CONCLUSION

Clinically effective subcutaneous immunotherapy with a standardized HDM Dermatophagoides pteronyssinus preparation results in decreased numbers of IL-4+ T cells and expansion of CD4+IL-10+ T cells expressing a peripheral tissue trafficking phenotype. The co-localization of IL-10+ staining to CD4+CD25+ T cells is consistent with the induction of a T regulatory cell population by SIT.

Fatty acid levels and risk of asthma in young adults

BACKGROUND

There is current interest in the possible protective effect of long chain (n-3) fatty acids from fish in chronic lung diseases such as asthma. The aim of this community based cross sectional study was to determine whether plasma long chain (n-3) fatty acids, as a measure of dietary intake, differed between 1601 young adults with and without asthma.

METHODS

Subjects of mean (SD) age 34.6 (7.1) years completed a detailed respiratory questionnaire, food frequency questionnaire, skin prick testing, and lung function tests including methacholine challenge test for bronchial hyperreactivity (BHR) and had venous blood taken for analysis of plasma fatty acids. Plasma fatty acid levels (%) were analysed using multiple logistic regression with alternative definitions of asthma and atopy as the outcomes.

RESULTS

Atopy was not associated with any plasma fatty acid. The n-3 polyunsaturated fatty acids and n-6:n-3 ratio were not consistently associated with asthma or atopy. The n-6 polyunsaturated fatty acid dihomo gamma-linolenic acid (DHGLA) was positively associated with current asthma (OR=1.30, 95% CI 1.06 to 1.60), asthma (OR=1.34, 95% CI 1.13 to 1.60), and doctor diagnosed asthma (OR=1.25, 95% CI 1.06 to 1.48).

CONCLUSION

Plasma n-3 fatty acids are not associated with a reduced risk of asthma or atopy among young adults. The association of DHGLA with asthma warrants further research to determine a cause-effect relationship.

Prevalence of asthma and related symptoms in Sivas, Central Anatolia

BACKGROUND

In our clinical experience, asthma is an important health problem in our region, but we did not know its prevalence.

OBJECTIVE

The main objective of our study was to assess the prevalence of asthma in Sivas, a city in Central Anatolia.

METHODS

A cross-sectional study was performed using a screening questionnaire adopted from European Community Respiratory Health Survey (ECRHS). A total of 5448 adults of both genders between 20 and 107 yr of age living in Sivas, a city in the central region of Anatolia in Turkey, participated in the survey. Of the cohort, 2691 were men (49.4%) and 2757 (50.6%) were women.

RESULTS

The mean age was 38.2 yr (SD = 12.7 yr), almost half of the study population was at or younger than 40 yr of age. The prevalence of wheezing in the last 12 months, diagnosis of asthma, asthma attack in the last 12 months, and use of asthma medicine were 20.9%, 4.5%, 4.9%, and 3.4%, respectively. Awakening with chest tightness, with shortness of breath, or with cough were reported as 14.2%, 14.8%, and 22.7%, respectively. The prevalence of respiratory symptoms related to asthma was statistically higher in women than that of men (p = 0.000, OR 1.346, 95% CI: 1.228-1.475). Those who had asthma/allergic symptoms in their family members were significantly younger than others (p: 0.001).

CONCLUSIONS

The results of this study demonstrate that symptoms suggestive of asthma are quite common and constitute a major health problem in Sivas, Turkey. This study also showed that, despite a high rate of reported symptoms exists, the rate of diagnosis and treatment of asthma is low among the adult population in Sivas.

Food and nutrient intakes and asthma risk in young adults

BACKGROUND

Some aspects of diet are relatively newly recognized potential risk factors for asthma, but the evidence to date is conflicting.

OBJECTIVE

The goal was to determine whether the food and nutrient intakes of adults with asthma differ from those of adults without asthma.

DESIGN

This was a community-based, cross-sectional study of 1601 young adults ( +/- SD age: 34.6 +/- 7.1 y) who were initially recruited by random selection from the federal electoral rolls in Melbourne in 1999. Subjects completed a detailed respiratory questionnaire, a validated semiquantitative food-frequency questionnaire, skin-prick testing, and lung function tests, including a methacholine challenge test for bronchial hyperreactivity (BHR). A total of 25 nutrients and 47 food groups were analyzed by using multiple logistic regression with alternate definitions of asthma and atopy as the outcomes.

RESULTS

Whole milk appeared to protect against current asthma (odds ratio: 0.66; 95% CI: 0.46, 0.97), doctor-diagnosed asthma (0.73; 0.54, 0.99), BHR (0.68; 0.48, 0.92), and atopy (0.71; 0.54, 0.94). Conversely, soy beverage was associated with an increased risk of current asthma (2.05; 1.19, 3.53), doctor-diagnosed asthma (1.69; 1.04, 2.77), and BHR (1.65; 1.00, 2.71). Apples and pears appeared to protect against current asthma (0.83; 0.71, 0.98), asthma (0.88; 0.78, 1.00), and BHR (0.88; 0.77, 1.00).

CONCLUSIONS

The consumption of dairy products, soy beverages, and apples and pears, but not of nutrients per se, was associated with a range of asthma definitions. Dietary modification after diagnosis is one possible explanation for this finding. Intervention studies using whole foods are required to ascertain whether such modifications of food intake could be beneficial in the prevention or amelioration of asthma.

Is the prevalence of adult asthma and allergic rhinitis still increasing? Results of an Italian study

BACKGROUND

The prevalence of asthma and allergic rhinitis has increased worldwide during the 1970s and 1980s.

OBJECTIVE

This study was aimed at evaluating whether the increasing trend in prevalence persisted during the 1990s in the young adult Italian population.

METHODS

In 1998 to 2000 a screening questionnaire was sent by mail to a general population sample aged 20 to 44 years; nonresponders were contacted again first by mail and then by phone, achieving a final response rate of 78.1% (6876 of 8800). Prevalence estimates, adjusted to correct for nonresponse bias, were compared with those recorded in Italy in 1991 to 1993 during the European Community Respiratory Health Survey, when response rate had been slightly higher (87.6%). Temporal variations in symptom prevalence were analyzed by a logistic regression model, controlling for sex, age, site of residence (urban vs suburban areas), season of response, response rate, and type of contact (mail vs phone).

RESULTS

The prevalence of asthma attacks did not vary significantly from 1991 to 1993 (3.6%) to 1998 to 2000 (3.2%) (P =.188). The prevalence of asthma-like symptoms (wheezing, chest tightness, shortness of breath) tended to decrease in the age classes of 32.5 to 45 years, while increasing in the youngest age class (20 to 26 years). A clear-cut increase from 15.4% to 18.3% was observed for the prevalence of allergic rhinitis (P <.001), whereas the proportion of people under antiasthmatic treatment increased in suburban areas but not in urban areas (interaction time-site of residence, P <.001).

CONCLUSION

Asthma prevalence has not increased during the last decade in Italy. The persistence of an increasing trend in allergic rhinitis prevalence deserves attention.

Inhaled long acting beta agonists for stable chronic asthma

BACKGROUND

Asthma is a common respiratory disease among both adults and children and short acting inhaled beta-2 agonists are used widely for 'reliever' bronchodilator therapy. Long acting beta-2 agonists were introduced as prospective 'symptom controllers' in addition to inhaled corticosteroid 'preventer' therapy (ICS).

OBJECTIVES

This review aimed to determine the benefit or detriment on the primary outcome of asthma control with the regular use of long acting inhaled beta-2 agonists compared with placebo.

SEARCH STRATEGY

We carried out searches using the Cochrane Airways Group trial register, most recently in October 2002. We searched bibliographies of identified RCTs for additional relevant RCTs and contacted authors of identified RCTs for other published and unpublished studies.

SELECTION CRITERIA

All randomised studies of at least two weeks duration, comparing a long acting inhaled beta-agonist given twice daily with a placebo, in chronic asthma.

DATA COLLECTION AND ANALYSIS

Two reviewers performed data extraction and study quality assessment independently. We contacted authors of studies for missing data.

MAIN RESULTS

Eighty five studies met the inclusion criteria, 56 parallel group and 29 cross over design. Salmeterol xinafoate was used as long acting agent in 60 studies and formoterol fumarate in 25. The treatment period was two to four weeks in 32 studies, and 12 to 52 weeks in 53 studies. 34 study groups used concurrent inhaled corticosteroid treatment, 21 studies did not permit their use and 35 permitted either inhaled corticosteroid or cromones. There were significant advantages to long acting beta-2 agonist treatment compared to placebo for a variety of measurements of airway calibre including morning peak expiratory flow (PEF) (weighted mean difference (WMD) 26.78 L/min 95%CI 20.36 to 33.20), evening PEF (WMD 19.17 L/min 95%CI 11.63 to 26.73). They were associated with significantly fewer symptoms, less use of rescue medication and higher quality of life scores. The risk of exacerbation was lower in adults using regular inhaled corticosteroids.

REVIEWER'S CONCLUSIONS

Long acting beta-2 agonists are effective in the control of chronic asthma, and the evidence supports their use in addition to inhaled corticosteroids, as emphasised in current guidelines. Further research is needed on their use in children under 12 and in mild asthmatics not taking ICS.

Food allergy: what can be done to prevent progression to asthma?

OBJECTIVES

The primary objective of this review is to discuss risk factors for asthma development in food allergen-sensitized children. In the paper we discuss the possible measures to prevent progression to asthma by allergen and other adjuvant factor avoidance.

DATA SOURCES

A review from literature of articles on these topics was performed.

STUDY SELECTION

Relevant publications on asthma risk factors and implementation of protective factors were critically evaluated.

RESULTS

Children with familiar history of atopy and sensitization to food proteins in early infancy are at high risk of subsequent respiratory allergic diseases and require specific prevention. Because early allergic sensitization is a significant risk factor for later development of asthma, prevention of asthma by early allergen avoidance is mandatory in high-risk children. Adjuvant factors such as tobacco smoke and mold exposure may act as nonspecific triggers for the development of atopy. The role of protective factors such as infections in early life, breast-feeding, a "healthy" diet needs to be evaluated in prospective studies. Pharmacologic intervention with antihistamines led to significant reduction in incidence of asthma in high-risk children, but confirmatory longitudinal studies in large populations are necessary.

CONCLUSIONS

There is now accumulating evidence that preventing exposure to house-dust mite may significantly reduce the prevalence of childhood asthma. However, allergen avoidance can not be recommended as the only strategy. Avoidance of adjuvant factors and implementation of potential protective factors aimed to reduce the risk to progression to asthma need to be evaluated in prospective studies.

Asthma management: how effective is it in the community?

BACKGROUND

The National Asthma Campaign (NAC) was launched in Australia in 1989 with the major objective of improving asthma management through the implementation of a six-step asthma management plan.

AIM

The objective of the present study was to analyse the management of asthma in a cohort of adults with self-reported asthma 10 years after the commencement of the NAC.

METHODS

The subjects were participants in the laboratory phase of a cross-sectional epidemiological study conducted in Melbourne in 1999-2000. Participants completed the detailed European Community Respiratory Health Survey, which included specific questions about their asthma management. Participants were included in this analysis if they had a positive response to the question 'Have you ever had asthma?'. This resulted in a total of 435 subjects.

RESULTS

Of the subjects with self-reported asthma, over half of the participants reported that a doctor had ever measured their breathing (52.9%). However, only 10.1% of participants reported that they owned a peakflow meter (PFM) and only 13.3% reported that they had ever been given a written action plan. In comparison with data reported from 1993, doctor measurement of lung function has decreased significantly (P < 0.000 1), as has PFM ownership (P < 0.0001) and, importantly, possession of a written action plan (P = 0.0004).

CONCLUSIONS

Asthma management among adults still falls well short of NAC guidelines. The decline in some key features over recent years suggests that new management and dissemination strategies are required.

Regular treatment with long acting beta agonists versus daily regular treatment with short acting beta agonists in adults and children with stable asthma

BACKGROUND

Selective beta-adrenergic agonists for use in asthma are: short acting (2-6 hours) and long acting (>12 hours). There has been little controversy about using short acting beta-agonists intermittently, but long acting beta-agonists are used regularly, and their regular use has been controversial.

OBJECTIVES

To determine the benefit or detriment of treatment with regular short- or long acting inhaled beta-agonists in chronic asthma.

SEARCH STRATEGY

A search was carried out using the Cochrane Airways Group register. Bibliographies of identified RCTs were searched for additional relevant RCTs. Authors of identified RCTs were contacted for other published and unpublished studies.

SELECTION CRITERIA

All randomised studies of at least two weeks duration, comparing a long acting inhaled beta-agonist given twice daily with any short acting inhaled beta-agonist of equivalent bronchodilator effectiveness given regularly in chronic asthma.

DATA COLLECTION AND ANALYSIS

Two reviewers performed data extraction and study quality assessment independently. Authors of studies were contacted for missing data.

MAIN RESULTS

31 studies met the inclusion criteria, 24 of parallel group and 7 cross over design. Salmeterol xinafoate was used as long acting agent in 22 studies and formoterol fumarate in 9. Salbutamol was the short acting agent used in 27 studies and terbutaline in 5. The treatment period was over 2 weeks in 29 studies, and at least 12 weeks in 20. 25 studies permitted a variety of co-intervention treatments, usually inhaled corticosteroid or cromones. One study did not permit inhaled corticosteroid. Long acting beta-agonists were significantly better than short acting for a variety of lung function measurements including morning PEF (Weighted Mean Difference (WMD) 33 l/min 95% CI 25, 42) or evening PEF (WMD 26 l/min 95% CI 18, 33); and had significantly lower scores for day and night time asthma symptom scores and percentage of days and nights without symptoms. They were also associated with a significantly lower use of rescue medication both during the day and night. Risk of exacerbations was not different between the two types of agent, but most studies were of short duration which limits the power to test for such differences.

REVIEWER'S CONCLUSIONS

Long acting inhaled beta-agonists have advantages across a wide range of physiological and clinical outcomes for regular treatment.